CA3058452A1

CA3058452A1 - Managed pressure drilling manifold, modules, and methods

Info

Publication number: CA3058452A1
Application number: CA3058452A
Authority: CA
Inventors: Barton Hickie
Original assignee: Tech Energy Products LLC
Current assignee: Tech Energy Products LLC
Priority date: 2017-03-31
Filing date: 2018-03-30
Publication date: 2018-10-04
Also published as: WO2018183861A1; CN110892130A

Abstract

A managed pressure drilling (MPD) manifold is adapted to receive drilling mud from a wellbore during oil and gas drilling operations. The MPD manifold includes one or more drilling chokes.

Description

MANAGED PRESSURE DRILLING MANIFOLD, MODULES, AND METHODS
Cross-Reference to Related Applications This application claims the benefit of the filing date of, and priority to, U.S. Patent Application No. 62/480,158, filed March 31, 2017, the entire disclosure of which is hereby incorporated herein by reference.
This application also claims the benefit of the filing date of, and priority to, U.S. Patent Application No. 15/704,747, filed September 14, 2017, the entire disclosure of which is hereby incorporated herein by reference.
This application also claims the benefit of the filing date of, and priority to, U.S. Patent Application No. 62/576,395, filed October 24, 2017, the entire disclosure of which is hereby incorporated herein by reference.
Technical Field The present disclosure relates generally to oil and gas exploration and production operations and, more particularly, to a managed pressure drilling ("MPD") manifold used during oil and gas drilling operations.
Background An MPD system may include drilling choke(s) and a flow meter, with the drilling choke(s) and the flow meter being separate and distinct from one another. The drilling choke(s) are in fluid communication with a wellbore that traverses a subterranean formation. As a result, the drilling system may be used to control backpressure in the wellbore as part of an adaptive drilling process that allows greater control of the annular pressure profile throughout the wellbore. During such a process, the flow meter measures the flow rate of drilling mud received from the wellbore. In some cases, the configuration of the drilling choke(s) and/or the flow meter may decrease the efficiency of drilling operations, thereby presenting a problem for operators dealing with challenges such as, for example, continuous duty operations, harsh downhole environments, and multiple extended-reach lateral wells, among others. Further, the configuration of the drilling choke(s) and/or the flow meter may adversely affect the transportability and overall footprint of the drilling choke(s) and/or the flow meter at the wellsite. Finally, the separate and distinct nature of the drilling choke(s) and the flow meter can make it difficult to inspect, service, or repair the drilling choke(s) and/or the flow meter, and/or to coordinate the inspection, service, repair, or replacement of the drilling choke(s) and/or the flow meter. Therefore, what is needed is a method, apparatus, or system that addresses one or more of the foregoing issues, and/or one or more other issues.
Brief Description of the Drawings Figure 1 is a diagrammatic view of a drilling system including, among other components, an MPD manifold, according to one or more embodiments of the present disclosure.

Figure 2 is a diagrammatic view of the MPD manifold of Figure 1 in a first configuration, the MPD manifold including a choke module, a flow meter module, and a valve module, according to one or more embodiments of the present disclosure.
Figure 3 is a diagrammatic view of another embodiment of the MPD manifold of Figure 1 in a second configuration, the MPD manifold including a choke module, a flow meter module, and a valve module, according to one or more embodiments of the present disclosure.
Figure 4(a) is a perspective view of a first embodiment of the MPD manifold of any one of Figures 1-3 with the flow meter module extending in a generally horizontal orientation, the choke module of the MPD manifold including a first pair of flow blocks, and the valve module of the MPD
manifold including a second pair of flow blocks, according to one or more embodiments of the present disclosure.
Figure 4(b) is a left side elevational view of the MPD manifold of Figure 4(a), according to one or more embodiments of the present disclosure.
Figure 4(c) is a rear elevational view of the MPD manifold of Figure 4(a), according to one or more embodiments of the present disclosure.
Figure 4(d) is a right side elevational view of the MPD manifold of Figure 4(a), according to one or more embodiments of the present disclosure.
Figure 4(e) is a front elevational view of the MPD manifold of Figure 4(a), according to one or more embodiments of the present disclosure.
Figure 4(f) is a top plan view of the MPD manifold of Figure 4(a), according to one or more embodiments of the present disclosure.
Figure 5(a) is a perspective view of one of the flow blocks from the first pair of Figures 4(a)-(f), according to one or more embodiments of the present disclosure.
Figure 5(b) is a cross-sectional view of the flow block of Figure 5(a), taken along the line 5(b)-5(b) of Figure 5(a), according to one or more embodiments of the present disclosure.
Figure 6(a) is a perspective view of one of the flow blocks from the second pair of Figures 4(a)-(f), according to one or more embodiments of the present disclosure.
Figure 6(b) is a cross-sectional view of the flow block of Figure 6(a), taken along the line 6(b)-6(b) of Figure 6(a), according to one or more embodiments of the present disclosure.
Figure 7(a) is a perspective view of a second embodiment of the MPD manifold of any one of Figures 1-3 with the flow meter module extending in a generally vertical orientation, the choke module of the MPD manifold including the first pair of flow blocks, and the valve module of the MPD manifold including the second pair of flow blocks, according to one or more embodiments of the present disclosure.
Figure 7(b) is a left side elevational view of the MPD manifold of Figure 7(a), according to one or more embodiments of the present disclosure.
Figure 7(c) is a right side elevational view of the MPD manifold of Figure 7(a), according to one or more embodiments of the present disclosure.
Figure 7(d) is a top plan view of the MPD manifold of Figure 7(a), according to one or more embodiments of the present disclosure.

- 2 -Figure 8 is a flow chart illustration of a method for controlling the backpressure of a drilling mud within a wellbore, according to one or more embodiments of the present disclosure.
Figure 9 is a flow chart illustration of another method for controlling the backpressure of a drilling mud within a wellbore, according to one or more embodiments of the present disclosure.
Figure 10(a) is a perspective view of a third embodiment of the MPD manifold of any one of Figures 1-3 with the flow meter module extending in a generally horizontal orientation, the choke module of the MPD manifold including a first pair of flow blocks, and the valve module of the MPD
manifold including the second pair of flow blocks, according to one or more embodiments of the present disclosure.
Figure 10(b) is a left side elevational view of the MPD manifold of Figure 10(a), according to one or more embodiments of the present disclosure.
Figure 10(c) is a rear elevational view of the MPD manifold of Figure 10(a), according to one or more embodiments of the present disclosure.
Figure 10(d) is a right side elevational view of the MPD manifold of Figure 10(a), according to one or more embodiments of the present disclosure.
Figure 10(e) is a front elevational view of the MPD manifold of Figure 10(a), according to one or more embodiments of the present disclosure.
Figure 10(f) is a top plan view of the MPD manifold of Figure 10(a), according to one or more embodiments of the present disclosure.
Figure 11(a) is a perspective view of one of the flow blocks from the first pair of Figures 10(a)-(f), according to one or more embodiments of the present disclosure.
Figure 11(b) is a cross-sectional view of the flow block of Figure 11(a), taken along the line 11(b)-11(b) of Figure 11(a), according to one or more embodiments of the present disclosure.
Figure 12(a) is a perspective view of a fourth embodiment of the MPD manifold of any one of Figures 1-3 with the flow meter module extending in a generally vertical orientation, the choke module of the MPD manifold including the first pair of flow blocks, and the valve module of the MPD manifold including the second pair of flow blocks, according to one or more embodiments of the present disclosure.
Figure 12(b) is a left side elevational view of the MPD manifold of Figure 12(a), according to one or more embodiments of the present disclosure.
Figure 12(c) is a right side elevational view of the MPD manifold of Figure 12(a), according to one or more embodiments of the present disclosure.
Figure 12(d) is a top plan view of the MPD manifold of Figure 12(a), according to one or more embodiments of the present disclosure.
Figure 13 is a flow chart illustration of a method for controlling the backpressure of a drilling mud within a wellbore, according to one or more embodiments of the present disclosure.
Figure 14 is a flow chart illustration of another method for controlling the backpressure of a drilling mud within a wellbore, according to one or more embodiments of the present disclosure.
Figure 15 is a diagrammatic illustration of a control unit adapted to be connected to one or more components (or sub-components) of the drilling system of Figure 1, according to one or more embodiments of the present disclosure.

- 3 -Figure 16 is a diagrammatic illustration of a computing device for implementing one or more embodiments of the present disclosure.
Detailed Description In an embodiment, as illustrated in Figure 1, a drilling system is generally referred to by the .. reference numeral 10 and includes a wellhead 12, a blowout preventer ("BOP") 14, a rotating control device ("RCD") 16, a drilling tool 18, an MPD manifold 20, a mud gas separator ("MGS") 22, a vent or flare 24, a shaker 26, and a mud pump 28. The wellhead 12 is located at the top or head of an oil and gas wellbore 29 that penetrates one or more subterranean formations, and is used in oil and gas exploration and production operations such as, for example, drilling operations. The BOP 14 is operably coupled to the wellhead 12 to prevent blowout, i.e., the uncontrolled release of crude oil and/or natural gas from the wellbore 29 during drilling operations.
The drilling tool 18 is operably coupled to a drill string (not shown), and extends within the wellbore 29. The drill string extends into the wellbore 29 through the BOP 14 and the wellhead 12. Moreover, the RCD 16 is operably coupled to the BOP 14, opposite the wellhead 12, and forms a friction seal around the drill string. The MPD manifold 20 is operably coupled to, and in fluid communication with, the RCD 16.
The MGS 22 is operably coupled to, and in fluid communication with, the MPD
manifold 20. The flare 24 and the shaker 26 are both operably coupled to, and in fluid communication with, the MGS
22. The mud pump 28 is operably coupled between, and in fluid communication with, the shaker 26 and the drill string.
In operation, the drilling system 10 is used to extend the reach or penetration of the wellbore 29 into the one or more subterranean formations. To this end, the drill string is rotated and weight-on-bit is applied to the drilling tool 18, thereby causing the drilling tool 18 to rotate against the bottom of the wellbore 29. At the same time, the mud pump 28 circulates drilling fluid to the drilling tool 18, via the drill string, as indicated by the arrows 30 and 32.
The drilling fluid is discharged from the drilling tool 18 into the wellbore 29 to clear away drill cuttings from the drilling tool 18. The drill cuttings are carried back to the surface by the drilling fluid via an annulus of the wellbore 29 surrounding the drill string, as indicated by the arrow 34. The drilling fluid and the drill cuttings, in combination, are also referred to herein as "drilling mud."
As indicated by the arrow 34 in Figure 1, the drilling mud flows into the RCD
16 through the wellhead 12 and the BOP 14. The RCD 16 diverts the flow of the drilling mud to the MPD
manifold 20 while preventing, or at least reducing, communication between the annulus of the wellbore 29 and atmosphere. In this manner, the RCD 16 enables the drilling system 10 to operate as a closed-loop system. The MPD manifold 20 receives the drilling mud from the RCD 16, and is adjusted to maintain the desired backpressure within the wellbore 29, as will be discussed in further detail below. The MGS 22 receives the drilling mud from the MPD manifold 20, and captures and separates gas from the drilling mud. The captured and separated gas is sent to the flare 24 to be burnt off Alternatively, the flare 24 is omitted and the captured and separated gas is reinjected into the one or more subterranean formations. The shaker 26 receives the drilling mud from the MGS
22, and removes the drill cuttings therefrom. The mud pump 28 then recirculates the drilling fluid to the drilling tool 18, via the drill string.

- 4 -In an embodiment, as illustrated in Figure 2 with continuing reference to Figures 1, the MPD
manifold 20 includes a choke module 36, a flow meter module 38, and a valve module 40. The choke module 36 is operably coupled to, and adapted to be in fluid communication with, the flow meter module 38 via the valve module 40. The choke module 36, the flow meter module 38, and the valve module 40 are together mounted to a skid 42. In some embodiments, one or more instruments such as, for example, a temperature sensor 44, a densometer 46, and one or more pressure sensors, are operably coupled to the choke module 36. Additionally, one or more instruments such as, for example, a temperature sensor 48, a densometer 50, and one or more other pressure sensors, are operably coupled to the valve module 40. In some embodiments, one or more of the temperature .. sensors 44 and 48, one or more of the densometers 46 and 50, and pressure sensor(s) are also mounted to the skid 42. In some embodiments, one or more of the temperature sensors 44 and 48, one or more of the densometers 46 and 50, and pressure sensor(s) are part of the MPD manifold 20.
In addition to, or instead of, being mounted to the skid 42, the choke module 36, the flow meter module 38, and the valve module 40 may be freestanding on the ground or mounted to a trailer (not shown) that can be towed between operational sites.
During the operation of the drilling system 10, the valve module 40 receives the drilling mud from the RCD 16, as indicated by arrows 52 and 54. The temperature sensor 48 measures the temperature of the drilling mud immediately before the drilling mud is received by the valve module 40. In addition, the densometer 50 measures the density of the drilling mud immediately before the drilling mud is received by the valve module 40. In some embodiments, one or more pressure sensors (not shown in Figure 2) measure the pressure of the drilling mud immediately before the drilling mud is received by the valve module 40; in some embodiments, the temperature sensor 48 and/or the densometer 50 includes the one or more pressure sensors. The valve module 40 routes the drilling mud to the flow meter module 38, as indicated by arrow 56. The flow meter module 38 measures the flow rate of the drilling mud before communicating the drilling mud back to the valve module 40, as indicated by arrow 57. The valve module 40 then routes the drilling mud to the choke module 36, as indicated by arrow 58. The choke module 36 is adjusted to maintain the desired backpressure of the drilling mud within the wellbore 29. The MGS 22 receives the drilling mud from the choke module 36, as indicated by arrows 60 and 62. The temperature sensor 44 measures the temperature of the drilling mud immediately after the drilling mud is discharged from the choke module 36. In addition, the densometer 46 measures the density of the drilling mud immediately after the drilling mud is discharged from the choke module 36. In some embodiments, one or more other pressure sensors (not shown in Figure 2) measure the pressure of the drilling mud immediately after the drilling mud is discharged from the choke module 36; in some embodiments, the .. temperature sensor 44 and/or the densometer 46 includes the one or more other pressure sensors.
In some embodiments, one of which is described in further detail below with reference to Figure 3, the temperature sensor 44 and the densometer 46 are operably coupled to the valve module rather than being operably coupled to the choke module 36. Additionally, the temperature sensor 48 and the densometer 50 are operably coupled to the choke module 36 rather than being operably 40 coupled to the valve module 40. As a result, the choke module 36 receives the drilling mud from the RCD 16 and the MGS 22 receives the drilling mud from the valve module 40, as will be described

- 5 -in further detail below with reference to Figure 3. In some embodiments, pressure sensor(s) are also operably coupled to the valve module 40. In some embodiments, pressure sensor(s) are also operably coupled to the choke module 36.
In an embodiment of the choke module 36, as illustrated in Figures 4(a)-(f) with continuing reference to Figures 2 and 3, the choke module 36 includes flow blocks 64a-b, block valves 66a-e, flow blocks 68a-b, and drilling chokes 70a-b. The block valves 66a-e are each actuable between an open configuration in which fluid flow is permitted therethrough, and a closed configuration in which fluid flow therethrough is prevented, or at least reduced. In some embodiments, the block valves 66a-e are gate valves. Alternatively, one or more of the block valves 66a-e may be another type of valve such as, for example, a plug valve.
The block valve 66a is operably coupled to the flow block 64a. The flow block 68a is operably coupled to the block valve 66a via, for example, a spool 72a. The block valve 66a may provide isolation of the flow block 68a from the flow block 64a. The block valve 66b is operably coupled to the flow block 64b. The drilling choke 70a is operably coupled to the block valve 66b, via, for example, a spool 74a. The block valve 66b may provide isolation of the drilling choke 70a from the flow block 64b. The drilling choke 70a is operably coupled to the flow block 68a via, for example, a spool 76a. The block valve 66c is operably coupled to the flow block 64a adjacent the block valve 66a. The flow block 68b is operably coupled to the block valve 66c via, for example, a spool 72b. The block valve 66c may provide isolation of the flow block 68b from the flow block 64a. The block valve 66d is operably coupled to the flow block 64b adjacent the block valve 66b.
The drilling choke 70b is operably coupled to the block valve 66d via, for example, a spool 74b.
The block valve 66d may provide isolation of the drilling choke 70b from the flow block 64b. The drilling choke 70b is operably coupled to the flow block 68b via, for example, a spool 76b. The block valve 66e is operably coupled between the flow blocks 64a and 64b.
In some embodiments, each of the drilling chokes 70a and 70b is a 4-inch inner diameter (ID) choke. In some embodiments, each of the drilling chokes 70a and 70b defines an inner diameter of about 4 inches.
The choke module 36 is actuable between a backpressure control configuration and a choke bypass configuration. In the backpressure control configuration, the flow block 64b is in fluid communication with the flow block 64a via one or more of the drilling chokes 70a and/or 70b. In some embodiments, when the choke module 36 is in the backpressure control configuration, the flow block 64b is not in fluid communication with the flow block 64a via the block valve 66e (i.e., the block valve 66e is closed). During the operation of the drilling system 10, when the choke module 36 is in the backpressure control configuration, one or more of the drilling chokes 70a and/or 70b are adjusted to account for changes in the flow rate of the drilling mud so that the desired backpressure within the wellbore 29 is maintained. In the choke bypass configuration, the flow block 64b is in fluid communication with the flow block 64a via the block valve 66e. In some embodiments, when the choke module 36 is in the choke bypass configuration, the flow block 64b is not in fluid communication with the flow block 64a via the drilling chokes 70a or 70b. In some embodiments, to enable such fluid communication between the flow blocks 64a and 64b via the

- 6 -block valve 66e, the block valves 66a-d are actuated to the closed configuration and the block valve 66e is actuated to the open configuration.
In some embodiments, one or more of the drilling chokes 70a and/or 70b are manual chokes, thus enabling rig personnel to manually control backpressure within the drilling system 10 when the choke module 36 is in the backpressure control configuration. In some embodiments, one or more of the drilling chokes 70a and/or 70b are automatic chokes controlled automatically by electronic pressure monitoring equipment when the choke module 36 is in the backpressure control configuration. In some embodiments, one or more of the drilling chokes 70a and/or 70b are combination manual/automatic chokes.
In some embodiments, when the choke module 36 is in the backpressure control configuration, the flow block 64b is in fluid communication with the flow block 64a via at least the drilling choke 70a. To enable such fluid communication between the flow blocks 64a and 64b via the drilling choke 70a, the block valves 66a and 66b are actuated to the open configuration, and the block valve 66e is actuated to the closed configuration. As a result, the flow block 64b is in fluid communication with the flow block 64a via at least the block valve 66b, the spool 74a, the drilling choke 70a, the spool 76a, the flow block 68a, the spool 72a, and the block valve 66a, respectively.
In some embodiments, when the choke module 36 is in the backpressure control configuration, the flow block 64b is in fluid communication with the flow block 64a via at least the drilling choke 70b. To enable such fluid communication between the flow blocks 64a and 64b via the drilling choke 70b, the block valves 66c and 66d are actuated to the open configuration, and the block valve 66e is actuated to the closed configuration. As a result, the flow block 64b is in fluid communication with the flow block 64a via at least the block valve 66d, the spool 74b, the drilling choke 70b, the spool 76b, the flow block 68b, the spool 72b, and the block valve 66c, respectively.
In some embodiments, the flow blocks 64a and 64b are substantially identical to one another and, therefore, in connection with Figures 5(a)-(b), only the flow block 64a will be described in detail below; however, the description below applies to both of the flow blocks 64a and 64b. In an embodiment, as illustrated in Figures 5(a)-(b) with continuing reference to Figures 4(a)-(f), the flow block 64a includes ends 78a-b and sides 80a-d. In some embodiments, the ends 78a and 78b are spaced in a substantially parallel relation. In some embodiments, the sides 80a and 80b are spaced in a substantially parallel relation, each extending from the end 78a to the end 78b. In some embodiments, the sides 80c and 80d are spaced in a substantially parallel relation, each extending from the end 78a to the end 78b. In some embodiments, one of which is shown in Figures 5(a)-(b), the sides 80a and 80b are spaced in a substantially parallel relation, and the sides 80c and 80d are spaced in a substantially parallel relation. In some embodiments, the sides 80a and 80b are spaced in a substantially perpendicular relation with the sides 80c and 80d. In some embodiments, the ends 78a and 78b are spaced in a substantially perpendicular relation with the sides 80a and 80b. In some embodiments, the ends 78a and 78b are spaced in a substantially perpendicular relation with the sides 80c and 80d. In some embodiments, one of which is shown in Figures 5(a)-(b), the ends 78a and 78b are spaced in a substantially perpendicular relation with the sides 80a, 80b, 80c, and 80d.
In addition, the flow block 64a defines an internal region 82 and fluid passageways 84a-f. In some embodiments, the fluid passageway 84a extends through the end 78a of the flow block 64a

- 7 -into the internal region 82. In some embodiments, the fluid passageway 84b extends through the end 78b of the flow block 64a into the internal region 82. In some embodiments, one of which shown in Figures 5(a)-(b), the fluid passageway 84a extends through the end 78a of the flow block 64a into the internal region 82, and the fluid passageway 84b extends through the end 78b of the flow block 64a into the internal region 82. In some embodiments, the fluid passageways 84a and 84b form a continuous fluid passageway together with the internal region 82.
In some embodiments, the fluid passageway 84c extends through the side 80a of the flow block 64a into the internal region 82. In some embodiments, the fluid passageway 84d extends through the side 80b of the flow block 64a into the internal region 82. In some embodiments, one of which is shown in Figures 5(a)-(b), the fluid passageway 84c extends through the side 80a of the flow block 64a into the internal region 82, and the fluid passageway 84d extends through the side 80b of the flow block 64a into the internal region 82. In some embodiments, the fluid passageways 84c and 84d form a continuous fluid passageway together with the internal region 82. In some embodiments, one of which is shown in Figures 5(a)-(b), the fluid passageways 84e and 84f each extend through the side 80c of the flow block 64a into the internal region 82. In some embodiments, one or more of the fluid passageways 84a, 84c, or 84d are omitted from the flow block 64a, and/or one or more fluid passageways analogous to the fluid passageways 84a, 84c, or 84d of the flow block 64a are omitted from the flow block 64b.
In an embodiment of the choke module 36, as illustrated in Figures 4(a)-(f) with continuing reference to Figures 5(a)-(b), the block valve 66a is operably coupled to the side 80c of the flow block 64a and in fluid communication with the internal region 82 thereof via the fluid passageway 84e, and the block valve 66c is operably coupled to the side 80c of the flow block 64a (adjacent the block valve 66a) and in fluid communication with the internal region 82 thereof via the fluid passageway 84f The block valves 66b and 66d are operably coupled to the flow block 64b in substantially the same manner as the manner in which the block valves 66a and 66c are operably coupled to the flow block 64a. The block valve 66e is operably coupled to the side 80b of the flow block 64a and in fluid communication with the internal region 82 thereof via the fluid passageway 84d. Moreover, the block valve 66e is operably coupled to the flow block 64b in substantially the same manner as the manner in which the block valve 66e is operably coupled to the flow block 64a, except that the block valve 66e is operably coupled to a side of the flow block 64b analogous to the side 80a of the flow block 64a¨as a result, the block valve 66e is in fluid communication with an internal region of the flow block 64b via a fluid passageway analogous to the fluid passageway 84c of the flow block 64a.
In some embodiments, the operable coupling of the block valves 66a and 66c to the flow block 64a and the operable coupling of the block valves 66b and 66d to the flow block 64b reduce the number of fluid couplings, and thus potential leak paths, required to make up the choke module 36. In some embodiments, the manner in which the block valves 66a and 66c are operably coupled to the flow block 64a and the manner in which the block valves 66b and 66d are operably coupled to the flow block 64b permit the drilling chokes 70a and 70b to be operably coupled in parallel between the flow blocks 64a and 64b. In some embodiments, the spacing between the block valves 66a and 66c operably coupled to the flow block 64a and the spacing between the block valves 66b

- 8 -and 66d operably coupled to the flow block 64b permit the drilling chokes 70a and 70b to be operably coupled in parallel between the flow blocks 64a and 64b.
In an embodiment, as illustrated in Figures 4(a)-(f) with continuing reference to Figures 2 and 3, an embodiment of the valve module 40 is shown in which the valve module 40 includes flow blocks 86a-b and valves 88a-e. The valves 88a-e are each actuable between an open configuration in which fluid flow is permitted therethrough, and a closed configuration in which fluid flow therethrough is prevented, or at least reduced. In some embodiments, the valves 88a-e are gate valves. Alternatively, one or more of the valves 88a-e may be another type of valve such as, for example, a plug valve. The valve 88e is operably coupled between the flow blocks 86a and 86b.
The valve 88a is operably coupled to the flow block 86a. The valve 88b is operably coupled to the flow block 86a, opposite the valve 88a. The valve 88c is operably coupled to the flow block 86b.
The valve 88d is operably coupled to the flow block 86b, opposite the valve 88c.
The valve module 40 is actuable between a flow metering configuration and a meter bypass configuration. In the flow metering configuration, the flow blocks 86a and 86b are in fluid communication via at least the valves 88b and 88d (e.g., the valves 88b and 88d are open) and the flow meter module 38, and are not in fluid communication via the valve 88e (i.e., the valve 88e is closed). In some embodiments, when the valve module 40 is in the flow metering configuration, the valves 88a and 88e are closed and the valves 88b-d are open. Alternatively, in some embodiments, when the valve module is in the flow metering configuration, the valves 88c and 88e are closed and the valves 88a, 88b, and 88d are open. In the meter bypass configuration, the flow blocks 86a and 86b are in fluid communication via the valve 88e (i.e., the valve 88e is open), and are not in fluid communication via the valves 88b and 88d (e.g., the valves 88b and 88d are closed) and the flow meter module 38. In some embodiments, when the valve module 40 is in the meter bypass configuration, the valves 88a, 88b, and 88d are closed and the valves 88c and 88e are open.
Alternatively, in some embodiments, when the valve module 40 is in the meter bypass configuration, the valves 88b-d are closed and the valves 88a and 88e are open.
In some embodiments, the flow blocks 86a and 86b are substantially identical to one another and, therefore, in connection with Figures 6(a)-(b), only the flow block 86a will be described in detail below; however, the description below applies to both of the flow blocks 86a and 86b. In an embodiment, as illustrated in Figures 6(a)-(b) with continuing reference to Figures 4(a)-(f), the flow block 86a includes sides 90a-f. In some embodiments, the sides 90a and 90b are spaced in a substantially parallel relation. In some embodiments, the sides 90c and 90d are spaced in a substantially parallel relation, each extending from the side 90a to the side 90b. In some embodiments, the sides 90e and 90f are spaced in a substantially parallel relation, each extending from the side 90a to the side 90b. In some embodiments, one of which is shown in Figures 6(a)-(b), the sides 90c and 90d are spaced in a substantially parallel relation, and the sides 90e and 90f are spaced in a substantially parallel relation. In some embodiments, the sides 90c and 90d are spaced in a substantially perpendicular relation with the sides 90e and 90f. In some embodiments, the sides 90a and 90b are spaced in a substantially perpendicular relation with the sides 90c and 90d. In some embodiments, the sides 90a and 90b are spaced in a substantially perpendicular relation with the

- 9 -sides 90e and 90f. In some embodiments, one of which is shown in Figures 6(a)-(b), the sides 90a and 90b are spaced in a substantially perpendicular relation with the sides 90c, 90d, 90e, and 90f.
In addition, the flow block 86a defines an internal region 92 and fluid passageways 94a-e. In some embodiments, the fluid passageway 94a extends through the side 90a of the flow block 86a into the internal region 92. In some embodiments, the fluid passageway 94b extends through the side 90b of the flow block 86a into the internal region 92. In some embodiments, one of which shown in Figures 6(a)-(b), the fluid passageway 94a extends through the side 90a of the flow block 86a into the internal region 92, and the fluid passageway 94b extends through the side 90b of the flow block 86a into the internal region 92. In some embodiments, the fluid passageways 94a and 94b form a continuous fluid passageway together with the internal region 92.
In some embodiments, the fluid passageway 94c extends through the side 90c of the flow block 86a into the internal region 92. In some embodiments, the fluid passageway 94d extends through the side 90d of the flow block 86a into the internal region 92. In some embodiments, one of which is shown in Figures 6(a)-(b), the fluid passageway 94c extends through the side 90c of the flow block 86a into the internal region 92, and the fluid passageway 94d extends through the side 90d of the flow block 86a into the internal region 92. In some embodiments, the fluid passageways 94c and 94d form a continuous fluid passageway together with the internal region 92. In some embodiments, one of which is shown in Figures 6(a)-(b), the fluid passageway 94e extends through the side 90e of the flow block 86a into the internal region 92.
In an embodiment of the valve module 40, as illustrated in Figures 4(a)-(f) with continuing reference to Figures 6(a)-(b), the valve 88a is operably coupled to the side 90a of the flow block 86a and in fluid communication with the internal region 92 thereof via the fluid passageway 94a, and the valve 88b is operably coupled to the side 90b of the flow block 86a and in fluid communication with the internal region 92 thereof via the fluid passageway 94b. In some embodiments, a blind flange 95a is operably coupled to the side 90e of the flow block 86a to prevent communication between the internal region 92 and atmosphere via the fluid passageway 94e. The valves 88c and 88d are operably coupled to the flow block 86b in substantially the same manner as the manner in which the valves 88a and 88b are operably coupled to the flow block 86a. In some embodiments, a blind flange 95b is operably coupled to the flow block 86b in substantially the same manner as the manner in which the blind flange 95a is operably coupled to the flow block 86a. The valve 88e is operably coupled to the side 90d of the flow block 86a and in fluid communication with the internal region 92 thereof via the fluid passageway 94d. Moreover, the valve 88e is operably coupled to the flow block 86b in substantially the same manner as the manner in which the valve 88e is operably coupled to the flow block 86a, except that the valve 88e is operably coupled to a side of the flow block 86b analogous to the side 90c of the flow block 86a¨as a result, the valve 88e is in fluid communication with an internal region of the flow block 86b via a fluid passageway analogous to the fluid passageway 94c of the flow block 86a.
In an embodiment of the flow meter 38, as illustrated in Figures 4(a)-(f) with continuing reference to Figures 2 and 3, an embodiment of the flow meter module 38 is illustrated in which the flow meter module 38 includes a flow meter 96, flow blocks 98a-b, and spools 100a-b. In some embodiments, the flow meter 96 is a Coriolis flow meter. The spool 100a is operably coupled to,

- 10 -and in fluid communication with, the flow block 98a, and the flow meter 96 is operably coupled to, and in fluid communication with, the flow block 98b. Alternatively, the spool 100a may be operably coupled to, and in fluid communication with, the flow block 98b, and the flow meter 96 may be operably coupled to, and in fluid communication with, the flow block 98a. The spool 100b is operably coupled between, and in fluid communication with, the flow blocks 98a and 98b. In some embodiments, a measurement fitting 102a is operably coupled to the flow block 98a, opposite the spool 100a. In addition to, or instead of, the measurement fitting 102a, a measurement fitting 102b may be operably coupled to the flow block 98b, opposite the flow meter 96. In some embodiments, pressure monitoring equipment 103 (shown in Figure 4(f)) such as, for example, electronic pressure monitoring equipment (including one or more pressure sensors) for automatically controlling one or more of the drilling chokes 70a and/or 70b, is operably coupled to one or both of the measurement fittings 102a and 102b. Instead of, or in addition to, the electronic pressure monitoring equipment, the pressure monitoring equipment 103 may include analog pressure monitoring equipment (including one or more pressure sensors), which may be operably coupled to one or both of the measurement fittings 102a and 102b.
When the MPD manifold 20 is assembled, the valve module 40 is operably coupled between the choke module 36 and the flow meter module 38. More particularly, the valve 88a is operably coupled to the end 78b of the flow block 64a and in fluid communication with the internal region 82 thereof via the fluid passageway 84b, and the valve 88c is operably coupled to the flow block 64b in substantially the same manner as the manner in which the valve 88a is operably coupled to the flow block 64a. In addition, the valve 88b is operably coupled to the spool 100a, opposite the flow block 98a, and the valve 88d is operably coupled to the flow meter 96, opposite the flow block 98b. As a result, when the valve module 40 is operably coupled between the choke module 36 and the flow meter module 38, as shown in Figures 4(a)-(f), the flow meter module 38 extends in a generally horizontal orientation. In those embodiments in which the flow meter module 38 extends in the generally horizontal orientation, the MPD manifold 20 is especially well suited for use in onshore drilling operations. In some embodiments, rather than the valve 88b being operably coupled to the spool 100a and the valve 88d being operably coupled to the flow meter 96, the valve 88b is operably coupled to the flow meter 96 and the valve 88d is operably coupled to the spool 100a.
In an embodiment, as illustrated in Figures 4(a)-(f), the MPD manifold 20 further includes a flow fitting 104a operably coupled to the side 90c of the flow block 86a and in fluid communication with the internal region 92 thereof via the fluid passageway 94c, and a flow fitting 104b operably coupled to the side 80a of the flow block 64a and in fluid communication with the internal region 82 thereof via the fluid passageway 84c. In addition to, or instead of, the flow fitting 104b, the MPD
manifold 20 may include a flow fitting 106a operably coupled to the flow block 64b in substantially the same manner as the manner in which the flow fitting 104b is operably coupled to the flow block 64a, except that the flow fitting 106a is operably coupled to a side of the flow block 64b analogous to the side 80b of the flow block 64a. Moreover, in addition to, or instead of, the flow fitting 104a, the MPD manifold 20 may include a flow fitting 106b operably coupled to the flow block 86b in substantially the same manner as the manner in which the flow fitting 104a is operably coupled to

-11-the flow block 86a, except that the flow fitting 106b is operably coupled to a side of the flow block 86b analogous to the side 90d of the flow block 86a.
In those embodiments in which the MPD manifold 20 includes the flow fittings 104a and 104b, the temperature sensor 48 and the densometer 50 may be operably coupled to the valve module 40 (as shown in Figure 2) via the flow fitting 104a, and the temperature sensor 44 and the densometer 46 may be operably coupled to the choke module 36 (as shown in Figure 2) via the flow fitting 104b. In such embodiments, the flow fitting 104a is adapted to receive the drilling mud from the RCD 16 and the MGS 22 is adapted to receive the drilling mud from the flow fitting 104b. As a result, the drilling mud may be permitted to flow through the flow meter 96 before flowing through the drilling chokes 70a and/or 70b. Additionally, in those embodiments in which the MPD manifold includes the flow fittings 106a and 106b, the temperature sensor 48 and the densometer 50 may be operably coupled to the choke module 36 (as shown in Figure 3) via the flow fitting 106a, and the temperature sensor 44 and the densometer 46 may be operably coupled to the valve module 40 (as shown in Figure 3) via the flow fitting 106b. In such embodiments, the flow fitting 106a is adapted 15 to receive the drilling mud from the RCD 16 and the MGS 22 is adapted to receive the drilling mud from the flow fitting 106b, as described in further detail below with reference to Figure 3. As a result, the drilling mud may be permitted to flow through the drilling chokes 70a and/or 70b before flowing through the flow meter 96.
In some embodiments, a measurement fitting 108 is operably coupled to the flow block 64b 20 and in fluid communication with an internal region thereof via a fluid passageway analogous to the fluid passageway 84a of the flow block 64a. In addition to, or instead of, the measurement fitting 108, another measurement fitting (not shown) may be operably coupled to the end 78a of the flow block 64a and in fluid communication with the internal region 82 thereof via the fluid passageway 84a. In some embodiments, pressure monitoring equipment 107 (shown in Figure 4(a)) such as, for example, electronic pressure monitoring equipment (including one or more pressure sensors) for automatically controlling one or more of the drilling chokes 70a and/or 70b, is operably coupled to the measurement fitting 108 and/or the measurement fitting that is operably coupled to the flow block 64a. In addition to, or instead of, the electronic pressure monitoring equipment, the pressure monitoring equipment 107 may include analog pressure monitoring equipment (including one or more pressure sensors), which may be operably coupled to the measurement fitting 108 and/or the measurement fitting that is operably coupled to the flow block 64a.
In an embodiment, as illustrated in Figures 7(a)-(d) with continuing reference to Figures 4(a)-(f), the valve module 40 is configurable so that, rather than the valve 88b being operably coupled to the side 90b of the flow block 86a and in fluid communication with the internal region 92 thereof via the fluid passageway 94b, the valve 88b is operably coupled to the side 90e of the flow block 86a and in fluid communication with the internal region 92 thereof via the fluid passageway 94e. In addition, the valve 88d is operably coupled to the flow block 86b in substantially the same manner as the manner in which the valve 88b is operably coupled to the flow block 86a. As a result, when the valve module 40 is operably coupled between the choke module 36 and the flow meter module 38, as shown in Figures 7(a)-(d), the flow meter module 38 extends in a generally vertical orientation, thus significantly decreasing the overall footprint of the MPD
manifold 20. In those

- 12 -embodiments in which the flow meter module 38 extends in the generally vertical orientation, the MPD manifold 20 is especially well suited for use in offshore drilling operations. In some embodiments, the blind flange 95a is operably coupled to the side 90b of the flow block 86a to prevent communication between the internal region 92 and atmosphere via the fluid passageway 94b. In some embodiments, the blind flange 95b is operably coupled to the flow block 86b in substantially the same manner as the manner in which the blind flange 95a is operably coupled to the flow block 86a.
In an embodiment, as illustrated in Figure 3 with continuing reference to Figure 1, the MPD
manifold 20 is configurable so that, rather than being operably coupled to the choke module 36, the temperature sensor 44 and the densometer 46 are operably coupled to the valve module 40.
Additionally, the MPD manifold 20 is configurable so that, rather than being operably coupled to the valve module 40, the temperature sensor 48 and the densometer 50 are operably coupled to the choke module 36. In some embodiments, in addition to the choke module 36, the flow meter module 38, and the valve module 40 being together mounted to the skid 42, one or more of the temperature sensors 44 and 48, and the densometers 46 and 50 are also mounted to the skid 42.
During the operation of the drilling system 10, the choke module 36 receives drilling mud from the RCD 16, as indicated by arrows 110 and 112. The temperature sensor 48 measures the temperature of the drilling mud immediately before the drilling mud is received by the choke module 36. In addition, the densometer 50 measures the density of the drilling mud immediately before the drilling mud is received by the choke module 36. The choke module 36 is adjusted to maintain the desired backpressure of the drilling mud within the wellbore 29. The choke module 36 communicates the drilling mud to the valve module 40, as indicated by arrow 114. The valve module 40 routes the drilling mud from the choke module 36 to the flow meter module 38, as indicated by arrow 116.
The flow meter module 38 measures the flow rate of the drilling mud before communicating the drilling mud back to the valve module 40, as indicated by arrow 118. The MGS
22 receives the drilling mud from the valve module 40, as indicated by arrows 120 and 122. The temperature sensor 44 measures the temperature of the drilling mud immediately after the drilling mud is discharged from the valve module 40. In addition, the densometer 46 measures the density of the drilling mud immediately after the drilling mud is discharged from the valve module 40.
In some embodiments, to determine the weight of the drilling mud: the temperature of the drilling mud measured by the temperature sensor 44 is compared with the temperature of the drilling mud measured by the temperature sensor 48; the density of the drilling mud measured by the densometer 46 is compared with the density of the drilling mud measured by the densometer 50;
and/or the respective pressure(s) of the drilling mud measured by the pressure monitoring equipment 103 (shown in Figure 4(f)) operably coupled to the measurement fittings 102a and 102b, the pressure monitoring equipment 107 (shown in Figure 4(a)) operably coupled to the measurement fitting 108, pressure monitoring equipment operably coupled to another measurement fitting of the MPD manifold 20, or any combination thereof, are compared. Thus, the temperature sensors 44 and 48, the densometers 46 and 50, and/or the pressure monitoring equipment 103 and/or 107 are operable to determine whether the weight of the drilling mud is below a critical threshold. In some embodiments, in response to a determination that the weight of the drilling mud is below the critical

- 13 -threshold: the weight of the drilling fluid circulated to the drilling tool (as indicated by the arrows 30 and 32 in Figure 1) is increased, and/or the drilling chokes 70a and/or 70b are adjusted to increase the backpressure of the drilling mud within the wellbore 29. In this manner, the temperature sensors 44 and 48, the densometers 46 and 50, and/or the pressure monitoring equipment 103 and/or 107 may be used to predict and prevent well kicks during drilling operations.
In some embodiments, to determine the amount of gas entrained in the drilling mud: the temperature of the drilling mud measured by the temperature sensor 44 is compared with the temperature of the drilling mud measured by the temperature sensor 48; the density of the drilling mud measured by the densometer 46 is compared with the density of the drilling mud measured by the densometer 50; and/or the respective pressure(s) of the drilling mud measured by the pressure monitoring equipment 103, the pressure monitoring equipment 107, pressure monitoring equipment operably coupled to another measurement fitting of the MPD manifold 20, or any combination thereof, are compared. Thus, the temperature sensors 44 and 48, the densometers 46 and 50, and/or the pressure monitoring equipment 103 and/or 107 are operable to determine whether the amount of gas entrained in the drilling mud is above a critical threshold. In some embodiments, in response to a determination that the amount of gas entrained in the drilling mud is above the critical threshold:
the weight of the drilling fluid circulated to the drilling tool (as indicated by the arrows 30 and 32 in Figure 1) is increased, and/or the drilling chokes 70a and/or 70b are adjusted to increase the backpressure of the drilling mud within the wellbore 29. In this manner, the temperature sensors 44 and 48, the densometers 46 and 50, and/or the pressure monitoring equipment 103 and/or 107 may be used to predict and prevent well kicks during drilling operations.
In some embodiments, the temperature and density of the drilling mud measured before the drilling mud passes through the drilling chokes 70a and/or 70b are compared with the temperature and density of the drilling mud after the drilling mud passes through the drilling chokes 70a and/or 70b. Further, in some embodiments, the temperature and pressure of the drilling mud measured before the drilling mud passes through the drilling chokes 70a and/or 70b are compared with the temperature and pressure of the drilling mud measured after the drilling mud passes through the drilling chokes 70a and/or 70b. Further still, in some embodiments, the density and pressure of the drilling mud measured before the drilling mud passes through the drilling chokes 70a and/or 70b are .. compared with the density and pressure of the drilling mud measured after the drilling mud passes through the drilling chokes 70a and/or 70b. Finally, in some embodiments, the temperature, density, and pressure of the drilling mud measured before the drilling mud passes through the drilling chokes 70a and/or 70b are compared with the temperature, density, and pressure of the drilling mud measured after the drilling mud passes through the drilling chokes 70a and/or 70b.
In some embodiments, during the operation of the MPD manifold 20, the execution of the method 124, the execution of the method 142, or any combination thereof, drilling mud is permitted to flow through one of the drilling chokes 70a-b, and the one of the drilling chokes 70a-b is controlled in accordance with the foregoing; in some embodiments, the remaining one of the drilling chokes 70a-b is closed but is nevertheless provided for redundancy purposes such as, for example, in the event of operational problems with one or both of the one of the drilling chokes 70a-b. In some embodiments, during the operation of the MPD manifold 20, the execution of the method 124, the

- 14 -execution of the method 142, or any combination thereof, drilling mud is permitted to flow through both of the drilling chokes 70a-b, and both of the drilling chokes 70a-b are controlled in accordance with the foregoing.
In an embodiment, as illustrated in Figure 8, a method of controlling backpressure of a drilling mud within a wellbore 29 is diagrammatically illustrated and generally referred to by the reference numeral 124. The method 124 includes receiving the drilling mud from the wellbore 29 at a step 126; either: controlling, using one or more of the drilling chokes 70a and 70b, the backpressure of the drilling mud within the wellbore 29 at a step 128, the drilling chokes 70a and 70b being part of the choke module 36, or bypassing the drilling chokes 70a and 70b of the choke module 36 at a step 131; either: measuring, using the flow meter 96, a flow rate of the drilling mud received from the wellbore 29 at a step 134, the flow meter 96 being part of the flow meter module 38, or bypassing the flow meter 96 of the flow meter module 38 at a step 136;
and discharging the drilling mud at a step 138.
The drilling mud is received from the wellbore 29 at the step 126. In an embodiment of the step 126, the drilling mud is received from the wellbore 29 via the flow fitting 104a operably coupled to, and in fluid communication with, the internal region 92 of the flow block 86a via the fluid passageway 94c thereof. In another embodiment of the step 126, the drilling mud is received from the wellbore 29 via the flow fitting 106a operably coupled to the flow block 64b in substantially the same manner as the manner in which the flow fitting 104b is operably coupled to the flow block 64a, except that the flow fitting 106a is operably coupled to a side of the flow block 64b analogous to the side 80b of the flow block 64a.
In some embodiments, one or more of the drilling chokes 70a and 70b control the backpressure of the drilling mud within the wellbore 29 at the step 128. In an embodiment of the step 128, one or more of the drilling chokes 70a and 70b are used to control the backpressure of the drilling mud within the wellbore 29 by: permitting fluid flow from the flow block 64b to the flow block 64a via one or both of the following element combinations: the block valve 66b, the drilling choke 70a, and the block valve 66a; the block valve 66d, the drilling choke 70b, and the block valve 66c; and preventing, or at least reducing, fluid flow from the flow block 64b to the flow block 64a via the block valve 66e. More particularly, one or more of the drilling chokes 70a and 70b may be used to control the backpressure of the drilling mud within the wellbore 29 by actuating the block valves 66a-e so that: the block valves 66a-b are open and the block valves 66c-e are closed; the block valves 66c-d are open and the block valves 66a-b and 66e are closed; or the block valves 66a-d are open and the block valve 66e is closed.
In some embodiments, the drilling chokes 70a and 70b are bypassed at the step 131. In an embodiment of the step 131, the drilling chokes 70a and 70b of the choke module 36 are bypassed by: permitting fluid flow from the flow block 64b to the flow block 64a via the block valve 66e; and preventing, or at least reducing, fluid flow from the flow block 64b to the flow block 64a via each of the following element combinations: the block valve 66b, the drilling choke 70a, and the block valve 66a; and the block valve 66d, the drilling choke 70b, and the block valve 66c.
More particularly, the drilling chokes 70a and 70b of the choke module 36 are bypassed by actuating the block valves 66a-e so that: the block valves 66a-d are closed and the block valve 66e is open.

- 15 -In some embodiments, the flow meter 96 measures the flow rate of the drilling mud received form the wellbore 29 at the step 134. In some embodiments, to measure the flow rate of the drilling fluid at the step 134, the valve module 40 is used to communicate the drilling mud to the flow meter module 38. In an embodiment, the valve module 40 is used to communicate the drilling mud to the .. flow meter module 38 by: permitting fluid flow from the flow block 86a to the flow block 86b via the valve 88b, the flow meter 96, and the valve 88d; and preventing, or at least reducing, fluid flow from the flow block 86a to the flow block 86b via the valve 88e. More particularly, the valve module 40 may be used to communicate the drilling mud to the flow meter module 38 by actuating the valves 88a-e so that either: the valves 88b-d are open and the valves 88a and 88e are closed; or the valves 88a, 88b, and 88d are open and the valves 88c and 88e are closed.
In an embodiment of the step 134, the drilling mud flows from the valve 88b, through the spool 100a, the flow block 98a, the spool 100b, the flow block 98b, and the flow meter 96, and into the valve 88d. During the flow of the drilling mud through the flow meter 96, the flow meter 96 measures the flow rate of the drilling mud. In some embodiments, the flow meter 96 is a Coriolis flow meter.
In some embodiments, the flow meter 96 of the flow meter module 38 is bypassed at the step 136. In an embodiment of the step 136, the flow meter 96 of the flow meter module 38 is bypassed by preventing, or at least reducing, fluid flow from the flow block 86a to the flow block 86b via the valve 88b, the flow meter 96, and the valve 88d; and permitting fluid flow from the flow block 86a .. to the flow block 86b via the valve 88e. More particularly, the flow meter 96 of the flow meter module 38 may be bypassed by actuating the block valves 88a-e so that either:
the valves 88c and 88e are open and the valves 88a, 88b, and 88d are closed; or the valves 88a and 88e are open and the valves 88b-d are closed.
The method 124 includes discharging the drilling mud at the step 138. In an embodiment of the step 138, the drilling mud is discharged via either: the flow fitting 104b operably coupled to, and in fluid communication with, the internal region 82 of the flow block 64a via the fluid passageway 84c thereof; or the flow fitting 106b operably coupled to the flow block 86b in substantially the same manner as the manner in which the flow fitting 104a is operably coupled to the flow block 86a, except that the flow fitting 106b is operably coupled to a side of the flow block 86b analogous to the side 90d of the flow block 86a.
In an embodiment of the steps 126 and 138, at the step 126 the drilling mud is received from the wellbore 29 via the flow fitting 104a operably coupled to, and in fluid communication with, the internal region 92 of the flow block 86a via the fluid passageway 94c thereof, and at the step 138 the drilling mud is discharged via the flow fitting 104b operably coupled to, and in fluid communication with, the internal region 82 of the flow block 64a via the fluid passageway 84c thereof. In another embodiment of the steps 126 and 138, at the step 126 the drilling mud is received from the wellbore 29 via the flow fitting 106a operably coupled to the flow block 64b in substantially the same manner as the manner in which the flow fitting 104b is operably coupled to the flow block 64a, and at the step 138 the drilling mud is discharged via the flow fitting 106b operably coupled to the flow block 86b in substantially the same manner as the manner in which the flow fitting 104a is operably coupled to the flow block 86a.

- 16 -In various embodiments, the steps of the method 124 may be executed with different combinations of steps in different orders and/or ways. For example, an embodiment of the method 124 includes: the step 126 at which drilling mud is received from the wellbore 29 via the flow fitting 104a operably coupled to, and in fluid communication with, the internal region 92 of the flow block 86a via the fluid passageway 94c thereof during and/or after the step 126, the step 134 at which the drilling mud flows from the flow block 86a to the flow block 86b via the valve 88b, the spool 100a, the flow block 98a, the spool 100b, the flow block 98b, the flow meter 96, and the valve 88d (the valves 88a and 88e are closed); during and/or after the step 134, the step 128 at which the drilling mud flows from the flow block 86b to the flow block 64b via the valve 88c, and from the flow block 64b to the flow block 64a via one or more of the following element combinations: the block valve 66b, the drilling choke 70a, and the block valve 66a; and the block valve 66d, the drilling choke 70b, and the block valve 66c (the block valve 66e is closed); and during and/or after the step 128, the step 138 at which the drilling mud is discharged via the flow fitting 104b operably coupled to, and in fluid communication with, the internal region 82 of the flow block 64a via the fluid passageway 84c thereof.
For another example, an embodiment of the method 124 includes: the step 126 at which drilling mud is received from the wellbore 29 via the flow fitting 104a operably coupled to, and in fluid communication with, the internal region 92 of the flow block 86a via the fluid passageway 94c thereof; during and/or after the step 126, the step 136 at which the drilling mud flows from the flow block 86a to the flow block 86b via the valve 88e (the valves 88a-d are closed); during and/or after the step 136, the step 128 at which the drilling mud flows from the flow block 86b to the flow block 64b via the valve 88c, and from the flow block 64b to the flow block 64a via one or more of the following element combinations: the block valve 66b, the drilling choke 70a, and the block valve 66a; and the block valve 66d, the drilling choke 70b, and the block valve 66c (the block valve 66e is closed); and during and/or after the step 128, the step 138 at which the drilling mud is discharged via the flow fitting 104b operably coupled to, and in fluid communication with, the internal region 82 of the flow block 64a via the fluid passageway 84c thereof.
For yet another example, an embodiment of the method 124 includes: the step 126 at which drilling mud is received from the wellbore 29 via the flow fitting 104a operably coupled to, and in fluid communication with, the internal region 92 of the flow block 86a via the fluid passageway 94c thereof; during and/or after the step 126, the step 134 at which the drilling mud flows from the flow block 86a to the flow block 86b via the valve 88b, the spool 100a, the flow block 98a, the spool 100b, the flow block 98b, the flow meter 96, and the valve 88d (the valves 88a and 88e are closed);
during and/or after the step 134, the step 131 at which the drilling mud flows from the flow block 86b to the flow block 64b via the valve 88c, and from the flow block 64b to the flow block 64a via the block valve 66e (the block valves 66a-d are closed); and during and/or after the step 131, the step 138 at which the drilling mud is discharged via the flow fitting 104b operably coupled to, and in fluid communication with, the internal region 82 of the flow block 64a via the fluid passageway 84c thereof For yet another example, an embodiment of the method 124 includes: the step 126 at which drilling mud is received from the wellbore 29 via the flow fitting 104a operably coupled to, and in

- 17 -fluid communication with, the internal region 92 of the flow block 86a via the fluid passageway 94c thereof; during and/or after the step 126, the step 136 at which the drilling mud flows from the flow block 86a to the flow block 86b via the valve 88e (the valves 88a-d are closed); during and/or after the step 136, the step 131 at which the drilling mud flows from the flow block 86b to the flow block 64b via the valve 88c, and from the flow block 64b to the flow block 64a via the block valve 66e (the block valves 66a-d are closed); and during and/or after the step 131, the step 138 at which the drilling mud is discharged via the flow fitting 104b operably coupled to, and in fluid communication with, the internal region 82 of the flow block 64a via the fluid passageway 84c thereof.
For yet another example, an embodiment of the method 124 includes: the step 126 at which .. the drilling mud is received from the wellbore 29 via the flow fitting 106a operably coupled to the flow block 64b in substantially the same manner as the manner in which the flow fitting 104b is operably coupled to the flow block 64a; during and/or after the step 126, the step 128 at which the drilling mud flows from the flow block 64b to the flow block 64a via one or more of the following element combinations: the block valve 66b, the drilling choke 70a, and the block valve 66a; and the .. block valve 66d, the drilling choke 70b, and the block valve 66c (the block valve 66e is closed);
during and/or after the step 128, the step 134 at which the drilling mud flows from the flow block 64a to the flow block 86a via the valve 88a, and from the flow block 86a to the flow block 86b via the valve 88b, the spool 100a, the flow block 98a, the spool 100b, the flow block 98b, the flow meter 96, and the valve 88d (the valves 88c and 88e are closed); and during and/or after the step 134, the step 138 at which the drilling mud is discharged via the flow fitting 106b operably coupled to the flow block 86b in substantially the same manner as the manner in which the flow fitting 104a is operably coupled to the flow block 86a.
For yet another example, an embodiment of the method 124 includes: the step 126 at which the drilling mud is received from the wellbore 29 via the flow fitting 106a operably coupled to the .. flow block 64b in substantially the same manner as the manner in which the flow fitting 104b is operably coupled to the flow block 64a; during and/or after the step 126, the step 128 at which the drilling mud flows from the flow block 64b to the flow block 64a via one or more of the following element combinations: the block valve 66b, the drilling choke 70a, and the block valve 66a; and the block valve 66d, the drilling choke 70b, and the block valve 66c (the block valve 66e is closed);
.. during and/or after the step 128, the step 136 at which the drilling mud flows from the flow block 64a to the flow block 86a via the valve 88a, and from the flow block 86a to the flow block 86b via the valve 88e (the valves 88b-d are closed); and during and/or after the step 136, the step 138 at which the drilling mud is discharged via the flow fitting 106b operably coupled to the flow block 86b in substantially the same manner as the manner in which the flow fitting 104a is operably coupled to the flow block 86a.
For yet another example, an embodiment of the method 124 includes: the step 126 at which the drilling mud is received from the wellbore 29 via the flow fitting 106a operably coupled to the flow block 64b in substantially the same manner as the manner in which the flow fitting 104b is operably coupled to the flow block 64a; during and/or after the step 126, the step 131 at which the drilling mud flows from the flow block 64b to the flow block 64a via the block valve 66e (the block valves 66a-d are closed); during and/or after the step 131, the step 134 at which the drilling mud

- 18 -flows from the flow block 64a to the flow block 86a via the valve 88a, and from the flow block 86a to the flow block 86b via the valve 88b, the spool 100a, the flow block 98a, the spool 100b, the flow block 98b, the flow meter 96, and the valve 88d (the valves 88c and 88e are closed); and during and/or after the step 134, the step 138 at which the drilling mud is discharged via the flow fitting 106b operably coupled to the flow block 86b in substantially the same manner as the manner in which the flow fitting 104a is operably coupled to the flow block 86a.
Finally, for yet another example, an embodiment of the method 124 includes:
the step 126 at which the drilling mud is received from the wellbore 29 via the flow fitting 106a operably coupled to the flow block 64b in substantially the same manner as the manner in which the flow fitting 104b is operably coupled to the flow block 64a; during and/or after the step 126, the step 131 at which the drilling mud flows from the flow block 64b to the flow block 64a via the block valve 66e (the block valves 66a-d are closed); during and/or after the step 131, the step 136 at which the drilling mud flows from the flow block 64a to the flow block 86a via the valve 88a, and from the flow block 86a to the flow block 86b via the valve 88e (the valves 88b-d are closed); and during and/or after the step 136, the step 138 at which the drilling mud is discharged via the flow fitting 106b operably coupled to the flow block 86b in substantially the same manner as the manner in which the flow fitting 104a is operably coupled to the flow block 86a.
In some embodiments, the configuration of the MPD manifold 20, including the drilling chokes 70a and 70b and the flow meter 96 used to carry out the method 124, optimizes the efficiency of the drilling system 10, thereby improving the cost and effectiveness of drilling operations. Such improved efficiency benefits operators dealing with challenges such as, for example, continuous duty operations, harsh downhole environments, and multiple extended-reach lateral wells, among others. In some embodiments, the configuration of the MPD
manifold 20, including the drilling chokes 70a and 70b and the flow meter 96 used to carry out the method 124, favorably affects the size and/or weight of the MPD manifold 20, and thus the transportability and overall footprint of the MPD manifold 20 at the wellsite.
In some embodiments, the integrated nature of the drilling chokes 70a and 70b and the flow meter 96 on the MPD manifold 20 used to carry out the method 124 makes it easier to inspect, service, or repair the MPD manifold 20, thereby decreasing downtime during drilling operations. In some embodiments, the integrated nature of the drilling chokes 70a and 70b and the flow meter 96 on the MPD manifold 20 used to carry out the method 124 makes it easier to coordinate the inspection, service, repair, or replacement of components of the MPD manifold 20 such as, for example, the drilling chokes 70a and 70b and/or the flow meter 96, among other components.
In this regard, an arrow 140 in Figures 4(b), 4(d), 7(b), and 7(c) indicates the direction in which the drilling choke 70a is readily removable from the choke module 36 upon decoupling of the spools 72a and 74a from the block valves 66a and 66b, respectively, or decoupling of the flow block 68a and the drilling choke 70a from the spools 72a and 74a, respectively.
Further, the arrow 140 indicates the direction in which the drilling choke 70b is readily removable from the choke module 36 upon decoupling of the spools 72b and 74b from the block valves 66c and 66d, respectively, or decoupling of the flow block 68b and the drilling choke 70b from the spools 72b and 74b, respectively. Thus, either one of the drilling chokes 70a and 70b may be readily inspected, serviced,

- 19 -repaired, or replaced during drilling operations while the other of the drilling chokes 70a and 70b remains in service.
In an embodiment, as illustrated in Figure 9, a method of controlling backpressure of a drilling mud within a wellbore 29 is diagrammatically illustrated and generally referred to by the reference numeral 142. The method 142 includes receiving the drilling mud from the wellbore 29 at a step 144; measuring, using a first sensor, a first physical property of the drilling mud before the drilling mud flows through the drilling chokes 70a and/or 70b at a step 146;
flowing the drilling mud through the drilling chokes 70a and/or 70b at a step 148; measuring, using a second sensor, the first physical property of the drilling mud after the drilling mud flows through the drilling chokes 70a .. and/or 70b at a step 150; comparing the respective measurements of the first physical property taken by the first and second sensors at a step 152; determining, based on at least the comparison of the respective measurements of the first physical property taken by the first and second sensors, an amount of gas entrained in the drilling mud at a step 154; and adjusting the drilling chokes 70a and/or 70b, based on the determination of the amount of gas entrained in the drilling mud, to control the backpressure of the drilling mud within the wellbore 29 at a step 156. In some embodiments, when the amount of gas entrained in the drilling mud is above a critical threshold, the drilling chokes 70a and/or 70b are adjusted to increase the backpressure of the drilling mud within the wellbore 29. In some embodiments, in addition to, or instead of, determining the amount of gas entrained in the drilling mud, the step 154 includes determining, based on at least the comparison of .. the respective measurements of the first physical property taken by the first and second sensors, the weight of the drilling mud. As a result, the step 156 includes adjusting the drilling chokes 70a and/or 70b, based on the determination of the weight of the drilling mud, to control the backpressure of the drilling mud within the wellbore 29.
In an embodiment of the steps 146, 148, and 150, the first physical property is density and the first and second sensors are the densometers 46 and 50. In another embodiment of the steps 146, 148, and 150, the first physical property is temperature and the first and second sensors are the temperature sensors 44 and 48. In yet another embodiment of the steps 146, 148, and 150, the first physical property is pressure and the first and second sensors are pressure sensors operably coupled to the measurement fittings 102a, 102b, 108, and/or another measurement fitting; in some embodiments, these pressure sensors may be, may include, or may be a part of, the pressure monitoring equipment 103 and/or 107.
In some embodiments of the method 142, the steps 146, 148, and 150 further include measuring, using a third sensor, a second physical property of the drilling mud before the drilling mud flows through the drilling chokes 70a and/or 70b, measuring, using a fourth sensor, the second physical property of the drilling mud after the drilling mud flows through the drilling chokes 70a and/or 70b, and comparing the respective measurements of the second physical property taken by the third and fourth sensors. In some embodiments, determining the amount of gas entrained in the drilling mud is further based on the comparison of the respective measurements of the second physical property taken by the third and fourth sensors. In an embodiment, the first physical property is density and the first and second sensors are the densometers 46 and 50, and the second physical property is temperature and the third and fourth sensors are the temperature sensors 44 and

- 20 -48. In another embodiment, the first physical property is density and the first and second sensors are the densometers 46 and 50, and the second physical property is pressure and the third and fourth sensors are pressure sensors operably coupled to the measurement fittings 102a, 102b, 108, and/or another measurement fitting; in some embodiments, these pressure sensors may be, may include, or may be a part of, the pressure monitoring equipment 103 and/or 107. In yet another embodiment, the first physical property is temperature and the first and second sensors are the temperature sensors 44 and 48, and the second physical property is pressure and the third and fourth sensors are pressure sensors operably coupled to the measurement fittings 102a, 102b, 108, and/or another measurement fitting; in some embodiments, these pressure sensors may be, may include, or may be a part of, the .. pressure monitoring equipment 103 and/or 107.
In some embodiments of the method 142, the steps 146, 148, and 150 further include measuring, using a fifth sensor, a third physical property of the drilling mud before the drilling mud flows through the drilling chokes 70a and/or 70b, measuring, using a sixth sensor, the third physical property of the drilling mud after the drilling mud flows through the drilling chokes 70a and/or 70b, and comparing the respective measurements of the third physical property taken by the fifth and sixth sensors. In some embodiments, determining the amount of gas entrained in the drilling mud is further based on the comparison of the respective measurements of the third physical property taken by the fifth and sixth sensors. In an embodiment, the first physical property is density and the first and second sensors are densometers 46 and 50, the second physical property is temperature and the third and fourth sensors are the temperature sensors 44 and 48, and the third physical property is pressure and the fifth and sixth sensors are pressure sensors operably coupled to the measurement fittings 102a, 102b, 108, and/or another measurement fitting; in some embodiments, these pressure sensors may be, may include, or may be a part of, the pressure monitoring equipment 103 and/or 107.
In an embodiment, as illustrated in Figures 10(a)-(f), the choke module 36 is omitted from IVIPD manifold 20 and replaced with a choke module 158¨the ability of the choke module 36 to be easily replaced by, or substituted with, the choke module 158 (or vice versa) is denoted in Figures 2 and 3. The choke module 158 includes flow blocks 160a-b, block valves 162a-m, bleed valves 163a-f, flow blocks 164a-c, and drilling chokes 166a-c. The block valves 162a-m are each actuable between an open configuration in which fluid flow is permitted therethrough, and a closed configuration in which fluid flow therethrough is prevented, or at least reduced. In some embodiments, the block valves 162a-m are gate valves. Alternatively, one or more of the block valves 162a-m may be another type of valve such as, for example, a plug valve.
The block valve 162m is operably coupled between the flow blocks 160a and 160b.
The block valve 162a is operably coupled to the flow block 160a. The bleed valve 163a is operably coupled to the block valve 162a, opposite the flow block 160a. The block valve 162b is operably coupled to the bleed valve 163a, opposite the block valve 162a. The flow block 164a is operably coupled to the block valve 162b, opposite the bleed valve 163a, via, for example, a spool 168a. In combination, the bleed valve 163a and the block valves 162a and 162b may provide a type of "double block-and-bleed" isolation of the flow block 164a from the flow block 160a. For example, in some embodiments, to provide a type of "double block-and-bleed"
isolation of the flow

-21 -block 164a from the flow block 160a, both of the block valves 162a and 162b are closed, and the bleed valve 163a is opened to permit any necessary bleeding or depressurization of the fluid flow path between the block valves 162a and 162b, ensuring that the flow block 164a has been fluidically isolated from the flow block 160a. In some embodiments, in combination, the bleed valve 163a and the block valves 162a and 162b provide a type of "double block-and-bleed"
isolation of the flow block 164a from the flow block 160a and therefore, in some embodiments, this combination is especially suitable for offshore applications. The block valve 162c is operably coupled to the flow block 160b. The bleed valve 163b is operably coupled to the block valve 162c, opposite the flow block 160b. The block valve 162d is operably coupled to the bleed valve 163b, opposite the block valve 162c. The drilling choke 166a is operably coupled to the block valve 162d, opposite the bleed valve 163b, via, for example, a spool 170a. In combination, the bleed valve 163b and the block valves 162c and 162d may provide a type of "double block-and-bleed" isolation of the drilling choke 166a from the flow block 160b. For example, in some embodiments, to provide a type of "double block-and-bleed" isolation of the drilling choke 166a from the flow block 160b, both of the block valves 162c and 162d are closed, and the bleed valve 163b is opened to permit any necessary bleeding or depressurization of the fluid flow path between the block valves 162c and 162d, ensuring that the drilling choke 166a has been fluidically isolated from the flow block 160b. In some embodiments, in combination, the bleed valve 163b and the block valves 162c and 162d provide a type of "double block-and-bleed" isolation of the drilling choke 166a from the flow block 160b and therefore, in some embodiments, this combination is especially suitable for offshore applications. The drilling choke 166a is operably coupled to the flow block 164a via, for example, a spool 172a.
The block valve 162e is operably coupled to the flow block 160a adjacent the block valve 162a. The bleed valve 163c is operably coupled to the block valve 162e, opposite the flow block 160a. The block valve 162f is operably coupled to the bleed valve 163c, opposite the block valve 162e. The flow block 164b is operably coupled to the block valve 162f, opposite the bleed valve 163c, via, for example, a spool 168b. In combination, the bleed valve 163c and the block valves 162e and 162f may provide a type of "double block-and-bleed" isolation of the flow block 164b from the flow block 160a. For example, in some embodiments, to provide a type of "double block-and-bleed" isolation of the flow block 164b from the flow block 160a, both of the block valves 162e and 162f are closed, and the bleed valve 163c is opened to permit any necessary bleeding or depressurization of the fluid flow path between the block valves 162e and 162f, ensuring that the flow block 164b has been fluidically isolated from the flow block 160a. In some embodiments, in combination, the bleed valve 163c and the block valves 162e and 162f provide a type of "double block-and-bleed" isolation of the flow block 164b from the flow block 160a and therefore, in some embodiments, this combination is especially suitable for offshore applications. The block valve 162g is operably coupled to the flow block 160b adjacent the block valve 162c.
The bleed valve 163d is operably coupled to the block valve 162g, opposite the flow block 160b. The block valve 162h is operably coupled to the bleed valve 163d, opposite the block valve 162g. The drilling choke 166b is operably coupled to the block valve 162h, opposite the bleed valve 163d, via, for example, a spool 170b. In combination, the bleed valve 163d and the block valves 162g and 162h may provide

- 22 -a type of "double block-and-bleed" isolation of the drilling choke 166b from the flow block 160b.
For example, in some embodiments, to provide a type of "double block-and-bleed" isolation of the drilling choke 166b from the flow block 160b, both of the block valves 162g and 162h are closed, and the bleed valve 163d is opened to permit any necessary bleeding or depressurization of the fluid flow path between the block valves 162g and 162h, ensuring that the drilling choke 166b has been fluidically isolated from the flow block 160b. In some embodiments, in combination, the bleed valve 163d and the block valves 162g and 162h provide a type of "double block-and-bleed"
isolation of the drilling choke 166b from the flow block 160b and therefore, in some embodiments, this combination is especially suitable for offshore applications. The drilling choke 166b is operably coupled to the flow block 164b via, for example, a spool 172b.
The block valve 162i is operably coupled to the flow block 160a adjacent the block valve 162e. The bleed valve 163e is operably coupled to the block valve 162i, opposite the flow block 160a. The block valve 162j is operably coupled to the bleed valve 163e, opposite the block valve 162i. The flow block 164c is operably coupled to the block valve 162j, opposite the bleed valve 163e, via, for example, a spool 168c. In combination, the bleed valve 163e and the block valves 162i and 162j may provide a type of "double block-and-bleed" isolation of the flow block 164c from the flow block 160a. For example, in some embodiments, to provide a type of "double block-and-bleed" isolation of the flow block 164c from the flow block 160a, both of the block valves 162i and 162j are closed, and the bleed valve 163e is opened to permit any necessary bleeding or depressurization of the fluid flow path between the block valves 162i and 162j, ensuring that the flow block 164c has been fluidically isolated from the flow block 160a. In some embodiments, in combination, the bleed valve 163e and the block valves 162i and 162j provide a type of "double block-and-bleed" isolation of the flow block 164c from the flow block 160a and therefore, in some embodiments, this combination is especially suitable for offshore applications. The block valve 162k is operably coupled to the flow block 160b adjacent the block valve 162g.
The bleed valve 163f is operably coupled to the block valve 162k, opposite the flow block 160b. The block valve 1621 is operably coupled to the bleed valve 163f, opposite the block valve 162k. The drilling choke 166c is operably coupled to the block valve 1621, opposite the bleed valve 163f, via, for example, a spool 170c. In combination, the bleed valve 163f and the block valves 162k and 1621 may provide a type of "double block-and-bleed" isolation of the drilling choke 166c from the flow block 160b. For example, in some embodiments, to provide a type of "double block-and-bleed"
isolation of the drilling choke 166c from the flow block 160b, both of the block valves 162k and 1621 are closed, and the bleed valve 163f is opened to permit any necessary bleeding or depressurization of the fluid flow path between the block valves 162k and 1621, ensuring that the drilling choke 166c has been fluidically isolated from the flow block 160b. In some embodiments, in combination, the bleed valve 163f and the block valves 162k and 1621 provide a type of "double block-and-bleed" isolation of the drilling choke 166c from the flow block 160b and therefore, in some embodiments, this combination is especially suitable for offshore applications. The drilling choke 166c is operably coupled to the flow block 164c via, for example, a spool 172c.
In some embodiments, each of the bleed valves 163a-f is, includes, or is part of, a needle valve. In some embodiments, at least one of the bleed valves 163a-f is, includes, or is part of, a

- 23 -needle valve. In some embodiments, one or more of the bleed valves 163a-f is, includes, or is part of, a needle valve. In some embodiments, each of the drilling chokes 166a-c is a 4-inch inner diameter (ID) choke. In some embodiments, each of the drilling chokes 166a-c defines an inner diameter of about 4 inches.
The choke module 158 is actuable between a backpressure control configuration and a choke bypass configuration. In the backpressure control configuration, the flow block 160b is in fluid communication with the flow block 160a via one or more of the drilling chokes 166a, 166b, and/or 166c. In some embodiments, when the choke module 158 is in the backpressure control configuration, the flow block 160b is not in fluid communication with the flow block 160a via the block valve 162m (i.e., the block valve 162m is closed). During the operation of the drilling system 10, when the choke module 158 is in the backpressure control configuration, one or more of the drilling chokes 166a, 166b, and/or 166c are adjusted to account for changes in the flow rate of the drilling mud so that the desired backpressure within the wellbore 29 is maintained. In the choke bypass configuration, the flow block 160b is in fluid communication with the flow block 160a via the block valve 162m. In some embodiments, when the choke module 158 is in the choke bypass configuration, the flow block 160b is not in fluid communication with the flow block 160a via the drilling chokes 166a, 166b, or 166c. In some embodiments, to enable such fluid communication between the flow blocks 160a and 160b via the block valve 162m, the block valves 162a-1 are actuated to the closed configuration and the block valve 162m is actuated to the open configuration.
In some embodiments, one or more of the drilling chokes 166a, 166b, and/or 166c are manual chokes, thus enabling rig personnel to manually control backpressure within the drilling system 10 when the choke module 158 is in the backpressure control configuration. In some embodiments, one or more of the drilling chokes 166a, 166b, and/or 166c are automatic chokes controlled automatically by electronic pressure monitoring equipment when the choke module 158 is in the backpressure control configuration. In some embodiments, one or more of the drilling chokes 166a, 166b, and/or 166c are combination manual/automatic chokes.
In some embodiments, when the choke module 158 is in the backpressure control configuration, the flow block 160b is in fluid communication with the flow block 160a via at least the drilling choke 166a. To enable such fluid communication between the flow blocks 160a and 160b via the drilling choke 166a, the block valves 162a, 162b, 162c, and 162d are actuated to the open configuration, and the block valve 162m is actuated to the closed configuration. As a result, the flow block 160b is in fluid communication with the flow block 160a via at least the block valve 162c, the bleed valve 163a, the block valve 162d, the spool 170a, the drilling choke 166a, the spool 172a, the flow block 164a, the spool 168a, the block valve 162b, the bleed valve 163a, and the block valve 162a, respectively.
In some embodiments, when the choke module 158 is in the backpressure control configuration, the flow block 160b is in fluid communication with the flow block 160a via at least the drilling choke 166b. To enable such fluid communication between the flow blocks 160a and 160b via the drilling choke 166b, the block valves 162e, 162f, 162g, and 162h are actuated to the open configuration, and the block valve 162m is actuated to the closed configuration. As a result, the flow block 160b is in fluid communication with the flow block 160a via at least the block valve

- 24 -162g, the bleed valve 163d, the block valve 162h, the spool 170b, the drilling choke 166b, the spool 172b, the flow block 164b, the spool 168b, the block valve 162f, the bleed valve 163c, and the block valve 162e, respectively.
In some embodiments, when the choke module 158 is in the backpressure control configuration, the flow block 160b is in fluid communication with the flow block 160a via at least the drilling choke 166c. To enable such fluid communication between the flow blocks 160a and 160b via the drilling choke 166c, the block valves 162i, 162j, 162k, and 1621 are actuated to the open configuration, and the block valve 162m is actuated to the closed configuration. As a result, the flow block 160b is in fluid communication with the flow block 160a via at least the block valve 1621, the bleed valve 163f, the block valve 1621, the spool 170c, the drilling choke 166c, the spool 172c, the flow block 164c, the spool 168c, the block valve 162j, the bleed valve 163e, and the block valve 162i, respectively.
In some embodiments, the flow blocks 160a and 160b are substantially identical to one another and, therefore, in connection with Figures 11(a)-(b), only the flow block 160a will be described in detail below; however, the description below applies to both of the flow blocks 160a and 160b. In an embodiment, as illustrated in Figures 11(a)-(b) with continuing reference to Figures 10(a)-(f), the flow block 160a includes ends 174a-b and sides 176a-d. In some embodiments, the ends 174a and 174b are spaced in a substantially parallel relation. In some embodiments, the sides 176a and 176b are spaced in a substantially parallel relation, each extending from the end 174a to the end 174b. In some embodiments, the sides 176c and 176d are spaced in a substantially parallel relation, each extending from the end 174a to the end 174b. In some embodiments, one of which is shown in Figures 11(a)-(b), the sides 176a and 176b are spaced in a substantially parallel relation, and the sides 176c and 176d are spaced in a substantially parallel relation.
In some embodiments, the sides 176a and 176b are spaced in a substantially perpendicular relation with the sides 176c and 176d. In some embodiments, the ends 174a and 174b are spaced in a substantially perpendicular relation with the sides 176a and 176b. In some embodiments, the ends 174a and 174b are spaced in a substantially perpendicular relation with the sides 176c and 176d. In some embodiments, one of which is shown in Figures 11(a)-(b), the ends 174a and 174b are spaced in a substantially perpendicular relation with the sides 176a, 176b, 176c, and 176d.
In addition, the flow block 160a defines an internal region 178 and fluid passageways 180a-g. In some embodiments, the fluid passageway 180a extends through the end 174a of the flow block 160a into the internal region 178. In some embodiments, the fluid passageway 180b extends through the end 174b of the flow block 160a into the internal region 178. In some embodiments, one of which shown in Figures 11(a)-(b), the fluid passageway 180a extends through the end 174a of the flow block 160a into the internal region 178, and the fluid passageway 180b extends through the end 174b of the flow block 160a into the internal region 178. In some embodiments, the fluid passageways 180a and 180b form a continuous fluid passageway together with the internal region 178. In some embodiments, the fluid passageway 180c extends through the side 176a of the flow block 160a into the internal region 178. In some embodiments, the fluid passageway 180d extends through the side 176b of the flow block 160a into the internal region 178. In some embodiments, one of which is shown in Figures 11(a)-(b), the fluid passageway 180c extends through the side

- 25 -176a of the flow block 160a into the internal region 178, and the fluid passageway 180d extends through the side 176b of the flow block 160a into the internal region 178. In some embodiments, the fluid passageways 180c and 180d form a continuous fluid passageway together with the internal region 178. In some embodiments, one of which is shown in Figures 11(a)-(b), the fluid passageways 180e, 180f, and 180g each extend through the side 176c of the flow block 160a into the internal region 178. In some embodiments, one or more of the fluid passageways 180a, 180c, or 180d are omitted from the flow block 160a, and/or one or more fluid passageways analogous to the fluid passageways 180a, 180c, or 180d of the flow block 160a are omitted from the flow block 160b.
In an embodiment of the choke module 158, as illustrated in Figures 10(a)-(f) with continuing reference to Figures 11(a)-(b), it can be seen that the block valve 162a is operably coupled to the side 176c of the flow block 160a and in fluid communication with the internal region 178 thereof via the fluid passageway 180e, the block valve 162e is operably coupled to the side 176c of the flow block 160a (adjacent the block valve 162a) and in fluid communication with the internal region 178 thereof via the fluid passageway 180f, and the block valve 162i is operably coupled to the side 176c of the flow block 160a (adjacent the block valve 162e) and in fluid communication with the internal region 178 thereof via the fluid passageway 180g. The block valves 162c, 162g, and 162k are operably coupled to the flow block 160b in substantially the same manner as the manner in which the block valves 162a, 162e, and 162i are operably coupled to the flow block 160a.
The block valve 162m is operably coupled to the side 176b of the flow block 160a and in fluid communication with the internal region 178 thereof via the fluid passageway 180d. Moreover, the block valve 162m is operably coupled to the flow block 160b in substantially the same manner as the manner in which the block valve 162m is operably coupled to the flow block 160a, except that the block valve 162m is operably coupled to a side of the flow block 160b analogous to the side 176a of the flow block 160a¨as a result, the block valve 162m is in fluid communication with an internal region of the flow block 160b via a fluid passageway analogous to the fluid passageway 180c of the flow block 160a.
In some embodiments, the operable coupling of the block valves 162a, 162e, and 162i to the flow block 160a and the operable coupling of the block valves 162c, 162g, and 162k to the flow block 160b reduces the number of fluid couplings, and thus potential leak paths, required to make up the choke module 158. In some embodiments, the manner in which the block valves 162a, 162e, and 162i are operably coupled to the flow block 160a and the manner in which the block valves 162c, 162g, and 162k are operably coupled to the flow block 160b permit the drilling chokes 166a-c to be operably coupled in parallel between the flow blocks 160a and 160b. In some embodiments, the spacing between the block valves 162a, 162e, and 162i operably coupled to the flow block 160a and the spacing between the block valves 162c, 162g, and 162k operably coupled to the flow block 160b permit the drilling chokes 166a-c to be operably coupled in parallel between the flow blocks 160a and 160b.
When the MPD manifold 20 is assembled with the choke module 158, rather than the choke module 36, the valve module 40 is operably coupled between the choke module 158 and the flow meter module 38. More particularly, the valve 88a is operably coupled to the end 174b of the flow block 160a and in fluid communication with the internal region 178 thereof via the fluid passageway

- 26 -180b, and the valve 88c is operably coupled to the flow block 160b in substantially the same manner as the manner in which the valve 88a is operably coupled to the flow block 160a. In addition, the valve 88b is operably coupled to the spool 100a, opposite the flow block 98a, and the valve 88d is operably coupled to the flow meter 96, opposite the flow block 98b. As a result, when the valve module 40 is operably coupled between the choke module 158 and the flow meter module 38, as shown in Figures 10(a)-(f), the flow meter module 38 extends in a generally horizontal orientation.
In those embodiments in which the flow meter module 38 extends in the generally horizontal orientation, the MPD manifold 20 is especially well suited for use in onshore drilling operations. In some embodiments, rather than the valve 88b being operably coupled to the spool 100a and the valve 88d being operably coupled to the flow meter 96, the valve 88b is operably coupled to the flow meter 96 and the valve 88d is operably coupled to the spool 100a.
In an embodiment, as illustrated in Figures 10(a)-(f), the MPD manifold 20 further includes a flow fitting 182a operably coupled to the side 90c of the flow block 86a and in fluid communication with the internal region 92 thereof via the fluid passageway 94c, and a flow fitting 182b operably coupled to the side 176a of the flow block 160a and in fluid communication with the internal region 178 thereof via the fluid passageway 180c. Further, in addition to, or instead of, the flow fitting 182b, the MPD manifold 20 may include a flow fitting 184a operably coupled to the flow block 160b in substantially the same manner as the manner in which the flow fitting 182b is operably coupled to the flow block 160a, except that the flow fitting 184a is operably coupled to a side of the flow block 160b analogous to the side 176b of the flow block 160a. Finally, in addition to, or instead of, the flow fitting 182a, the MPD manifold 20 may include a flow fitting 184b operably coupled to the flow block 86b in substantially the same manner as the manner in which the flow fitting 182a is operably coupled to the flow block 86a, except that the flow fitting 184b is operably coupled to a side of the flow block 86b analogous to the side 90d of the flow block 86a.
In those embodiments in which the MPD manifold 20 includes the flow fittings 182a and 182b, the temperature sensor 48 and the densometer 50 may be operably coupled to the valve module 40 (as shown in Figure 2) via the flow fitting 182a, and the temperature sensor 44 and the densometer 46 may be operably coupled to the choke module 158 (as shown in Figure 2) via the flow fitting 182b. In such embodiments, the flow fitting 182a is adapted to receive the drilling mud .. from the RCD 16 and the MGS 22 is adapted to receive the drilling mud from the flow fitting 182b.
As a result, the drilling mud may be permitted to flow through the flow meter 96 before flowing through the drilling chokes 166a, 166b, and/or 166c. Additionally, in those embodiments in which the MPD manifold 20 includes the flow fittings 184a and 184b, the temperature sensor 48 and the densometer 50 may be operably coupled to the choke module 158 (as shown in Figure 3) via the flow fitting 184a, and the temperature sensor 44 and the densometer 46 may be operably coupled to the valve module 40 (as shown in Figure 3) via the flow fitting 184b. In such embodiments, the flow fitting 184a is adapted to receive the drilling mud from the RCD 16 and the MGS 22 is adapted to receive the drilling mud from the flow fitting 184b, as described in further detail below with reference to Figure 3. As a result, the drilling mud may be permitted to flow through the drilling chokes 166a, 166b, and/or 166c before flowing through the flow meter 96.

- 27 -In some embodiments, a measurement fitting 186 is operably coupled to the flow block 160b and in fluid communication with an internal region thereof via a fluid passageway analogous to the fluid passageway 180a of the flow block 160a. In addition to, or instead of, the measurement fitting 186, another measurement fitting (not shown) may be operably coupled to the end 174a of the flow block 160a and in fluid communication with the internal region 178 thereof via the fluid passageway 180a. In some embodiments, pressure monitoring equipment 185 (shown in Figure 10(a)) such as, for example, electronic pressure monitoring equipment (including one or more pressure sensors) for automatically controlling one or more of the drilling chokes 166a, 166b, and/or 166c, is operably coupled to the measurement fitting 186 and/or the measurement fitting that is operably coupled to the flow block 160a. In addition to, or instead of, the electronic pressure monitoring equipment, the pressure monitoring equipment 185 may include analog pressure monitoring equipment (including one or more pressure sensors), which may be operably coupled to the measurement fitting 186 and/or the measurement fitting that is operably coupled to the flow block 160a.
In an embodiment, as illustrated in Figures 12(a)-(d) with continuing reference to Figures 10(a)-(f), the valve module 40 is configurable so that, rather than the valve 88b being operably coupled to the side 90b of the flow block 86a and in fluid communication with the internal region 92 thereof via the fluid passageway 94b, the valve 88b is operably coupled to the side 90e of the flow block 86a and in fluid communication with the internal region 92 thereof via the fluid passageway 94e. In addition, the valve 88d is operably coupled to the flow block 86b in substantially the same manner as the manner in which the valve 88b is operably coupled to the flow block 86a. As a result, when the valve module 40 is operably coupled between the choke module 158 and the flow meter module 38, as shown in Figures 12(a)-(d), the flow meter module 38 extends in a generally vertical orientation, thus significantly decreasing the overall footprint of the MPD
manifold 20. In those embodiments in which the flow meter module 38 extends in the generally vertical orientation, the MPD manifold 20 is especially well suited for use in offshore drilling operations. In some embodiments, the blind flange 95a is operably coupled to the side 90b of the flow block 86a to prevent communication between the internal region 92 and atmosphere. In some embodiments, the blind flange 95b is operably coupled to the flow block 86b in substantially the same manner as the manner in which the blind flange 95a is operably coupled to the flow block 86a.
In some embodiments, to determine the weight of the drilling mud: the temperature of the drilling mud measured by the temperature sensor 44 is compared with the temperature of the drilling mud measured by the temperature sensor 48; the density of the drilling mud measured by the densometer 46 is compared with the density of the drilling mud measured by the densometer 50;
and/or the respective pressure(s) of the drilling mud measured by the pressure monitoring equipment 103 (shown in Figure 10(f)) operably coupled to the measurement fittings 102a and 102b, the pressure monitoring equipment 185 (shown in Figure 10(a)) operably coupled to the measurement fitting 186, pressure monitoring equipment operably coupled to another measurement fitting of the MPD manifold 20, or any combination thereof, are compared. Thus, the temperature sensors 44 and 48, the densometers 46 and 50, and/or the pressure monitoring equipment 103 and/or 185 are operable to determine whether the weight of the drilling mud is below a critical threshold. In some embodiments, in response to a determination that the weight of the drilling mud is below the critical

- 28 -threshold: the weight of the drilling fluid circulated to the drilling tool (as indicated by the arrows 30 and 32 in Figure 1) is increased, and/or the drilling chokes 166a, 166b, and/or 166c are adjusted to increase the backpressure of the drilling mud within the wellbore 29. In this manner, the temperature sensors 44 and 48, the densometers 46 and 50, and/or the pressure monitoring equipment 103 and/or 185 may be used to predict and prevent well kicks during drilling operations.
In some embodiments, to determine the amount of gas entrained in the drilling mud: the temperature of the drilling mud measured by the temperature sensor 44 is compared with the temperature of the drilling mud measured by the temperature sensor 48; the density of the drilling mud measured by the densometer 46 is compared with the density of the drilling mud measured by the densometer 50; and/or the respective pressure(s) of the drilling mud measured by the pressure monitoring equipment 103, the pressure monitoring equipment 185, pressure monitoring equipment operably coupled to another measurement fitting of the MPD manifold 20, or any combination thereof, are compared. Thus, the temperature sensors 44 and 48, the densometers 46 and 50, and/or the pressure monitoring equipment 103 and/or 185 are operable to determine whether the amount of gas entrained in the drilling mud is above a critical threshold. In some embodiments, in response to a determination that the amount of gas entrained in the drilling mud is above the critical threshold:
the weight of the drilling fluid circulated to the drilling tool (as indicated by the arrows 30 and 32 in Figure 1) is increased, and/or the drilling chokes 166a, 166b, and/or 166c are adjusted to increase the backpressure of the drilling mud within the wellbore 29. In this manner, the temperature sensors 44 and 48, the densometers 46 and 50, and/or the pressure monitoring equipment 103 and/or 185 may be used to predict and prevent well kicks during drilling operations.
In some embodiments, the temperature and density of the drilling mud measured before the drilling mud passes through the drilling chokes 166a, 166b, and/or 166c are compared with the temperature and density of the drilling mud after the drilling mud passes through the drilling chokes 166a, 166b, and/or 166c. Further, in some embodiments, the temperature and pressure of the drilling mud measured before the drilling mud passes through the drilling chokes 166a, 166b, and/or 166c are compared with the temperature and pressure of the drilling mud measured after the drilling mud passes through the drilling chokes 166a, 166b, and/or 166c. Further still, in some embodiments, the density and pressure of the drilling mud measured before the drilling mud passes through the drilling chokes 166a, 166b, and/or 166c are compared with the density and pressure of the drilling mud measured after the drilling mud passes through the drilling chokes 166a, 166b, and/or 166c. Finally, in some embodiments, the temperature, density, and pressure of the drilling mud measured before the drilling mud passes through the drilling chokes 166a, 166b, and/or 166c are compared with the temperature, density, and pressure of the drilling mud measured after the drilling mud passes through the drilling chokes 166a, 166b, and/or 166c.
In an embodiment, as illustrated in Figure 13, a method of controlling backpressure of a drilling mud within a wellbore 29 is diagrammatically illustrated and generally referred to by the reference numeral 188. The method 188 includes receiving the drilling mud from the wellbore 29 at a step 190; either: controlling, using one or more of the drilling chokes 166a-c, the backpressure of the drilling mud within the wellbore 29 at a step 192, the drilling chokes 166a-c being part of the choke module 158, or bypassing the drilling chokes 166a-c of the choke module 158 at a step 194;

- 29 -either: measuring, using the flow meter 96, a flow rate of the drilling mud received from the wellbore 29 at a step 196, the flow meter 96 being part of the flow meter module 38, or bypassing the flow meter 96 of the flow meter module 38 at a step 198; and discharging the drilling mud at a step 200. In some embodiments, the steps 196 and 198 of the method 188 are substantially identical to the steps 134 and 136 of the method 124; therefore, the steps 196 and 198 will not be discussed in further detail.
The drilling mud is received from the wellbore 29 at the step 190. In an embodiment of the step 190, the drilling mud is received from the wellbore 29 via the flow fitting 182a operably coupled to, and in fluid communication with, the internal region 92 of the flow block 86a via the fluid passageway 94c thereof. In another embodiment of the step 190, the drilling mud is received from the wellbore 29 via the flow fitting 184a operably coupled to the flow block 160b in substantially the same manner as the manner in which the flow fitting 182b is operably coupled to the flow block 160a, except that the flow fitting 184a is operably coupled to a side of the flow block 160b analogous to the side 176b of the flow block 160a.
In some embodiments, one or more of the drilling chokes 166a-c control the backpressure of the drilling mud within the wellbore 29 at the step 192. In an embodiment of the step 192, one or more of the drilling chokes 166a-c are used to control the backpressure of the drilling mud within the wellbore 29 by: permitting fluid flow from the flow block 160b to the flow block 160a via one or both of the following element combinations: the block valve 162c, the bleed valve 163b, the block valve 162d, the drilling choke 166a, the block valve 162b, the bleed valve 163a, and the block valve 162a; the block valve 162g, the bleed valve 163d, the block valve 162h, the drilling choke 166b, the block valve 162f, the bleed valve 163c, and the block valve 162e; and the block valve 162k, the bleed valve 163f, the block valve 1621, the drilling choke 166c, the block valve 162j, the bleed valve 163e, and the block valve 162i; and preventing, or at least reducing, fluid flow from the flow block 160b to the flow block 160a via the block valve 162e. More particularly, one or more of the drilling chokes 166a-c may be used to control the backpressure of the drilling mud within the wellbore 29 by actuating the block valves 162a-m so that: the block valves 162a-d are actuated to the open configuration and the block valves 162e-m are actuated to the closed configuration; the block valves 162e-h are actuated to the open configuration and the block valves 162a-d and 162i-m are actuated to the closed configuration; the block valves 162i-1 are actuated to the open configuration and the block valves 162a-h and 162m are actuated to the closed configuration; the block valves 162a-h are actuated to the open configuration and the block valves 162i-m are actuated to the closed configuration; the block valves 162a-d and 162i-1 are actuated to the open configuration and the block valves 162e-h and 162m are actuated to the closed configuration; the block valves 162e-1 are actuated to the open configuration and the block valves 162a-d and 162m are actuated to the closed configuration; or the block valves 162a-1 are actuated to the open configuration and the block valve 162m is actuated to the closed configuration.
In some embodiments, the drilling chokes 166a-c are bypassed at the step 194.
In an embodiment of the step 194, the drilling chokes 166a-c of the choke module 158 are bypassed by:
permitting fluid flow from the flow block 160b to the flow block 160a via the block valve 162m;
and preventing, or at least reducing, fluid flow from the flow block 160b to the flow block 160a via

- 30 -each of the following element combinations: the block valve 162c, the bleed valve 163b, the block valve 162d, the drilling choke 166a, the block valve 162b, the bleed valve 163a, and the block valve 162a; the block valve 162g, the bleed valve 163d, the block valve 162h, the drilling choke 166b, the block valve 162f, the bleed valve 163c, and the block valve 162e; and the block valve 162k, the bleed valve 163f, the block valve 1621, the drilling choke 166c, the block valve 162j, the bleed valve 163e, and the block valve 162i. More particularly, the drilling chokes 166a-c of the choke module 158 are bypassed by actuating the block valves 162a-m so that: the block valves 162a-1 are closed and the block valve 162m is open.
The method 188 includes discharging the drilling mud at the step 200. In an embodiment of the step 200, the drilling mud is discharged via either: the flow fitting 182b operably coupled to, and in fluid communication with, the internal region 178 of the flow block 160a via the fluid passageway 180c thereof; or the flow fitting 184b operably coupled to the flow block 86b in substantially the same manner as the manner in which the flow fitting 182a is operably coupled to the flow block 86a, except that the flow fitting 184b is operably coupled to a side of the flow block 86b analogous to the side 90d of the flow block 86a.
In an embodiment of the steps 190 and 200, at the step 190 the drilling mud is received from the wellbore 29 via the flow fitting 182a operably coupled to, and in fluid communication with, the internal region 92 of the flow block 86a via the fluid passageway 94c thereof, and at the step 200 the drilling mud is discharged via the flow fitting 182b operably coupled to, and in fluid communication with, the internal region 178 of the flow block 160a via the fluid passageway 180c thereof. In another embodiment of the steps 190 and 200, at the step 190 the drilling mud is received from the wellbore 29 via the flow fitting 184a operably coupled to the flow block 160b in substantially the same manner as the manner in which the flow fitting 182b is operably coupled to the flow block 160a, and at the step 200 the drilling mud is discharged via the flow fitting 184b operably coupled to the flow block 86b in substantially the same manner as the manner in which the flow fitting 182a is operably coupled to the flow block 86a.
In various embodiments, the steps of the method 188 may be executed with different combinations of steps in different orders and/or ways. For example, an embodiment of the method 188 includes: the step 190 at which drilling mud is received from the wellbore 29 via the flow fitting 182a operably coupled to, and in fluid communication with, the internal region 92 of the flow block 86a via the fluid passageway 94c thereof; during and/or after the step 190, the step 196 at which the drilling mud flows from the flow block 86a to the flow block 86b via the valve 88b, the spool 100a, the flow block 98a, the spool 100b, the flow block 98b, the flow meter 96, and the valve 88d (the valves 88a and 88e are closed); during and/or after the step 196, the step 192 at which the drilling mud flows from the flow block 86b to the flow block 160b via the valve 88c, and from the flow block 160b to the flow block 160a via one or more of the following element combinations: the block valve 162c, the bleed valve 163b, the block valve 162d, the drilling choke 166a, the block valve 162b, the bleed valve 163a, and the block valve 162a; the block valve 162g, the bleed valve 163d, the block valve 162h, the drilling choke 166b, the block valve 162f, the bleed valve 163c, and the block valve 162e; and the block valve 162k, the bleed valve 163f, the block valve 1621, the drilling choke 166c, the block valve 162j, the bleed valve 163e, and the block valve 162i (the block valve

-31-162m is closed); and during and/or after the step 192, the step 200 at which the drilling mud is discharged via the flow fitting 182b operably coupled to, and in fluid communication with, the internal region 178 of the flow block 160a via the fluid passageway 180c thereof For another example, an embodiment of the method 188 includes: the step 190 at which drilling mud is received from the wellbore 29 via the flow fitting 182a operably coupled to, and in fluid communication with, the internal region 92 of the flow block 86a via the fluid passageway 94c thereof; during and/or after the step 190, the step 198 at which the drilling mud flows from the flow block 86a to the flow block 86b via the valve 88e (the valves 88a, 88b, and 88d are closed); during and/or after the step 198, the step 192 at which the drilling mud flows from the flow block 86b to the flow block 160b via the valve 88c, and from the flow block 160b to the flow block 160a via one or more of the following element combinations: the block valve 162c, the bleed valve 163b, the block valve 162d, the drilling choke 166a, the block valve 162b, the bleed valve 163a, and the block valve 162a; the block valve 162g, the bleed valve 163d, the block valve 162h, the drilling choke 166b, the block valve 162f, the bleed valve 163c, and the block valve 162e; and the block valve 162k, the bleed valve 163f, the block valve 1621, the drilling choke 166c, the block valve 162j, the bleed valve 163e, and the block valve 162i (the block valve 162m is closed); and during and/or after the step 192, the step 200 at which the drilling mud is discharged via the flow fitting 182b operably coupled to, and in fluid communication with, the internal region 178 of the flow block 160a via the fluid passageway 180c thereof.
For yet another example, an embodiment of the method 188 includes: the step 190 at which drilling mud is received from the wellbore 29 via the flow fitting 182a operably coupled to, and in fluid communication with, the internal region 92 of the flow block 86a via the fluid passageway 94c thereof; during and/or after the step 190, the step 196 at which the drilling mud flows from the flow block 86a to the flow block 86b via the valve 88b, the spool 100a, the flow block 98a, the spool 100b, the flow block 98b, the flow meter 96, and the valve 88d (the valves 88a and 88e are closed);
during and/or after the step 196, the step 194 at which the drilling mud flows from the flow block 86b to the flow block 160b via the valve 88c, and from the flow block 160b to the flow block 160a via the block valve 162m (the block valves 162a-1 are closed); and during and/or after the step 194, the step 200 at which the drilling mud is discharged via the flow fitting 182b operably coupled to, and in fluid communication with, the internal region 178 of the flow block 160a via the fluid passageway 180c thereof.
For yet another example, an embodiment of the method 188 includes: the step 190 at which drilling mud is received from the wellbore 29 via the flow fitting 182a operably coupled to, and in fluid communication with, the internal region 92 of the flow block 86a via the fluid passageway 94c thereof; during and/or after the step 190, the step 198 at which the drilling mud flows from the flow block 86a to the flow block 86b via the valve 88e (the valves 88a, 88b, and 88d are closed); during and/or after the step 198, the step 194 at which the drilling mud flows from the flow block 86b to the flow block 160b via the valve 88c, and from the flow block 160b to the flow block 160a via the block valve 162m (the block valves 162a-1 are closed); and during and/or after the step 194, the step 200 at which the drilling mud is discharged via the flow fitting 182b operably coupled to, and in

- 32 -fluid communication with, the internal region 178 of the flow block 160a via the fluid passageway 180c thereof.
For yet another example, an embodiment of the method 188 includes: the step 190 at which the drilling mud is received from the wellbore 29 via the flow fitting 184a operably coupled to the flow block 160b in substantially the same manner as the manner in which the flow fitting 182b is operably coupled to the flow block 160a; during and/or after the step 190, the step 192 at which the drilling mud flows from the flow block 160b to the flow block 160a via one or more of the following element combinations: the block valve 162c, the bleed valve 163b, the block valve 162d, the drilling choke 166a, the block valve 162b, the bleed valve 163a, and the block valve 162a; the block valve 162g, the bleed valve 163d, the block valve 162h, the drilling choke 166b, the block valve 162f, the bleed valve 163c, and the block valve 162e; and the block valve 162k, the bleed valve 163f, the block valve 1621, the drilling choke 166c, the block valve 162j, the bleed valve 163e, and the block valve 162i (the block valve 162m is closed); during and/or after the step 192, the step 196 at which the drilling mud flows from the flow block 160a to the flow block 86a via the valve 88a, and from the flow block 86a to the flow block 86b via the valve 88b, the spool 100a, the flow block 98a, the spool 100b, the flow block 98b, the flow meter 96, and the valve 88d (the valves 88c and 88e are closed); and during and/or after the step 196, the step 200 at which the drilling mud is discharged via the flow fitting 184b operably coupled to the flow block 86b in substantially the same manner as the manner in which the flow fitting 182a is operably coupled to the flow block 86a.
For yet another example, an embodiment of the method 188 includes: the step 190 at which the drilling mud is received from the wellbore 29 via the flow fitting 184a operably coupled to the flow block 160b in substantially the same manner as the manner in which the flow fitting 182b is operably coupled to the flow block 160a; during and/or after the step 190, the step 192 at which the drilling mud flows from the flow block 160b to the flow block 160a via one or more of the following element combinations: the block valve 162c, the bleed valve 163b, the block valve 162d, the drilling choke 166a, the block valve 162b, the bleed valve 163a, and the block valve 162a; the block valve 162g, the bleed valve 163d, the block valve 162h, the drilling choke 166b, the block valve 162f, the bleed valve 163c, and the block valve 162e; and the block valve 162k, the bleed valve 163f, the block valve 1621, the drilling choke 166c, the block valve 162j, the bleed valve 163e, and the block valve 162i (the block valve 162m is closed); during and/or after the step 192, the step 198 at which the drilling mud flows from the flow block 160a to the flow block 86a via the valve 88a, and from the flow block 86a to the flow block 86b via the valve 88e (the valves 88b, 88c and 88d are closed); and during and/or after the step 198, the step 200 at which the drilling mud is discharged via the flow fitting 184b operably coupled to the flow block 86b in substantially the same manner as the manner in which the flow fitting 182a is operably coupled to the flow block 86a.
For yet another example, an embodiment of the method 188 includes: the step 190 at which the drilling mud is received from the wellbore 29 via the flow fitting 184a operably coupled to the flow block 160b in substantially the same manner as the manner in which the flow fitting 182b is operably coupled to the flow block 160a; during and/or after the step 190, the step 194 at which the drilling mud flows from the flow block 160b to the flow block 160a via the block valve 162m (the block valves 162a-1 are closed); during and/or after the step 194, the step 196 at which the drilling

- 33 -mud flows from the flow block 160a to the flow block 86a via the valve 88a, and from the flow block 86a to the flow block 86b via the valve 88b, the spool 100a, the flow block 98a, the spool 100b, the flow block 98b, the flow meter 96, and the valve 88d (the valves 88c and 88e are closed);
and during and/or after the step 196, the step 200 at which the drilling mud is discharged via the flow fitting 184b operably coupled to the flow block 86b in substantially the same manner as the manner in which the flow fitting 182a is operably coupled to the flow block 86a.
Finally, for yet another example, an embodiment of the method 188 includes:
the step 190 at which the drilling mud is received from the wellbore 29 via the flow fitting 184a operably coupled to the flow block 160b in substantially the same manner as the manner in which the flow fitting 182b is operably coupled to the flow block 160a; during and/or after the step 190, the step 194 at which the drilling mud flows from the flow block 160b to the flow block 160a via the block valve 162m (the block valves 162a-1 are closed); during and/or after the step 194, the step 198 at which the drilling mud flows from the flow block 160a to the flow block 86a via the valve 88a, and from the flow block 86a to the flow block 86b via the valve 88e (the valves 88b-d are closed); and during and/or after the step 198, the step 200 at which the drilling mud is discharged via the flow fitting 184b operably coupled to the flow block 86b in substantially the same manner as the manner in which the flow fitting 182a is operably coupled to the flow block 86a.
In some embodiments, the configuration of the MPD manifold 20, including the drilling chokes 166a-c and the flow meter 96 used to carry out the method 188, optimizes the efficiency of the drilling system 10, thereby improving the cost and effectiveness of drilling operations. Such improved efficiency benefits operators dealing with challenges such as, for example, continuous duty operations, harsh downhole environments, and multiple extended-reach lateral wells, among others. In some embodiments, the configuration of the MPD manifold 20, including the drilling chokes 166a-c and the flow meter 96 used to carry out the method 188, favorably affects the size and/or weight of the MPD manifold 20, and thus the transportability and overall footprint of the MPD manifold 20 at the wellsite.
In some embodiments, the integrated nature of the drilling chokes 166a-c and the flow meter 96 on the MPD manifold 20 used to carry out the method 188 makes it easier to inspect, service, or repair the MPD manifold 20, thereby decreasing downtime during drilling operations. In some embodiments, the integrated nature of the drilling chokes 166a-c and the flow meter 96 on the MPD
manifold 20 used to carry out the method 188 makes it easier to coordinate the inspection, service, repair, or replacement of components of the MPD manifold 20 such as, for example, the drilling chokes 166a-c and/or the flow meter 96, among other components. In this regard, an arrow 202 in Figures 10(b), 10(d), 12(b), and 12(c) indicates the direction in which the drilling choke 166a is readily removable from the choke module 158 upon decoupling of the spools 168a and 170a from the block valves 162b and 162d, respectively, or decoupling of the flow block 164a and the drilling choke 166a from the respective spools 168a and 170a.
Further, the arrow 202 indicates the direction in which the drilling choke 166b is readily removable from the choke module 158 upon decoupling of the spools 168b and 170b from the block valves 162f and 162h, respectively, or decoupling of the flow block 164b and the drilling choke 166b from the respective spools 168b and 170b. Further still, the arrow 202 indicates the direction

- 34 -in which the drilling choke 166c is readily removable from the choke module 158 upon decoupling of the spools 168c and 170c from the block valves 162j and 1621, respectively, or decoupling of the flow block 164c and the drilling choke 166c from the respective spools 168c and 170c.
Accordingly, one of the drilling chokes 166a-c may be readily inspected, serviced, repaired, or replaced during drilling operations while the other of the drilling chokes 166a-c remains in service.
In an embodiment, as illustrated in Figure 14, a method of controlling backpressure of a drilling mud within a wellbore 29 is diagrammatically illustrated and generally referred to by the reference numeral 204. The method 204 includes receiving the drilling mud from the wellbore 29 at a step 206; measuring, using a first sensor, a first physical property of the drilling mud before the drilling mud flows through the drilling chokes 166a, 166b, and/or 166c at a step 208; flowing the drilling mud through the drilling chokes 166a, 166b, and/or 166c at a step 210; measuring, using a second sensor, the first physical property of the drilling mud after the drilling mud flows through the drilling chokes 166a, 166b, and/or 166c at a step 212; comparing the respective measurements of the first physical property taken by the first and second sensors at a step 214;
determining, based on at least the comparison of the respective measurements of the first physical property taken by the first and second sensors, an amount of gas entrained in the drilling mud at a step 216; and adjusting the drilling chokes 166a, 166b, and/or 166c, based on the determination of the amount of gas entrained in the drilling mud, to control the backpressure of the drilling mud within the wellbore 29 at a step 218. In some embodiments, when the amount of gas entrained in the drilling mud is above a critical threshold, the drilling chokes 166a, 166b, and/or 166c are adjusted to increase the backpressure of the drilling mud within the wellbore 29. In some embodiments, in addition to, or instead of, determining the amount of gas entrained in the drilling mud, the step 216 includes determining, based on at least the comparison of the respective measurements of the first physical property taken by the first and second sensors, the weight of the drilling mud. As a result, the step 218 includes adjusting the drilling chokes 166a, 166b, and/or 166c, based on the determination of the weight of the drilling mud, to control the backpressure of the drilling mud within the wellbore 29.
In an embodiment of the steps 208, 210, and 212, the first physical property is density and the first and second sensors are the densometers 46 and 50. In another embodiment of the steps 208, 210, and 212, the first physical property is temperature and the first and second sensors are temperature sensors 44 and 48. In yet another embodiment of the steps 208, 210, and 212, the first physical property is pressure and the first and second sensors are pressure sensors operably coupled to the measurement fittings 102a, 102b, 186, and/or another measurement fitting; in some embodiments, these pressure sensors may be, may include, or may be a part of, the pressure monitoring equipment 103 and/or 185.
In some embodiments of the method 204, the steps 208, 210, and 212 further include measuring, using a third sensor, a second physical property of the drilling mud before the drilling mud flows through the drilling chokes 166a, 166b, and/or 166c, measuring, using a fourth sensor, the second physical property of the drilling mud after the drilling mud flows through the drilling chokes 166a, 166b, and/or 166c, and comparing the respective measurements of the second physical property taken by the third and fourth sensors. In some embodiments, determining the amount of gas entrained in the drilling mud is further based on the comparison of the respective measurements

- 35 -of the second physical property taken by the third and fourth sensors. In an embodiment, the first physical property is density and the first and second sensors are the densometers 46 and 50, and the second physical property is temperature and the third and fourth sensors are the temperature sensors 44 and 48. In another embodiment, the first physical property is density and the first and second sensors are the densometers 46 and 50, and the second physical property is pressure and the third and fourth sensors are pressure sensors operably coupled to the measurement fittings 102a, 102b, 186, and/or another measurement fitting; in some embodiments, these pressure sensors may be, may include, or may be a part of, the pressure monitoring equipment 103 and/or 185. In yet another embodiment, the first physical property is temperature and the first and second sensors are the temperature sensors 44 and 48, and the second physical property is pressure and the third and fourth sensors are pressure sensors operably coupled to the measurement fittings 102a, 102b, 186, and/or another measurement fitting.
In some embodiments of the method 204, the steps 208, 210, and 212 further include measuring, using a fifth sensor, a third physical property of the drilling mud before the drilling mud flows through the drilling chokes 166a, 166b, and/or 166c, measuring, using a sixth sensor, the third physical property of the drilling mud after the drilling mud flows through the drilling chokes 166a, 166b, and/or 166c, and comparing the respective measurements of the third physical property taken by the fifth and sixth sensors. In some embodiments, determining the amount of gas entrained in the drilling mud is further based on the comparison of the respective measurements of the third physical property taken by the fifth and sixth sensors. In an embodiment, the first physical property is density and the first and second sensors are densometers 46 and 50, the second physical property is temperature and the third and fourth sensors are the temperature sensors 44 and 48, and the third physical property is pressure and the fifth and sixth sensors are pressure sensors operably coupled to the measurement fittings 102a, 102b, 186, and/or another measurement fitting;
in some embodiments, these pressure sensors may be, may include, or may be a part of, the pressure monitoring equipment 103 and/or 185.
In some embodiments, during the operation of the MPD manifold 20, the execution of the method 188, the execution of the method 204, or any combination thereof, drilling mud is permitted to flow through two of the drilling chokes 166a-c, and the two of the drilling chokes 166a-c are controlled in accordance with the foregoing; in some embodiments, the remaining one of the drilling chokes 166a-c is closed but is nevertheless provided for redundancy purposes such as, for example, in the event of operational problems with one or both of the two of the drilling chokes 166a-c. In some embodiments, during the operation of the MPD manifold 20, the execution of the method 188, the execution of the method 204, or any combination thereof, drilling mud is permitted to flow through all three of the drilling chokes 166a-c, and all three of the drilling chokes 166a-c are controlled in accordance with the foregoing. In some embodiments, the above-described "double block-and-bleed" functionality provided, in part, by the bleed valves 163a-f, as well as the flow capacity provided by the use of at least two of the drilling chokes 166a-c, make the choke module 158 especially suitable for offshore applications. In some embodiments, the above-described "double block-and-bleed" functionality provided, in part, by the bleed valves 163a-f, as well as the

- 36 -flow capacity provided by the use of all of three of the drilling chokes 166a-c, make the choke module 158 especially suitable for offshore applications.
In an embodiment, as illustrated in Figure 15, a control unit is diagrammatically illustrated and generally referred to by the reference numeral 220-the control unit 220 includes a processor 222 and a non-transitory computer readable medium 224 operably coupled thereto, a plurality of instructions being stored on the non-transitory computer readable medium 224, the instructions being accessible to, and executable by, the processor 222. In some embodiments, as illustrated in Figures 4(a)-(c), (e), and (f), the control unit 220 is in communication with the drilling chokes 70a and/or 70b. In those embodiments in which the choke module 36 is omitted and replaced with the choke module 158, instead of being in communication with the drilling chokes 70a and/or 70b, the control unit 220 may be in communication with the drilling chokes 166a, 166b, and/or 166c, as illustrated in Figures 10(a)-(c), (e), and (f).
In some embodiments, as illustrated in Figures 2 and 3, the control unit 220 is also in communication with the flow meter module 38 and, therefore, the control unit 220 may communicate control signals to the drilling chokes 70a and/or 70b (or the drilling chokes 166a, 166b, and/or 166c) based on measurement data received from the flow meter module 38. In some embodiments, as illustrated in Figures 2 and 3, the control unit 220 is also in communication with the temperature sensors 44 and 48 and, therefore, the control unit 220 may communicate control signals to the drilling chokes 70a and/or 70b (or the drilling chokes 166a, 166b, and/or 166c) based on measurement data received from the temperature sensors 44 and 48. In some embodiments, as illustrated in Figures 2 and 3, the control unit 220 is also in communication with the densometers 46 and 50 and, therefore, the control unit 220 may communicate control signals to the drilling chokes 70a and/or 70b (or the drilling chokes 166a, 166b, and/or 166c) based on measurement data received from the densometers 46 and 50. In some embodiments, the control unit 220 is also in communication with pressure sensors operably coupled to the measurement fittings 102a, 102b, 108, 186 and/or another measurement fitting, and, therefore, the control unit 220 may communicate control signals to the drilling chokes 70a and/or 70b (or the drilling chokes 166a, 166b, and/or 166c) based on measurement data received from the pressure sensors; in some embodiments, these pressure sensors may be, may include, or may be part of, the pressure monitoring equipment 103, 107, and/or 185. Finally, in some embodiments, the control unit 220 is also in communication with one or more other sensors associated with the drilling system 10 such as, for example, one or more sensors associated with the drilling tool 18, the wellhead 12, the BOP 14, the RCD 16, the MGS 22, the flare 24, the shaker 26, and/or the mud pump 28; therefore, the control unit 220 may communicate control signals to the drilling chokes 70a and/or 70b (or the drilling chokes 166a, 166b, and/or 166c) based on measurement data received from the one or more sensors.
In some embodiments, a plurality of instructions, or computer program(s), are stored on a non-transitory computer readable medium, the instructions or computer program(s) being accessible to, and executable by, one or more processors. In some embodiments, the one or more processors execute the plurality of instructions (or computer program(s)) to operate in whole or in part the above-described embodiments. In some embodiments, the one or more processors are part of the control unit 220, one or more other computing devices, or any combination thereof. In some

- 37 -embodiments, the non-transitory computer readable medium is part of the control unit 220, one or more other computing devices, or any combination thereof.
In an embodiment, as illustrated in Figure 16, a computing device 1000 for implementing one or more embodiments of one or more of the above-described networks, elements, methods and/or steps, and/or any combination thereof, is depicted. The computing device 1000 includes a microprocessor 1000a, an input device 1000b, a storage device 1000c, a video controller 1000d, a system memory 1000e, a display 1000f, and a communication device 1000g all interconnected by one or more buses 1000h. In some embodiments, the storage device 1000c may include a floppy drive, hard drive, CD-ROM, optical drive, any other form of storage device and/or any combination thereof. In some embodiments, the storage device 1000c may include, and/or be capable of receiving, a floppy disk, CD-ROM, DVD-ROM, or any other form of computer-readable medium that may contain executable instructions. In some embodiments, the communication device 1000g may include a modem, network card, or any other device to enable the computing device to communicate with other computing devices. In some embodiments, any computing device represents a plurality of interconnected (whether by intranet or Internet) computer systems, including without limitation, personal computers, mainframes, PDAs, smartphones and cell phones.
In some embodiments, one or more of the components of the above-described embodiments include at least the computing device 1000 and/or components thereof, and/or one or more computing devices that are substantially similar to the computing device 1000 and/or components thereof In some embodiments, one or more of the above-described components of the computing device 1000 include respective pluralities of same components.
In some embodiments, a computer system typically includes at least hardware capable of executing machine readable instructions, as well as the software for executing acts (typically machine-readable instructions) that produce a desired result. In some embodiments, a computer system may include hybrids of hardware and software, as well as computer sub-systems.
In some embodiments, hardware generally includes at least processor-capable platforms, such as client-machines (also known as personal computers or servers), and hand-held processing devices (such as smart phones, tablet computers, personal digital assistants (PDAs), or personal computing devices (PCDs), for example). In some embodiments, hardware may include any physical device that is capable of storing machine-readable instructions, such as memory or other data storage devices. In some embodiments, other forms of hardware include hardware sub-systems, including transfer devices such as modems, modem cards, ports, and port cards, for example.
In some embodiments, software includes any machine code stored in any memory medium, such as RAM or ROM, and machine code stored on other devices (such as floppy disks, flash memory, or a CD ROM, for example). In some embodiments, software may include source or object code. In some embodiments, software encompasses any set of instructions capable of being executed on a computing device such as, for example, on a client machine or server.
In some embodiments, combinations of software and hardware could also be used for providing enhanced functionality and performance for certain embodiments of the present disclosure. In an embodiment, software functions may be directly manufactured into a silicon chip.

- 38 -Accordingly, it should be understood that combinations of hardware and software are also included within the definition of a computer system and are thus envisioned by the present disclosure as possible equivalent structures and equivalent methods.
In some embodiments, computer readable mediums include, for example, passive data storage, such as a random access memory (RAM) as well as semi-permanent data storage such as a compact disk read only memory (CD-ROM). One or more embodiments of the present disclosure may be embodied in the RAM of a computer to transform a standard computer into a new specific computing machine. In some embodiments, data structures are defined organizations of data that may enable an embodiment of the present disclosure. In an embodiment, a data structure may provide an organization of data, or an organization of executable code.
In some embodiments, any networks and/or one or more portions thereof, may be designed to work on any specific architecture. In an embodiment, one or more portions of any networks may be executed on a single computer, local area networks, client-server networks, wide area networks, internets, hand-held and other portable and wireless devices and networks.
In some embodiments, a database may be any standard or proprietary database software. In some embodiments, the database may have fields, records, data, and other database elements that may be associated through database specific software. In some embodiments, data may be mapped.
In some embodiments, mapping is the process of associating one data entry with another data entry.
In an embodiment, the data contained in the location of a character file can be mapped to a field in a second table. In some embodiments, the physical location of the database is not limiting, and the database may be distributed. In an embodiment, the database may exist remotely from the server, and run on a separate platform. In an embodiment, the database may be accessible across the Internet. In some embodiments, more than one database may be implemented.
In some embodiments, a plurality of instructions stored on a non-transitory computer readable medium may be executed by one or more processors to cause the one or more processors to carry out or implement in whole or in part the above-described operation of each of the above-described embodiments of the drilling system 10, the MPD manifold 20, the method 124, the method 142, the method 188, the method 204, and/or any combination thereof. In some embodiments, such a processor may include one or more of the microprocessor 1000a, the processor 222, and/or any combination thereof, and such a non-transitory computer readable medium may include the computer readable medium 224 and/or may be distributed among one or more components of the drilling system 10 and/or the MPD manifold 20. In some embodiments, such a processor may execute the plurality of instructions in connection with a virtual computer system. In some embodiments, such a plurality of instructions may communicate directly with the one or more processors, and/or may interact with one or more operating systems, middleware, firmware, other applications, and/or any combination thereof, to cause the one or more processors to execute the instructions.
In a first aspect, the present disclosure introduces a managed pressure drilling ("MPD") manifold adapted to receive drilling mud from a wellbore, the MPD manifold including: a first module including one or more drilling chokes; a second module including a flow meter; and a third module including first and second flow blocks operably coupled in parallel between the first and

- 39 -second modules; wherein the one or more drilling chokes are adapted to control backpressure of the drilling mud within the wellbore; and wherein the flow meter is adapted to measure a flow rate of the drilling mud received from the wellbore. In an embodiment, the third module further includes: a first valve operably coupled between, and in fluid communication with, the first flow block and the first module; a second valve operably coupled between, and in fluid communication with, the first flow block and the second module; a third valve operably coupled between, and in fluid communication with, the second flow block and the first module; and a fourth valve operably coupled between, and in fluid communication with, the second flow block and the second module.
In an embodiment, the third module further includes a fifth valve operably coupled between, and in fluid communication with, the first and second flow blocks. In an embodiment, the third module is actuable between: a first configuration in which fluid flow is permitted from the first flow block to the second flow block via the second valve, the flow meter, and the fourth valve, and fluid flow is prevented, or at least reduced, from the first flow block to the second flow block via the fifth valve;
and a second configuration in which fluid flow is prevented, or at least reduced, from the first flow block to the second flow block via the second valve, the flow meter, and the fourth valve, and fluid flow is permitted from the first flow block to the second flow block via the fifth valve. In an embodiment, in the first configuration, the first, second, third, fourth, and fifth valves are actuated so that either: the second, third, and fourth valves are open and the first and fifth valves are closed, or the first, second, and fourth valves are open and the third and fifth valves are closed; and wherein, in the second configuration, the first, second, third, fourth, and fifth valves are actuated so that either:
the third and fifth valves are open and the first, second, and fourth valves are closed, or the first and fifth valves are open and the second, third, and fourth valves are closed. In an embodiment, the first and second fluid passageways of the first flow block are generally coaxial, and the first and second fluid passageways of the second flow block are generally coaxial, so that the second module, including the flow meter, extends in a generally horizontal orientation. In an embodiment, the first and second fluid passageways of the first flow block define generally perpendicular axes, and the first and second fluid passageways of the second flow block define generally perpendicular axes, so that the second module, including the flow meter, extends in a generally vertical orientation. In an embodiment, the first and second flow blocks each include first, second, third, fourth, fifth, and sixth sides, the third, fourth, fifth, and sixth sides extending between the first and second sides, the first, third, and fourth fluid passageways extending through the first, third, and fourth sides, respectively, and the second fluid passageway extending through either the second side or the fifth side. In an embodiment, the second module further includes third and fourth flow blocks, and first and second spools, the first spool being operably coupled to, and in fluid communication with, the third flow block, the second spool being operably coupled between, and in fluid communication with, the third and fourth flow blocks, and the flow meter being operably coupled to, and in fluid communication with, the fourth flow block.
In a second aspect, the present disclosure also introduces a managed pressure drilling ("MPD") manifold adapted to receive drilling mud from a wellbore, the MPD
manifold including: a first module including one or more drilling chokes; a second module including a flow meter; and a third module operably coupled between, and in fluid communication with, the first and second

- 40 -modules, the third module being configured to support the second module in either: a generally horizontal orientation; or a generally vertical orientation; wherein the one or more drilling chokes are adapted to control backpressure of the drilling mud within the wellbore;
and wherein the flow meter is adapted to measure a flow rate of the drilling mud received from the wellbore. In an embodiment, the first and second modules are together mounted to either a skid or a trailer so that, when so mounted, the first and second modules are together towable between operational sites. In an embodiment, the third module includes first and second flow blocks operably coupled in parallel between the first and second modules, the first and second flow blocks each defining an internal region and first, second, third, fourth, and fifth fluid passageways extending into the internal region.
In an embodiment, when the third module supports the second module in the generally horizontal orientation: the first module is operably coupled to, and in fluid communication with, the internal region of the first flow block via the first fluid passageway thereof, and the second module is operably coupled to, and in fluid communication with, the internal region of the first flow block via the second fluid passageway thereof; and the first module is operably coupled to, and in fluid communication with, the internal region of the second flow block via the first fluid passageway thereof, and the second module is operably coupled to, and in fluid communication with, the internal region of the second flow block via the second fluid passageway thereof In an embodiment, when the third module supports the second module in the generally vertical orientation: the first module is operably coupled to, and in fluid communication with, the internal region of the first flow block via the first fluid passageway thereof, and the second module is operably coupled to, and in fluid communication with, the internal region of the first flow block via the fifth fluid passageway thereof; and the first module is operably coupled to, and in fluid communication with, the internal region of the second flow block via the first fluid passageway thereof, and the second module is operably coupled to, and in fluid communication with, the internal region of the second flow block via the fifth fluid passageway thereof. In an embodiment, the first and second flow blocks each include first, second, third, fourth, fifth, and sixth sides, the third, fourth, fifth, and sixth sides extending between the first and second sides, and the first, second, third, fourth, and fifth fluid passageways extending through the first, second, third, fourth, and fifth sides. In an embodiment, the third module further includes first, second, third, fourth, and fifth valves, the first and second valves being operably coupled to, and in fluid communication with, the first flow block and the respective first and second modules, the third and fourth valves being operably coupled to, and in fluid communication with, the second flow block and the respective first and second modules, and the fifth valve being operably coupled between, and in fluid communication with, the first and second flow blocks. In an embodiment, the second module further includes first and second flow blocks, and first and second spools, the first spool being operably coupled to, and in fluid communication with, the first flow block, the second spool being operably coupled between, and in fluid communication with, the first and second flow blocks, and the flow meter being operably coupled to, and in fluid communication with, the second flow block.
In a third aspect, the present disclosure also introduces a managed pressure drilling ("MPD") manifold adapted to receive drilling mud from a wellbore, the MPD manifold including: a first flow block into which the drilling mud is adapted to flow from the wellbore; a second flow block into

-41 -which the drilling mud is adapted to flow from the first flow block; a first valve operably coupled to the first and second flow blocks; and a choke module including a first drilling choke, the choke module being actuable between: a backpressure control configuration in which:
the first drilling choke is in fluid communication with the first flow block to control backpressure of the drilling mud within the wellbore; the second flow block is in fluid communication with the first flow block via the first drilling choke; and the second flow block is not in fluid communication with the first flow block via the first valve; and a choke bypass configuration in which: the first drilling choke is not in fluid communication with the first flow block; the second flow block is not in fluid communication with the first flow block via the first drilling choke; and the second flow block is in fluid communication with the first flow block via the first valve. In an embodiment, the MPD manifold further includes a valve module operably coupled to the choke module, the valve module including a second valve; and a flow meter module operably coupled to the valve module, the flow meter module including a flow meter; wherein the valve module is actuable between: a flow metering configuration in which: the second flow block is in fluid communication with the first flow block via the flow meter; and the second flow block is not in fluid communication with the first flow block via the second valve; and a meter bypass configuration in which: the second flow block is not in fluid communication with the first flow block via the flow meter; and the second flow block is in fluid communication with the first flow block via the second valve. In an embodiment, the choke module further includes a second drilling choke; and wherein the second flow block is adapted to be in fluid communication with the first flow block via one or both of the first drilling choke and the second drilling choke. In an embodiment, the valve module includes either the first flow block or the second flow block. In an embodiment, the choke module includes the first flow block and the valve module includes the second flow block. In an embodiment, the choke module includes the second flow block and the valve module includes the first flow block. In an embodiment, the flow meter is a Coriolis flow meter. In an embodiment, the choke module includes the first valve. In an embodiment, the choke module includes either the first flow block or the second flow block. In an embodiment, the choke module includes the first valve, the first flow block, and the second flow block.
In a fourth aspect, the present disclosure introduces a choke module adapted to receive drilling mud from a wellbore, the choke module including first and second fluid blocks; and first and second drilling chokes operably coupled in parallel between the first and second fluid blocks;
wherein each of the first and second drilling chokes is adapted to control a backpressure of the drilling mud within the wellbore. In an embodiment, the choke module further includes first, second, third, and fourth valves, the first and second valves being operably coupled to, and in fluid communication with, the first fluid block, the third and fourth valves being operably coupled to, and in fluid communication with, the second fluid block, the first drilling choke being operably coupled between, and in fluid communication with, the first and third valves, and the second drilling choke being operably coupled between, and in fluid communication with, the second and fourth valves. In an embodiment, the choke module further includes a fifth valve operably coupled between, and in fluid communication with, the first and second fluid blocks. In an embodiment, the choke module is actuable between a first configuration in which fluid flow is permitted from the first fluid block to

- 42 -the second fluid block via one or both of the following element combinations:
the first valve, the first drilling choke, and the third valve, and the second valve, the second drilling choke, and the fourth valve; and fluid flow is prevented, or at least reduced, from the first fluid block to the second fluid block via the fifth valve; and a second configuration in which fluid flow is permitted from the first fluid block to the second fluid block via the fifth valve; and fluid flow is prevented, or at least reduced, from the first fluid block to the second fluid block via each of the following element combinations: the first valve, the first drilling choke, and the third valve, and the second valve, the second drilling choke, and the fourth valve. In an embodiment, when the choke module is in the first configuration, the first, second, third, fourth, and fifth valves are actuated so that either: the first and third valves are open and the second, fourth, and fifth valves are closed, the second and fourth valves are open and the first, third, and fifth valves are closed, or the first, second, third, and fourth valves are open and the fifth valve is closed; and, when the choke module is in the second configuration, the first, second, third, fourth, and fifth valves are actuated so that the first, second, third, and fourth valves are closed and the fifth valve is open. In an embodiment, the first and second fluid blocks each define an internal region and first, second, third, and fourth fluid passageways extending into the internal region. In an embodiment, the first, second, and fifth valves are in fluid communication with the internal region of the first fluid block via the respective first, second, and third fluid passageways thereof; and the third, fourth, and fifth valves are in fluid communication with the internal region of the second fluid block via the respective first, second, and fourth fluid passageways thereof In an embodiment, the first and second fluid blocks each include first and second ends, and first, second, third, and fourth sides extending between the first and second ends, the first and second fluid passageways extending through the first side, and the third and fourth fluid passageways extending through the second and third sides, respectively.
In a fifth aspect, the present disclosure introduces a method of controlling backpressure of a drilling mud within a wellbore, the method including receiving the drilling mud from the wellbore;
either: controlling, using first and/or second drilling chokes, the backpressure of the drilling mud within the wellbore, the first and second drilling chokes being part of a first module, the first module further including first and second fluid blocks between which the first and second drilling chokes are operably coupled in parallel, or bypassing the first and second drilling chokes of the first module;
and discharging the drilling mud. In an embodiment, the first module further includes first, second, third, and fourth valves, the first and second valves being operably coupled to, and in fluid communication with, the first fluid block, the third and fourth valves being operably coupled to, and in fluid communication with, the second fluid block, the first drilling choke being operably coupled between, and in fluid communication with, the first and third valves, and the second drilling choke being operably coupled between, and in fluid communication with, the second and fourth valves. In an embodiment, the first module further includes a fifth valve operably coupled between, and in fluid communication with, the first and second fluid blocks. In an embodiment, controlling, using the first and/or second drilling chokes, the backpressure of the drilling mud within the wellbore includes permitting fluid flow from the first fluid block to the second fluid block via one or both of the following element combinations: the first valve, the first drilling choke, and the third valve, and the second valve, the second drilling choke, and the fourth valve; and preventing, or at least

- 43 -reducing, fluid flow from the first fluid block to the second fluid block via the fifth valve; and bypassing the first and second drilling chokes of the first module includes permitting fluid flow from the first fluid block to the second fluid block via the fifth valve; and preventing, or at least reducing, fluid flow from the first fluid block to the second fluid block via each of the following element .. combinations: the first valve, the first drilling choke, and the third valve, and the second valve, the second drilling choke, and the fourth valve. In an embodiment, controlling, using the first and/or second drilling chokes, the backpressure of the drilling mud within the wellbore includes actuating the first, second, third, fourth, and fifth valves so that: the first and third valves are open and the second, fourth, and fifth valves are closed, the second and fourth valves are open and the first, third, .. and fifth valves are closed, or the first, second, third, and fourth valves are open and the fifth valve is closed; and bypassing the first and second drilling chokes of the first module includes actuating the first, second, third, fourth, and fifth valves so that the first, second, third, and fourth valves are closed and the fifth valve is open. In an embodiment, the first and second fluid blocks each define an internal region and first, second, third, and fourth fluid passageways extending into the internal -- region. In an embodiment, the first, second, and fifth valves are in fluid communication with the internal region of the first fluid block via the respective first, second, and third fluid passageways thereof; and the third, fourth, and fifth valves are in fluid communication with the internal region of the second fluid block via the respective first, second, and fourth fluid passageways thereof. In an embodiment, the first and second fluid blocks each include first and second ends, and first, second, -- third, and fourth sides extending between the first and second ends, the first and second fluid passageways extending through the first side, and the third and fourth fluid passageways extending through the second and third sides, respectively.
In a sixth aspect, the present disclosure introduces a managed pressure drilling ("MPD") manifold adapted to receive drilling mud from a wellbore, the MPD manifold including a first .. module including one or more drilling chokes; a second module including a flow meter; and a third module operably coupled between, and in fluid communication with, the first and second modules, the third module being configured to support the second module in either: a generally horizontal orientation, or a generally vertical orientation; wherein, when the MPD
manifold receives the drilling mud from the wellbore: the one or more drilling chokes are adapted to control backpressure -- of the drilling mud within the wellbore, and the flow meter is adapted to measure a flow rate of the drilling mud received from the wellbore. In an embodiment, the first and second modules are together mounted to either a skid or a trailer so that, when so mounted, the first and second modules are together towable between operational sites. In an embodiment, the third module includes first and second flow blocks operably coupled in parallel between the first and second modules, the first -- and second flow blocks each defining an internal region and first, second, third, fourth, and fifth fluid passageways extending into the internal region. In an embodiment, when the third module supports the second module in the generally horizontal orientation: the first module is operably coupled to, and in fluid communication with, the internal region of the first flow block via the first fluid passageway thereof, and the second module is operably coupled to, and in fluid -- communication with, the internal region of the first flow block via the second fluid passageway thereof; and the first module is operably coupled to, and in fluid communication with, the internal

- 44 -region of the second flow block via the first fluid passageway thereof, and the second module is operably coupled to, and in fluid communication with, the internal region of the second flow block via the second fluid passageway thereof. In an embodiment, when the third module supports the second module in the generally vertical orientation: the first module is operably coupled to, and in fluid communication with, the internal region of the first flow block via the first fluid passageway thereof, and the second module is operably coupled to, and in fluid communication with, the internal region of the first flow block via the fifth fluid passageway thereof; and the first module is operably coupled to, and in fluid communication with, the internal region of the second flow block via the first fluid passageway thereof, and the second module is operably coupled to, and in fluid communication with, the internal region of the second flow block via the fifth fluid passageway thereof In an embodiment, the first and second flow blocks each include first, second, third, fourth, fifth, and sixth sides, the third, fourth, fifth, and sixth sides extending between the first and second sides, and the first, second, third, fourth, and fifth fluid passageways extending through the first, second, third, fourth, and fifth sides. In an embodiment, the third module further includes first, second, third, fourth, and fifth valves, the first and second valves being operably coupled to, and in fluid communication with, the first flow block and the respective first and second modules, the third and fourth valves being operably coupled to, and in fluid communication with, the second flow block and the respective first and second modules, and the fifth valve being operably coupled between, and in fluid communication with, the first and second flow blocks. In an embodiment, the third module is actuable between: a first configuration in which fluid flow is permitted from the first flow block to the second flow block via the second valve, the flow meter, and the fourth valve, and fluid flow is prevented, or at least reduced, from the first flow block to the second flow block via the fifth valve; and a second configuration in which fluid flow is prevented, or at least reduced, from the first flow block to the second flow block via the second valve, the flow meter, and the fourth valve, and fluid flow is permitted from the first flow block to the second flow block via the fifth valve. In an embodiment, in the first configuration, the first, second, third, fourth, and fifth valves are actuated so that either: the second, third, and fourth valves are open and the first and fifth valves are closed, or the first, second, and fourth valves are open and the third and fifth valves are closed; and, in the second configuration, the first, second, third, fourth, and fifth valves are actuated so that either: the third and fifth valves are open and the first, second, and fourth valves are closed, or the first and fifth valves are open and the second, third, and fourth valves are closed. In an embodiment, the second module further includes first and second flow blocks, and first and second spools, the first spool being operably coupled to, and in fluid communication with, the first flow block, the second spool being operably coupled between, and in fluid communication with, the first and second flow blocks, and the flow meter being operably coupled to, and in fluid communication with, the fourth flow block. In an embodiment, the flow meter is a coriolis flow meter.
In a seventh aspect, the present disclosure introduces a method of controlling backpressure of a drilling mud within a wellbore, the method including receiving the drilling mud from the wellbore; either: controlling, using one or more drilling chokes, the backpressure of the drilling mud within the wellbore, the one or more drilling chokes being part of a first module, or bypassing the one or more drilling chokes of the first module; either: measuring, using a flow meter, a flow rate of

- 45 -the drilling mud received from the wellbore, the flow meter being part of a second module, or bypassing the flow meter of the second module; communicating the drilling mud between the first and second modules using a third module, the third module being configured to support the second module in either: a generally horizontal orientation, or a generally vertical orientation; and discharging the drilling mud. In an embodiment, the first and second modules are together mounted to either a skid or a trailer so that, when so mounted, the first and second modules are together towable between operational sites. In an embodiment, the third module includes first and second flow blocks operably coupled in parallel between the first and second modules, the first and second flow blocks each defining an internal region and first, second, third, fourth, and fifth fluid .. passageways extending into the internal region. In an embodiment, when the third module supports the second module in the generally horizontal orientation: the first module is operably coupled to, and in fluid communication with, the internal region of the first flow block via the first fluid passageway thereof, and the second module is operably coupled to, and in fluid communication with, the internal region of the first flow block via the second fluid passageway thereof; and the first module is operably coupled to, and in fluid communication with, the internal region of the second flow block via the first fluid passageway thereof, and the second module is operably coupled to, and in fluid communication with, the internal region of the second flow block via the second fluid passageway thereof In an embodiment, when the third module supports the second module in the generally vertical orientation: the first module is operably coupled to, and in fluid communication with, the internal region of the first flow block via the first fluid passageway thereof, and the second module is operably coupled to, and in fluid communication with, the internal region of the first flow block via the fifth fluid passageway thereof; and the first module is operably coupled to, and in fluid communication with, the internal region of the second flow block via the first fluid passageway thereof, and the second module is operably coupled to, and in fluid communication with, the internal region of the second flow block via the fifth fluid passageway thereof. In an embodiment, the first and second flow blocks each include first, second, third, fourth, fifth, and sixth sides, the third, fourth, fifth, and sixth sides extending between the first and second sides, and the first, second, third, fourth, and fifth fluid passageways extending through the first, second, third, fourth, and fifth sides.
In an embodiment, the third module further includes first, second, third, fourth, and fifth valves, the first and second valves being operably coupled to, and in fluid communication with, the first flow block and the respective first and second modules, the third and fourth valves being operably coupled to, and in fluid communication with, the second flow block and the respective first and second modules, and the fifth valve being operably coupled between, and in fluid communication with, the first and second flow blocks. In an embodiment, communicating the drilling mud between the first and second modules using the third module includes: permitting fluid flow from the first flow block to the second flow block via the second valve, the flow meter, and the fourth valve; and preventing, or at least reducing, fluid flow from the first flow block to the second flow block via the fifth valve; and bypassing the flow meter of the second module includes:
preventing, or at least reducing, fluid flow from the first flow block to the second flow block via the second valve, the flow meter, and the fourth valve; and permitting fluid flow from the first flow block to the second flow block via the fifth valve. In an embodiment, communicating the drilling mud between the first and

- 46 -second modules using the third module includes actuating the first, second, third, fourth, and fifth valves so that either: the second, third, and fourth valves are open and the first and fifth valves are closed; or the first, second, and fourth valves are open and the third and fifth valves are closed; and bypassing the flow meter of the second module includes actuating the first, second, third, fourth, and fifth valves so that either: the third and fifth valves are open and the first, second, and fourth valves are closed; or the first and fifth valves are open and the second, third, and fourth valves are closed.
In an embodiment, the second module further includes first and second flow blocks, and first and second spools, the first spool being operably coupled to, and in fluid communication with, the first flow block, the second spool being operably coupled between, and in fluid communication with, the first and second flow blocks, and the flow meter being operably coupled to, and in fluid communication with, the fourth flow block. In an embodiment, the flow meter is a coriolis flow meter.
In an eighth aspect, the present disclosure introduces a choke module adapted to receive drilling mud from a wellbore, the choke module including a first fluid block defining an internal region and first and second fluid passageways extending into the internal region, the first fluid block including first and second ends, and first, second, third, and fourth sides extending between the first and second ends, the first and second fluid passageways extending through the first side. In an embodiment, the choke module further includes first and second drilling chokes operably coupled to, and in fluid communication with, the internal region of the first fluid block via the respective first and second fluid passageways thereof; wherein each of the first and second drilling chokes is adapted to control a backpressure of the drilling mud within the wellbore. In an embodiment, the choke module further includes a first valve operably coupled between, and in fluid communication with, the first fluid block and the first drilling choke; and a second valve operably coupled between, and in fluid communication with, the first fluid block and the second drilling choke. In an embodiment, the choke module further includes a second fluid block defining an internal region and first and second fluid passageways extending into the internal region, the second fluid block including first and second ends, and first, second, third, and fourth sides extending between the first and second ends, the first and second fluid passageways extending through the first side; wherein the first and second drilling chokes are operably coupled to, and in fluid communication with, the internal region of the second fluid block via the respective first and second fluid passageways thereof In an embodiment, the choke module further includes a valve operably coupled between, and in fluid communication with, the respective internal regions of the first and second fluid blocks.
In an embodiment, the choke module further includes a first valve operably coupled between, and in fluid communication with, the second fluid block and the first drilling choke;
and a second valve operably coupled between, and in fluid communication with, the second fluid block and the second drilling choke. In an embodiment, the first fluid block further defines a third fluid passageway extending through the second side thereof and adapted to receive the drilling mud from the wellb ore.
In an embodiment, the first fluid block further defines a fourth fluid passageway extending through the first end thereof and adapted to communicate the drilling mud via a measurement fitting connected to the first end.

- 47 -In a ninth aspect, the present disclosure introduces a method of controlling backpressure of a drilling mud within a wellbore, the method including receiving the drilling mud from the wellbore;
measuring, using a first sensor, a first physical property of the drilling mud before the drilling mud flows through one or more drilling chokes; flowing the drilling mud through the one or more drilling chokes; measuring, using a second sensor, the first physical property of the drilling mud after the drilling mud flows through the one or more drilling chokes; comparing the respective measurements of the first physical property taken by the first and second sensors;
determining, based on at least the comparison of the respective measurements of the first physical property taken by the first and second sensors, an amount of gas entrained in the drilling mud; and adjusting the one or more drilling chokes, based on at least the determination of the amount of gas entrained in the drilling mud, to control the backpressure of the drilling mud within the wellbore;
wherein, when the amount of gas entrained in the drilling mud is above a critical threshold, the one or more drilling chokes are adjusted to increase the backpressure of the drilling mud within the wellbore.
In an embodiment, the first physical property is density and the first and second sensors are densometers. In an embodiment, the first physical property is temperature and the first and second sensors are temperature sensors. In an embodiment, the first physical property is pressure and the first and second sensors are pressure sensors. In an embodiment, the method further includes measuring, using a third sensor, a second physical property of the drilling mud before the drilling mud flows through the one or more drilling chokes; measuring, using a fourth sensor, the second physical property of the drilling mud after the drilling mud flows through the one or more drilling chokes;
and comparing the respective measurements of the second physical property taken by the third and fourth sensors; wherein determining the amount of gas entrained in the drilling mud is further based on the comparison of the respective measurements of the second physical property taken by the third and fourth sensors. In an embodiment, the first physical property is density and the first and second sensors are densometers; and the second physical property is temperature and the third and fourth sensors are temperature sensors. In an embodiment, the first physical property is density and the first and second sensors are densometers; and the second physical property is pressure and the third and fourth sensors are pressure sensors. In an embodiment, the first physical property is temperature and the first and second sensors are temperature sensors; and the second physical property is .. pressure and the third and fourth sensors are pressure sensors. In an embodiment, the method further includes: measuring, using a fifth sensor, a third physical property of the drilling mud before the drilling mud flows through the one or more drilling chokes; measuring, using a sixth sensor, the third physical property of the drilling mud after the drilling mud flows through the one or more drilling chokes; and comparing the respective measurements of the third physical property taken by the fifth and sixth sensors; wherein determining the amount of gas entrained in the drilling mud is further based on the comparison of the respective measurements of the third physical property taken by the fifth and sixth sensors. In an embodiment, the first physical property is density and the first and second sensors are densometers; the second physical property is temperature and the third and fourth sensors are temperature sensors; and the third physical property is pressure and the fifth and sixth sensors are pressure sensors.

- 48 -In a tenth aspect, the present disclosure introduces a managed pressure drilling ("MPD") manifold adapted to receive drilling mud from a wellbore, the MPD manifold including a first module including one or more drilling chokes; and a second module including a flow meter, the second module being operably coupleable to the first module in either: a generally horizontal orientation, or a generally vertical orientation; wherein the first and second modules are together mounted to either a skid or a trailer so that, when so mounted, the first and second modules are together towable between operational sites; and wherein, when the MPD manifold receives the drilling mud from the wellbore: the one or more drilling chokes are adapted to control backpressure of the drilling mud within the wellbore; and the flow meter is adapted to measure a flow rate of the drilling mud received from the wellbore. In an embodiment, the first module further includes first and second fluid blocks, the one or more drilling chokes of the first module including first and second drilling chokes operably coupled in parallel between the first and second fluid blocks. In an embodiment, the first module further includes first, second, third, and fourth valves, the first and second valves being operably coupled to, and in fluid communication with, the first fluid block, the third and fourth valves being operably coupled to, and in fluid communication with, the second fluid block, the first drilling choke being operably coupled between, and in fluid communication with, the first and third valves, and the second drilling choke being operably coupled between, and in fluid communication with, the second and fourth valves. In an embodiment, the first module further includes a fifth valve operably coupled between, and in fluid communication with, the first and second fluid blocks. In an embodiment, the first module is actuable between: a first configuration in which: fluid flow is permitted from the second fluid block to the first fluid block via one or both of the following element combinations: the first valve, the first drilling choke, and the third valve; and the second valve, the second drilling choke, and the fourth valve; and fluid flow is prevented, or at least reduced, from the second fluid block to the first fluid block via the fifth valve; and a second configuration in which: fluid flow is permitted from the second fluid block to the first fluid block via the fifth valve; and fluid flow is prevented, or at least reduced, from the second fluid block to the first fluid block via each of the following element combinations: the first valve, the first drilling choke, and the third valve; and the second valve, the second drilling choke, and the fourth valve. In an embodiment, in the first configuration, the first, second, third, fourth, and fifth valves are actuated so that either: the first and third valves are open and the second, fourth, and fifth valves are closed, the second and fourth valves are open and the first, third, and fifth valves are closed, or the first, second, third, and fourth valves are open and the fifth valve is closed; and, in the second configuration, the first, second, third, fourth, and fifth valves are actuated so that: the first, second, third, and fourth valves are closed and the fifth valve is open. In an embodiment, the first and second fluid blocks each define an internal region and first, second, third, fourth, fifth, and sixth fluid passageways extending into the internal region. In an embodiment, the first, second, and fifth valves are in fluid communication with the internal region of the first fluid block via the respective fifth, sixth, and fourth fluid passageways thereof; and the third, fourth, and fifth valves are in fluid communication with the internal region of the second fluid block via the respective fifth, sixth, and third fluid passageways thereof. In an embodiment, the MPD manifold further includes a third module operably coupled to, and in fluid communication with: the internal region of the first fluid

- 49 -block via the second fluid passageway thereof; the internal region of the second fluid block via the second fluid passageway thereof; and the flow meter of the second module. In an embodiment, the first module further includes one or both of: a first flow fitting operably coupled to, and in fluid communication with, the internal region of the second fluid block via the fourth fluid passageway thereof, the first flow fitting being adapted to receive the drilling mud from the wellbore; and a second flow fitting operably coupled to, and in fluid communication with, the internal region of the first fluid block via the third fluid passageway thereof, the second flow fitting being adapted to discharge the drilling mud from the first module. In an embodiment, the first module further includes one or both of: a first measurement fitting operably coupled to, and in fluid communication with, the internal region of the first fluid block via the first fluid passageway thereof; and a second measurement fitting operably coupled to, and in fluid communication with, the internal region of the second fluid block via the first fluid passageway thereof. In an embodiment, the first and second fluid blocks each include first and second ends, and first, second, third, and fourth sides extending between the first and second ends, the first and second fluid passageways extending through the first and second ends, respectively, the third and fourth fluid passageways extending through the first and second sides, respectively, and the fifth and sixth fluid passageways each extending through the third side. In an embodiment, the second module further includes first and second flow blocks, and first and second spools, the first spool being operably coupled to, and in fluid communication with, the first flow block, the second spool being operably coupled between, and in fluid communication with, the first and second flow blocks, and the flow meter being operably coupled to, and in fluid communication with, the second flow block. In an embodiment, the second module further includes one or both of: a first measurement fitting operably coupled to, and in fluid communication with, the first flow block; and a second measurement fitting operably coupled to, and in fluid communication with, the second flow block. In an embodiment, the flow meter is a coriolis flow meter. In an embodiment, the MPD manifold further includes a third module, the third module including first and second flow blocks and first, second, third, and fourth valves, the first valve being operably coupled to, and in fluid communication with, the first flow block and the first module, the second valve being operably coupled to, and in fluid communication with, the first flow block and the second module, the third valve being operably coupled to, and in fluid communication with, the second flow block and the first module, and the fourth valve being operably coupled to, and in fluid communication with, the second flow block and the second module. In an embodiment, the third module further includes a fifth valve operably coupled between, and in fluid communication with, the first and second flow blocks; and wherein the third module is actuable between: a first configuration in which fluid flow is permitted from the first flow block to the second flow block via the second valve, the flow meter, and the fourth valve, and fluid flow is prevented, or at least reduced, from the first flow block to the second flow block via the fifth valve; and a second configuration in which fluid flow is prevented, or at least reduced, from the first flow block to the second flow block via the second valve, the flow meter, and the fourth valve, and fluid flow is permitted from the first flow block to the second flow block via the fifth valve. In an embodiment, in the first configuration, the first, second, third, fourth, and fifth valves are actuated so that either:
the second, third, and fourth valves are open and the first and fifth valves are closed, or the first,

- 50 -second, and fourth valves are open and the third and fifth valves are closed;
and, in the second configuration, the first, second, third, fourth, and fifth valves are actuated so that either: the third and fifth valves are open and the first, second, and fourth valves are closed, or the first and fifth valves are open and the second, third, and fourth valves are closed. In an embodiment, the first and second flow blocks each define an internal region, and first, second, third, and fourth fluid passageways, each extending into the internal region. In an embodiment, the first, second, and fifth valves are in fluid communication with the internal region of the first flow block via the respective first, second, and fourth fluid passageways thereof; and the third, fourth, and fifth valves are in fluid communication with the internal region of the second flow block via the respective first, second, and third fluid passageways thereof. In an embodiment, the first and second fluid passageways of the first flow block are generally coaxial and the first and second fluid passageways of the second flow block are generally coaxial so that the second module, including the flow meter, extends in the generally horizontal orientation. In an embodiment, the first and second fluid passageways of the first flow block define generally perpendicular axes and the first and second fluid passageways of the second flow block define generally perpendicular axes so that the second module, including the flow meter, extends in the generally vertical orientation. In an embodiment, the first and second flow blocks each include first, second, third, fourth, fifth, and sixth sides, the third, fourth, fifth, and sixth sides extending between the first and second sides, the first, third, and fourth fluid passageways extending through the respective first, third, and fourth sides, and the second fluid passageway extending through either the second side or the fifth side. In an embodiment, the third module further includes one or both of: a first flow fitting operably coupled to, and in fluid communication with, the internal region of the first flow block via the third fluid passageway thereof, the first flow fitting being adapted to receive the drilling mud from the wellbore; or a second flow fitting operably coupled to, and in fluid communication with, the internal region of the second flow block via the fourth fluid passageway thereof, the second flow fitting being adapted to discharge the drilling mud from the third module.
In an eleventh aspect, the present disclosure introduces a managed pressure drilling ("MPD") manifold adapted to receive drilling mud from a wellbore, the MPD manifold including a first module including: first and second fluid blocks, and first and second drilling chokes operably coupled in parallel between the first and second fluid blocks; and a second module including a flow meter; wherein, when the MPD manifold receives the drilling mud from the wellbore: the one or more drilling chokes are adapted to control backpressure of the drilling mud within the wellbore;
and the flow meter is adapted to measure a flow rate of the drilling mud received from the wellbore.
In an embodiment, the first module further includes first, second, third, and fourth valves, the first and second valves being operably coupled to, and in fluid communication with, the first fluid block, the third and fourth valves being operably coupled to, and in fluid communication with, the second fluid block, the first drilling choke being operably coupled between, and in fluid communication with, the first and third valves, and the second drilling choke being operably coupled between, and in fluid communication with, the second and fourth valves. In an embodiment, the first module further includes a fifth valve operably coupled between, and in fluid communication with, the first and second fluid blocks. In an embodiment, the first module is actuable between: a first

-51-configuration in which: fluid flow is permitted from the second fluid block to the first fluid block via one or both of the following element combinations: the first valve, the first drilling choke, and the third valve; and the second valve, the second drilling choke, and the fourth valve; and fluid flow is prevented, or at least reduced, from the second fluid block to the first fluid block via the fifth valve;
and a second configuration in which: fluid flow is permitted from the second fluid block to the first fluid block via the fifth valve; and fluid flow is prevented, or at least reduced, from the second fluid block to the first fluid block via each of the following element combinations:
the first valve, the first drilling choke, and the third valve; and the second valve, the second drilling choke, and the fourth valve. In an embodiment, in the first configuration, the first, second, third, fourth, and fifth valves are actuated so that either: the first and third valves are open and the second, fourth, and fifth valves are closed, the second and fourth valves are open and the first, third, and fifth valves are closed, or the first, second, third, and fourth valves are open and the fifth valve is closed; and, in the second configuration, the first, second, third, fourth, and fifth valves are actuated so that: the first, second, third, and fourth valves are closed and the fifth valve is open. In an embodiment, the first and second fluid blocks each define an internal region and first, second, third, fourth, fifth, and sixth fluid passageways extending into the internal region. In an embodiment, the first, second, and fifth valves are in fluid communication with the internal region of the first fluid block via the respective fifth, sixth, and fourth fluid passageways thereof; and the third, fourth, and fifth valves are in fluid communication with the internal region of the second fluid block via the respective fifth, sixth, and third fluid passageways thereof. In an embodiment, the IVIPD manifold further includes a third module operably coupled to, and in fluid communication with: the internal region of the first fluid block via the second fluid passageway thereof; the internal region of the second fluid block via the second fluid passageway thereof; and the flow meter of the second module. In an embodiment, the first module further includes one or both of: a first flow fitting operably coupled to, and in fluid communication with, the internal region of the second fluid block via the fourth fluid passageway thereof, the first flow fitting being adapted to receive the drilling mud from the wellbore; and a second flow fitting operably coupled to, and in fluid communication with, the internal region of the first fluid block via the third fluid passageway thereof, the second flow fitting being adapted to discharge the drilling mud from the first module. In an embodiment, the first module further includes one or both of: a first measurement fitting operably coupled to, and in fluid communication with, the internal region of the first fluid block via the first fluid passageway thereof; and a second measurement fitting operably coupled to, and in fluid communication with, the internal region of the second fluid block via the first fluid passageway thereof. In an embodiment, the first and second fluid blocks each include first and second ends, and first, second, third, and fourth sides extending between the first and second ends, the first and second fluid passageways extending through the first and second ends, respectively, the third and fourth fluid passageways extending through the first and second sides, respectively, and the fifth and sixth fluid passageways each extending through the third side. In an embodiment, the second module further includes first and second flow blocks, and first and second spools, the first spool being operably coupled to, and in fluid communication with, the first flow block, the second spool being operably coupled between, and in fluid communication with, the first and second flow blocks, and the flow meter being operably coupled to, and in fluid

- 52 -communication with, the second flow block. In an embodiment, the second module further includes one or both of: a first measurement fitting operably coupled to, and in fluid communication with, the first flow block; and a second measurement fitting operably coupled to, and in fluid communication with, the second flow block. In an embodiment, the flow meter is a coriolis flow meter.
In a twelfth aspect, the present disclosure introduces a managed pressure drilling ("MPD") manifold adapted to receive drilling mud from a wellbore, the MPD manifold including a first module including one or more drilling chokes; a second module including a flow meter; and a third module including first and second flow blocks operably coupled in parallel between the first and second modules; wherein, when the MPD manifold receives the drilling mud from the wellbore: the one or more drilling chokes are adapted to control backpressure of the drilling mud within the wellbore; and the flow meter is adapted to measure a flow rate of the drilling mud received from the wellbore. In an embodiment, the third module further includes first, second, third, and fourth valves, the first and second valves being operably coupled to, and in fluid communication with, the first flow block and the respective first and second modules, and the third and fourth valves being operably coupled to, and in fluid communication with, the second flow block and the respective first and second modules. In an embodiment, the third module further includes a fifth valve operably coupled between, and in fluid communication with, the first and second flow blocks; and wherein the third module is actuable between: a first configuration in which fluid flow is permitted from the first flow block to the second flow block via the second valve, the flow meter, and the fourth valve, and fluid flow is prevented, or at least reduced, from the first flow block to the second flow block via the fifth valve; and a second configuration in which fluid flow is prevented, or at least reduced, from the first flow block to the second flow block via the second valve, the flow meter, and the fourth valve, and fluid flow is permitted from the first flow block to the second flow block via the fifth valve. In an embodiment, in the first configuration, the first, second, third, fourth, and fifth valves are actuated so that either: the second, third, and fourth valves are open and the first and fifth valves are closed, or the first, second, and fourth valves are open and the third and fifth valves are closed; and wherein, in the second configuration, the first, second, third, fourth, and fifth valves are actuated so that either: the third and fifth valves are open and the first, second, and fourth valves are closed, or the first and fifth valves are open and the second, third, and fourth valves are closed. In an embodiment, the first and second flow blocks each define an internal region, and first, second, third, and fourth fluid passageways, each extending into the internal region.
In an embodiment, the first, second, and fifth valves are in fluid communication with the internal region of the first flow block via the respective first, second, and fourth fluid passageways thereof;
and the third, fourth, and fifth valves are in fluid communication with the internal region of the second flow block via the respective first, second, and third fluid passageways thereof In an embodiment, the first and second fluid passageways of the first flow block are generally coaxial and the first and second fluid passageways of the second flow block are generally coaxial so that the second module, including the flow meter, extends in a generally horizontal orientation. In an embodiment, the first and second fluid passageways of the first flow block define generally perpendicular axes and the first and second fluid passageways of the second flow block define generally perpendicular axes so that the second module, including the flow meter, extends in a generally vertical orientation. In an

- 53 -embodiment, the first and second flow blocks each include first, second, third, fourth, fifth, and sixth sides, the third, fourth, fifth, and sixth sides extending between the first and second sides, the first, third, and fourth fluid passageways extending through the first, third, and fourth sides, respectively, and the second fluid passageway extending through either the second side or the fifth side. In an embodiment, the third module further includes one or both of: a first flow fitting operably coupled to, and in fluid communication with, the internal region of the first flow block via the third fluid passageway thereof, the first flow fitting being adapted to receive the drilling mud from the wellbore; and a second flow fitting operably coupled to, and in fluid communication with, the internal region of the second flow block via the fourth fluid passageway thereof, the second flow fitting being adapted to discharge the drilling mud from the third module. In an embodiment, the second module further includes third and fourth flow blocks, and first and second spools, the first spool being operably coupled to, and in fluid communication with, the third flow block, the second spool being operably coupled between, and in fluid communication with, the third and fourth flow blocks, and the flow meter being operably coupled to, and in fluid communication with, the fourth flow block. In an embodiment, the second module further includes one or both of: a first measurement fitting operably coupled to, and in fluid communication with, the third flow block; and a second measurement fitting operably coupled to, and in fluid communication with, the fourth flow block. In an embodiment, the flow meter is a coriolis flow meter.
In a thirteenth aspect, the present disclosure introduces a method of controlling backpressure of a drilling mud within a wellbore, the method including receiving the drilling mud from the wellbore; either: controlling, using one or more drilling chokes, the backpressure of the drilling mud within the wellbore, the one or more drilling chokes being part of a first module, or bypassing the one or more drilling chokes of the first module; either: measuring, using a flow meter, a flow rate of the drilling mud received from the wellbore, the flow meter being part of a second module, or bypassing the flow meter of the second module; and discharging the drilling mud; wherein the second module is operably coupleable to the first module in either: a generally horizontal orientation, or a generally vertical orientation; and wherein the first and second modules are together mounted to either a skid or a trailer so that, when so mounted, the first and second modules are together towable between operational sites. In an embodiment, the first module further includes first and second fluid blocks, the one or more drilling chokes of the first module including first and second drilling chokes operably coupled in parallel between the first and second fluid blocks. In an embodiment, the first module further includes first, second, third, and fourth valves, the first and second valves being operably coupled to, and in fluid communication with, the first fluid block, the third and fourth valves being operably coupled to, and in fluid communication with, the second fluid block, the first drilling choke being operably coupled between, and in fluid communication with, the first and third valves, and the second drilling choke being operably coupled between, and in fluid communication with, the second and fourth valves. In an embodiment, the first module further includes a fifth valve operably coupled between, and in fluid communication with, the first and second fluid blocks. In an embodiment, controlling, using the one or more drilling chokes, the backpressure of the drilling mud within the wellbore includes: permitting fluid flow from the second fluid block to the first fluid block via one or both of the following element combinations: the first

- 54 -valve, the first drilling choke, and the third valve; and the second valve, the second drilling choke, and the fourth valve; and preventing, or at least reducing, fluid flow from the second fluid block to the first fluid block via the fifth valve; and bypassing the one or more drilling chokes of the first module includes: permitting fluid flow from the second fluid block to the first fluid block via the fifth valve; and preventing, or at least reducing, fluid flow from the second fluid block to the first fluid block via each of the following element combinations: the first valve, the first drilling choke, and the third valve; and the second valve, the second drilling choke, and the fourth valve. In an embodiment, controlling, using the one or more drilling chokes, the backpressure of the drilling mud within the wellbore includes actuating the first, second, third, fourth, and fifth valves so that either:
.. the first and third valves are open and the second, fourth, and fifth valves are closed, the second and fourth valves are open and the first, third, and fifth valves are closed, or the first, second, third, and fourth valves are open and the fifth valve is closed; and bypassing the one or more drilling chokes of the first module includes actuating the first, second, third, fourth, and fifth valves so that: the first, second, third, and fourth valves are closed and the fifth valve is open. In an embodiment, the first and second fluid blocks each define an internal region and first, second, third, fourth, fifth, and sixth fluid passageways extending into the internal region. In an embodiment, the first, second, and fifth valves are in fluid communication with the internal region of the first fluid block via the respective fifth, sixth, and fourth fluid passageways thereof; and the third, fourth, and fifth valves are in fluid communication with the internal region of the second fluid block via the respective fifth, sixth, and third fluid passageways thereof. In an embodiment, the method further includes communicating, using a third module, the drilling mud to the second module, the third module being operably coupled to, and in fluid communication with: the internal region of the first fluid block via the second fluid passageway thereof; the internal region of the second fluid block via the second fluid passageway thereof; and the flow meter of the second module. In an embodiment, receiving the drilling mud from the wellbore includes receiving, via a first flow fitting, the drilling mud from the wellbore, the first flow fitting being operably coupled to, and in fluid communication with either:
the internal region of the second fluid block via the fourth fluid passageway thereof, or the third module; and discharging the drilling mud includes discharging, via a second flow fitting, the drilling mud, the second flow fitting being operably coupled to, and in fluid communication with, either: the third module, or the internal region of the first fluid block via the third fluid passageway thereof. In an embodiment, the first module further includes one or both of: a first measurement fitting operably coupled to, and in fluid communication with, the internal region of the first fluid block via the first fluid passageway thereof; and a second measurement fitting operably coupled to, and in fluid communication with, the internal region of the second fluid block via the first fluid passageway thereof In an embodiment, the first and second fluid blocks each include first and second ends, and first, second, third, and fourth sides extending between the first and second ends, the first and second fluid passageways extending through the first and second ends, respectively, the third and fourth fluid passageways extending through the first and second sides, respectively, and the fifth and sixth fluid passageways each extending through the third side. In an embodiment, the second module further includes first and second flow blocks, and first and second spools, the first spool being operably coupled to, and in fluid communication with, the first flow block, the second spool

- 55 -being operably coupled between, and in fluid communication with, the first and second flow blocks, and the flow meter being operably coupled to, and in fluid communication with, the second flow block. In an embodiment, the second module further includes one or both of: a first measurement fitting operably coupled to, and in fluid communication with, the first flow block; and a second measurement fitting operably coupled to, and in fluid communication with, the second flow block.
In an embodiment, the flow meter is a coriolis flow meter. In an embodiment, the method further includes communicating, using a third module, the drilling fluid to the second module, the third module including first and second flow blocks and first, second, third, and fourth valves, the first valve being operably coupled to, and in fluid communication with, the first flow block and the first module, the second valve being operably coupled to, and in fluid communication with, the first flow block and the second module, the third valve being operably coupled to, and in fluid communication with, the second flow block and the first module, and the fourth valve being operably coupled to, and in fluid communication with, the second flow block and the second module.
In an embodiment, the third module further includes a fifth valve operably coupled between, and in fluid communication with, the first and second flow blocks. In an embodiment, communicating, using the third module, the drilling fluid to the second module includes: permitting fluid flow from the first flow block to the second flow block via the second valve, the flow meter, and the fourth valve;
and preventing, or at least reducing, fluid flow from the first flow block to the second flow block via the fifth valve; and wherein bypassing the flow meter of the second module includes: preventing, or at least reducing, fluid flow from the first flow block to the second flow block via the second valve, the flow meter, and the fourth valve; and permitting fluid flow from the first flow block to the second flow block via the fifth valve. In an embodiment, communicating, using the third module, the drilling fluid to the second module includes actuating the first, second, third, fourth, and fifth valves so that either: the second, third, and fourth valves are open and the first and fifth valves are closed, or the first, second, and fourth valves are open and the third and fifth valves are closed; and bypassing the flow meter of the second module includes actuating the first, second, third, fourth, and fifth valves so that either: the third and fifth valves are open and the first, second, and fourth valves are closed, or the first and fifth valves are open and the second, third, and fourth valves are closed.
In an embodiment, the first and second flow blocks each define an internal region, and first, second, third, and fourth fluid passageways, each extending into the internal region.
In an embodiment, the first, second, and fifth valves are in fluid communication with the internal region of the first flow block via the respective first, second, and fourth fluid passageways thereof;
and the third, fourth, and fifth valves are in fluid communication with the internal region of the second flow block via the respective first, second, and third fluid passageways thereof In an embodiment, the first and second fluid passageways of the first flow block are generally coaxial and the first and second fluid passageways of the second flow block are generally coaxial so that the second module, including the flow meter, extends in the generally horizontal orientation. In an embodiment, the first and second fluid passageways of the first flow block define generally perpendicular axes and the first and second fluid passageways of the second flow block define generally perpendicular axes so that the .. second module, including the flow meter, extends in the generally vertical orientation. In an embodiment, the first and second flow blocks each include first, second, third, fourth, fifth, and

- 56 -sixth sides, the third, fourth, fifth, and sixth sides extending between the first and second sides, the first, third, and fourth fluid passageways extending through the respective first, third, and fourth sides, and the second fluid passageway extending through either the second side or the fifth side. In an embodiment, receiving the drilling mud from the wellbore includes receiving, via a first flow fitting, the drilling mud from the wellbore, the first flow fitting being operably coupled to, and in fluid communication with either: the first module, or the internal region of the first flow block via the third fluid passageway thereof; and discharging the drilling mud includes discharging, via a second flow fitting, the drilling mud, the second flow fitting being operably coupled to, and in fluid communication with, either: the internal region of the second flow block via the fourth fluid passageway thereof, or the first module.
In a fourteenth aspect, the present disclosure introduces a method of controlling backpressure of a drilling mud within a wellbore, the method including receiving the drilling mud from the wellbore; either: controlling, using one or more drilling chokes, the backpressure of the drilling mud within the wellbore, the one or more drilling chokes being part of a first module, or bypassing the one or more drilling chokes of the first module; either: measuring, using a flow meter, a flow rate of the drilling mud received from the wellbore, the flow meter being part of a second module, or bypassing the flow meter of the second module; and discharging the drilling mud; wherein the first module further includes first and second fluid blocks, the one or more drilling chokes of the first module including first and second drilling chokes operably coupled in parallel between the first and second fluid blocks. In an embodiment, the first module further includes first, second, third, and fourth valves, the first and second valves being operably coupled to, and in fluid communication with, the first fluid block, the third and fourth valves being operably coupled to, and in fluid communication with, the second fluid block, the first drilling choke being operably coupled between, and in fluid communication with, the first and third valves, and the second drilling choke being operably coupled between, and in fluid communication with, the second and fourth valves. In an embodiment, the first module further includes a fifth valve operably coupled between, and in fluid communication with, the first and second fluid blocks. In an embodiment, controlling, using the one or more drilling chokes, the backpressure of the drilling mud within the wellbore includes permitting fluid flow from the second fluid block to the first fluid block via one or both of the following element combinations: the first valve, the first drilling choke, and the third valve; and the second valve, the second drilling choke, and the fourth valve; and preventing, or at least reducing, fluid flow from the second fluid block to the first fluid block via the fifth valve; and bypassing the one or more drilling chokes of the first module includes permitting fluid flow from the second fluid block to the first fluid block via the fifth valve; and preventing, or at least reducing, fluid flow from the second fluid block to the first fluid block via each of the following element combinations: the first valve, the first drilling choke, and the third valve; and the second valve, the second drilling choke, and the fourth valve. In an embodiment, controlling, using the one or more drilling chokes, the backpressure of the drilling mud within the wellbore includes actuating the first, second, third, fourth, and fifth valves so that either: the first and third valves are open and the second, fourth, and fifth valves are closed, the second and fourth valves are open and the first, third, and fifth valves are closed, or the first, second, third, and fourth valves are open and the fifth valve is closed; and

- 57 -bypassing the one or more drilling chokes of the first module includes actuating the first, second, third, fourth, and fifth valves so that: the first, second, third, and fourth valves are closed and the fifth valve is open. In an embodiment, the first and second fluid blocks each define an internal region and first, second, third, fourth, fifth, and sixth fluid passageways extending into the internal .. region. In an embodiment, the first, second, and fifth valves are in fluid communication with the internal region of the first fluid block via the respective fifth, sixth, and fourth fluid passageways thereof; and the third, fourth, and fifth valves are in fluid communication with the internal region of the second fluid block via the respective fifth, sixth, and third fluid passageways thereof. In an embodiment, the method further includes communicating, using a third module, the drilling mud to the second module, the third module being operably coupled to, and in fluid communication with:
the internal region of the first fluid block via the second fluid passageway thereof; the internal region of the second fluid block via the second fluid passageway thereof; and the flow meter of the second module. In an embodiment, receiving the drilling mud from the wellbore includes receiving, via a first flow fitting, the drilling mud from the wellbore, the first flow fitting being operably .. coupled to, and in fluid communication with either: the internal region of the second fluid block via the fourth fluid passageway thereof, or the third module; and discharging the drilling mud includes discharging, via a second flow fitting, the drilling mud, the second flow fitting being operably coupled to, and in fluid communication with, either: the third module, or the internal region of the first fluid block via the third fluid passageway thereof. In an embodiment, the first module further includes one or both of: a first measurement fitting operably coupled to, and in fluid communication with, the internal region of the first fluid block via the first fluid passageway thereof; and a second measurement fitting operably coupled to, and in fluid communication with, the internal region of the second fluid block via the first fluid passageway thereof. In an embodiment, the first and second fluid blocks each include first and second ends, and first, second, third, and fourth sides extending between the first and second ends, the first and second fluid passageways extending through the first and second ends, respectively, the third and fourth fluid passageways extending through the first and second sides, respectively, and the fifth and sixth fluid passageways each extending through the third side. In an embodiment, the second module further includes first and second flow blocks, and first and second spools, the first spool being operably coupled to, and in fluid communication with, the first flow block, the second spool being operably coupled between, and in fluid communication with, the first and second flow blocks, and the flow meter being operably coupled to, and in fluid communication with, the second flow block. In an embodiment, the second module further includes one or both of: a first measurement fitting operably coupled to, and in fluid communication with, the first flow block; and a second measurement fitting operably coupled to, and in fluid communication with, the second flow block. In an embodiment, the flow meter is a coriolis flow meter.
In a fifteenth aspect, the present disclosure introduces a method of controlling backpressure of a drilling mud within a wellbore, the method including receiving the drilling mud from the wellbore; either: controlling, using one or more drilling chokes, the backpressure of the drilling mud within the wellbore, the one or more drilling chokes being part of a first module, or bypassing the one or more drilling chokes of the first module; either: measuring, using a flow meter, a flow rate of the drilling mud received from the wellbore, the flow meter being part of a second module, or

- 58 -bypassing the flow meter of the second module; communicating, using a third module, the drilling fluid to the second module, the third module including first and second flow blocks operably coupled in parallel between the first and second modules; and discharging the drilling mud. In an embodiment, the third module further includes first, second, third, and fourth valves, the first valve being operably coupled to, and in fluid communication with, the first flow block and the first module, the second valve being operably coupled to, and in fluid communication with, the first flow block and the second module, the third valve being operably coupled to, and in fluid communication with, the second flow block and the first module, and the fourth valve being operably coupled to, and in fluid communication with, the second flow block and the second module.
In an embodiment, the third module further includes a fifth valve operably coupled between, and in fluid communication with, the first and second flow blocks. In an embodiment, communicating, using the third module, the drilling fluid to the second module includes: permitting fluid flow from the first flow block to the second flow block via the second valve, the flow meter, and the fourth valve;
and preventing, or at least reducing, fluid flow from the first flow block to the second flow block via the fifth valve; and bypassing the flow meter of the second module includes:
preventing, or at least reducing, fluid flow from the first flow block to the second flow block via the second valve, the flow meter, and the fourth valve; and permitting fluid flow from the first flow block to the second flow block via the fifth valve. In an embodiment, communicating, using the third module, the drilling fluid to the second module includes actuating the first, second, third, fourth, and fifth valves so that either: the second, third, and fourth valves are open and the first and fifth valves are closed, or the first, second, and fourth valves are open and the third and fifth valves are closed; and bypassing the flow meter of the second module includes actuating the first, second, third, fourth, and fifth valves so that either: the third and fifth valves are open and the first, second, and fourth valves are closed, or the first and fifth valves are open and the second, third, and fourth valves are closed. In an embodiment, the first and second flow blocks each define an internal region, and first, second, third, and fourth fluid passageways, each extending into the internal region. In an embodiment, the first, second, and fifth valves are in fluid communication with the internal region of the first flow block via the respective first, second, and fourth fluid passageways thereof and the third, fourth, and fifth valves are in fluid communication with the internal region of the second flow block via the .. respective first, second, and third fluid passageways thereof In an embodiment, the first and second fluid passageways of the first flow block are generally coaxial and the first and second fluid passageways of the second flow block are generally coaxial so that the second module, including the flow meter, extends in a generally horizontal orientation. In an embodiment, the first and second fluid passageways of the first flow block define generally perpendicular axes and the first and second fluid passageways of the second flow block define generally perpendicular axes so that the second module, including the flow meter, extends in a generally vertical orientation. In an embodiment, the first and second flow blocks each include first, second, third, fourth, fifth, and sixth sides, the third, fourth, fifth, and sixth sides extending between the first and second sides, the first, third, and fourth fluid passageways extending through the respective first, third, and fourth sides, and the second fluid passageway extending through either the second side or the fifth side. In an embodiment, receiving the drilling mud from the wellbore includes receiving, via a first flow

- 59 -fitting, the drilling mud from the wellbore, the first flow fitting being operably coupled to, and in fluid communication with either: the first module, or the internal region of the first flow block via the third fluid passageway thereof; and discharging the drilling mud includes discharging, via a second flow fitting, the drilling mud, the second flow fitting being operably coupled to, and in fluid communication with, either: the internal region of the second flow block via the fourth fluid passageway thereof, or the first module. In an embodiment, the second module further includes first and second flow blocks, and first and second spools, the first spool being operably coupled to, and in fluid communication with, the first flow block, the second spool being operably coupled between, and in fluid communication with, the first and second flow blocks, and the flow meter being operably coupled to, and in fluid communication with, the second flow block.
In an embodiment, the second module further includes one or both of: a first measurement fitting operably coupled to, and in fluid communication with, the first flow block; and a second measurement fitting operably coupled to, and in fluid communication with, the second flow block. In an embodiment, the flow meter is a coriolis flow meter.
It is understood that variations may be made in the foregoing without departing from the scope of the present disclosure.
In some embodiments, the elements and teachings of the various embodiments may be combined in whole or in part in some or all of the embodiments. In addition, one or more of the elements and teachings of the various embodiments may be omitted, at least in part, and/or combined, at least in part, with one or more of the other elements and teachings of the various embodiments.
In some embodiments, while different steps, processes, and procedures are described as appearing as distinct acts, one or more of the steps, one or more of the processes, and/or one or more of the procedures may also be performed in different orders, simultaneously and/or sequentially. In some embodiments, the steps, processes and/or procedures may be merged into one or more steps, processes and/or procedures.
In some embodiments, one or more of the operational steps in each embodiment may be omitted. Moreover, in some instances, some features of the present disclosure may be employed without a corresponding use of the other features. Moreover, one or more of the above-described embodiments and/or variations may be combined in whole or in part with any one or more of the other above-described embodiments and/or variations.
In the foregoing description of certain embodiments, specific terminology has been resorted to for the sake of clarity. However, the disclosure is not intended to be limited to the specific terms so selected, and it is to be understood that each specific term includes other technical equivalents which operate in a similar manner to accomplish a similar technical purpose.
Terms such as "left"
and right", "front" and "rear", "above" and "below" and the like are used as words of convenience to provide reference points and are not to be construed as limiting terms.
In this specification, the word "comprising" is to be understood in its "open"
sense, that is, in the sense of "including", and thus not limited to its "closed" sense, that is the sense of "consisting only of'. A corresponding meaning is to be attributed to the corresponding words "comprise", "comprised" and "comprises" where they appear.

- 60 -

61 Although some embodiments have been described in detail above, the embodiments described are illustrative only and are not limiting, and those skilled in the art will readily appreciate that many other modifications, changes and/or substitutions are possible in the embodiments without materially departing from the novel teachings and advantages of the present disclosure. Accordingly, all such modifications, changes, and/or substitutions are intended to be included within the scope of this disclosure as defined in the following claims. In the claims, any means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents, but also equivalent structures. Moreover, it is the express intention of the applicant not to invoke 35 U.S.C. 112, paragraph 6 for any limitations of any of the claims herein, except for those in which the claim expressly uses the word "means"
together with an associated function.

Claims

Claims What is claimed is:

1. A managed pressure drilling ("MPD") manifold adapted to receive drilling mud from a wellbore, the MPD manifold comprising:
a first module comprising one or more drilling chokes;
a second module comprising a flow meter; and a third module comprising first and second flow blocks operably coupled in parallel between the first and second modules;
wherein the one or more drilling chokes are adapted to control backpressure of the drilling mud within the wellbore; and wherein the flow meter is adapted to measure a flow rate of the drilling mud received from the wellbore.

2. The MPD manifold of claim 1, wherein the third module further comprises:
a first valve operably coupled between, and in fluid communication with, the first flow block and the first module;
a second valve operably coupled between, and in fluid communication with, the first flow block and the second module;
a third valve operably coupled between, and in fluid communication with, the second flow block and the first module; and a fourth valve operably coupled between, and in fluid communication with, the second flow block and the second module.

3. The MPD manifold of claim 2, wherein the third module further comprises a fifth valve operably coupled between, and in fluid communication with, the first and second flow blocks.

4. The MPD manifold of claim 3, wherein the third module is actuable between:
a first configuration in which fluid flow is permitted from the first flow block to the second flow block via the second valve, the flow meter, and the fourth valve, and fluid flow is prevented, or at least reduced, from the first flow block to the second flow block via the fifth valve; and a second configuration in which fluid flow is prevented, or at least reduced, from the first flow block to the second flow block via the second valve, the flow meter, and the fourth valve, and fluid flow is permitted from the first flow block to the second flow block via the fifth valve.

5. The MPD manifold of claim 4, wherein, in the first configuration, the first, second, third, fourth, and fifth valves are actuated so that either:

the second, third, and fourth valves are open and the first and fifth valves are closed, or the first, second, and fourth valves are open and the third and fifth valves are closed;
and wherein, in the second configuration, the first, second, third, fourth, and fifth valves are actuated so that either:
the third and fifth valves are open and the first, second, and fourth valves are closed, or the first and fifth valves are open and the second, third, and fourth valves are closed.

6. The MPD manifold of claim 3, wherein the first and second flow blocks each define an internal region, and first, second, third, and fourth fluid passageways, each extending into the internal region;
wherein the first, second, and fifth valves are in fluid communication with the internal region of the first flow block via the respective first, second, and fourth fluid passageways thereof; and wherein the third, fourth, and fifth valves are in fluid communication with the internal region of the second flow block via the respective first, second, and third fluid passageways thereof

7. The MPD manifold of claim 6, wherein the third module further comprises one or both of:
a first flow fitting operably coupled to, and in fluid communication with, the internal region of the first flow block via the third fluid passageway thereof, the first flow fitting being adapted to receive the drilling mud from the wellbore;
and a second flow fitting operably coupled to, and in fluid communication with, the internal region of the second flow block via the fourth fluid passageway thereof, the second flow fitting being adapted to discharge the drilling mud from the third module.

8. The MPD manifold of claim 1, wherein the first and second flow blocks each define an internal region, and first, second, third, and fourth fluid passageways, each extending into the internal region; and wherein the MPD manifold has:
a first configuration in which fluid flow is permitted between the first and second modules via the first and second passageways of the first flow bock; and a second configuration in which fluid flow is permitted between the first and second modules via the first and second passageways of the second flow block.

9. The MPD manifold of claim 8, wherein the first and second fluid passageways of the first flow block are generally coaxial, and the first and second fluid passageways of the second flow block are generally coaxial, so that the second module, including the flow meter, extends in a generally horizontal orientation.

10. The MPD manifold of claim 8, wherein the first and second fluid passageways of the first flow block define generally perpendicular axes, and the first and second fluid passageways of the second flow block define generally perpendicular axes, so that the second module, including the flow meter, extends in a generally vertical orientation.

11. The MPD manifold of claim 8, wherein the first and second flow blocks each comprise first, second, third, fourth, fifth, and sixth sides, the third, fourth, fifth, and sixth sides extending between the first and second sides, the first, third, and fourth fluid passageways extending through the first, third, and fourth sides, respectively, and the second fluid passageway extending through either the second side or the fifth side.

12. The MPD manifold of claim 8, wherein the second module further comprises third and fourth flow blocks, and first and second spools, the first spool being operably coupled to, and in fluid communication with, the third flow block, the second spool being operably coupled between, and in fluid communication with, the third and fourth flow blocks, and the flow meter being operably coupled to, and in fluid communication with, the fourth flow block.

13. A managed pressure drilling ("MPD") manifold adapted to receive drilling mud from a wellbore, the MPD manifold comprising:
a first module comprising one or more drilling chokes;
a second module comprising a flow meter; and a third module operably coupled between, and in fluid communication with, the first and second modules, the third module being configured to support the second module in either:
a generally horizontal orientation; or a generally vertical orientation;
wherein the one or more drilling chokes are adapted to control backpressure of the drilling mud within the wellbore; and wherein the flow meter is adapted to measure a flow rate of the drilling mud received from the wellbore.

14. The MPD manifold of claim 13, wherein the first and second modules are together mounted to either a skid or a trailer so that, when so mounted, the first and second modules are together towable between operational sites.

15. The MPD manifold of claim 13, wherein the third module comprises first and second flow blocks operably coupled in parallel between the first and second modules, the first and second flow blocks each defining an internal region and first, second, third, fourth, and fifth fluid passageways extending into the internal region.

16. The MPD manifold of claim 15, wherein, when the third module supports the second module in the generally horizontal orientation:
the first module is operably coupled to, and in fluid communication with, the internal region of the first flow block via the first fluid passageway thereof, and the second module is operably coupled to, and in fluid communication with, the internal region of the first flow block via the second fluid passageway thereof;
and the first module is operably coupled to, and in fluid communication with, the internal region of the second flow block via the first fluid passageway thereof, and the second module is operably coupled to, and in fluid communication with, the internal region of the second flow block via the second fluid passageway thereof.

17. The MPD manifold of claim 16, wherein, when the third module supports the second module in the generally vertical orientation:
the first module is operably coupled to, and in fluid communication with, the internal region of the first flow block via the first fluid passageway thereof, and the second module is operably coupled to, and in fluid communication with, the internal region of the first flow block via the fifth fluid passageway thereof; and the first module is operably coupled to, and in fluid communication with, the internal region of the second flow block via the first fluid passageway thereof, and the second module is operably coupled to, and in fluid communication with, the internal region of the second flow block via the fifth fluid passageway thereof.

18. The MPD manifold of claim 15, wherein the first and second flow blocks each comprise first, second, third, fourth, fifth, and sixth sides, the third, fourth, fifth, and sixth sides extending between the first and second sides, and the first, second, third, fourth, and fifth fluid passageways extending through the first, second, third, fourth, and fifth sides.

19. The MPD manifold of claim 15, wherein the third module further comprises first, second, third, fourth, and fifth valves, the first and second valves being operably coupled to, and in fluid communication with, the first flow block and the respective first and second modules, the third and fourth valves being operably coupled to, and in fluid communication with, the second flow block and the respective first and second modules, and the fifth valve being operably coupled between, and in fluid communication with, the first and second flow blocks.

20. The MPD manifold of claim 13, wherein the second module further comprises first and second flow blocks, and first and second spools, the first spool being operably coupled to, and in fluid communication with, the first flow block, the second spool being operably coupled between, and in fluid communication with, the first and second flow blocks, and the flow meter being operably coupled to, and in fluid communication with, the second flow block.

21. A managed pressure drilling ("MPD") manifold adapted to receive drilling mud from a wellbore, the MPD manifold comprising:
a first flow block into which the drilling mud is adapted to flow from the wellbore;
a second flow block into which the drilling mud is adapted to flow from the first flow block;
a first valve operably coupled to the first and second flow blocks; and a choke module comprising a first drilling choke, the choke module being actuable between:
a backpressure control configuration in which:
the first drilling choke is in fluid communication with the first flow block to control backpressure of the drilling mud within the wellbore;
the second flow block is in fluid communication with the first flow block via the first drilling choke; and the second flow block is not in fluid communication with the first flow block via the first valve;
and a choke bypass configuration in which:
the first drilling choke is not in fluid communication with the first flow block;
the second flow block is not in fluid communication with the first flow block via the first drilling choke; and the second flow block is in fluid communication with the first flow block via the first valve.

22. The MPD manifold of claim 21, further comprising:
a valve module operably coupled to the choke module, the valve module comprising a second valve; and a flow meter module operably coupled to the valve module, the flow meter module comprising a flow meter;
wherein the valve module is actuable between:
a flow metering configuration in which:
the second flow block is in fluid communication with the first flow block via the flow meter; and the second flow block is not in fluid communication with the first flow block via the second valve;
and a meter bypass configuration in which:
the second flow block is not in fluid communication with the first flow block via the flow meter; and the second flow block is in fluid communication with the first flow block via the second valve.

23. The MPD manifold of claim 22, wherein the choke module further comprises a second drilling choke; and wherein the second flow block is adapted to be in fluid communication with the first flow block via one or both of the first drilling choke and the second drilling choke.

24. The MPD manifold of claim 22, wherein the valve module comprises either the first flow block or the second flow block.

25. The MPD manifold of claim 22, wherein the choke module comprises the first flow block and the valve module comprises the second flow block.

26. The MPD manifold of claim 22, wherein the choke module comprises the second flow block and the valve module comprises the first flow block.

27. The MPD manifold of claim 22, wherein the flow meter is a Coriolis flow meter.

28. The MPD manifold of claim 21, wherein the choke module comprises the first valve.

29. The MPD manifold of claim 21, wherein the choke module comprises either the first flow block or the second flow block.

30. The MPD manifold of claim 21, wherein the choke module comprises the first valve, the first flow block, and the second flow block.