WO2021006742A1

WO2021006742A1 - Drilling rig systems and methods

Info

Publication number: WO2021006742A1
Application number: PCT/NO2020/050160
Authority: WO
Inventors: Ellen KOLNES; Roy BIRKELAND; Per Inge RØNSBERG
Original assignee: Mhwirth As
Priority date: 2019-07-11
Filing date: 2020-06-15
Publication date: 2021-01-14
Also published as: GB202016129D0; GB201909941D0; GB2584584A; NO20220020A1; GB2585681B; GB2584584B8; BR112022000212A2; GB2585681A; GB2584584B; GB2584584A8

Abstract

A drilling system (200) comprising a drill floor (7) having a well centre opening (6); a setback (49) for supporting a plurality of vertically stacked pipe strings (33), the setback (49) having a setback surface (30) arranged at a lower elevation than the drill floor (7); a mousehole (35) comprising a side opening (35a) through which a vertically oriented pipe string (33) can be moved horizontally to be placed in or removed from the mousehole (35).

Description

DRILLING RIG SYSTEMS AND METHODS

The present invention relates to systems and methods for drilling rigs, for example such drilling rigs used for offshore petroleum exploration.

BACKGROUND

During drilling operations, for example, drilling carried out for petroleum exploration and exploitation, it is common to handle various tubulars used or installed in a wellbore with the aid of a drilling plant. The drilling plant is commonly arranged at ground level directly above the well or, in the case of offshore wells, on a platform or a floating vessel, such as a semi-submersible rig or a drillship. A variety of operations are carried out during the different stages of well construction, among other things building the drill string, breaking out tubular sections when retrieving the drill string, installation of items at the sea floor and in the well, cementing and fluid circulation, pressure testing, etc.

The drilling plant commonly comprises a dedicated hoisting system for this purpose, usually having a travelling assembly which carries the tubular string and raises or lowers the string and/or items to be installed or retrieved. Such hoisting systems may, for example, be winch-based systems (e.g., using so-called drawworks) with a multiple stringed block, such as is described in WO 2013/076207 A2 and in WO 2014/209131 A1. An alternative solution is a cylinder lifting rig, such as the

RamRig™ technology supplied by the applicant. An example of a possible arrangement is described in WO 97/23705 A1.

Various other machines are also associated with the drilling operation, such as pipe handling machines (see for example GB 2527965), pumps (see for example US 8,186,977), top drives (see for example US 7,743,853), power tongs (see for example US 8,939,048), arrangements for standbuilding (see for example US 9,309,727), and other types of machines and equipment.

Safe and reliable operation is of high importance in such drilling plants. Irregularities in the pipe handling or other processes may, for example, compromise health and safety on the drill floor. Due to the very high operational costs of such plants, efficient operation is also a priority in the industry, with a high focus from technology developers on finding solutions that can improve operational efficiencies. The present disclosure has the objective to provide such improvements, or at least alternatives to conventional technology, in the abovementioned or other areas.

SUMMARY

According to a first aspect of the invention we provide a drilling system comprising: a drill floor having a well centre opening; a setback for supporting a plurality of vertically stacked pipe strings, the setback having a setback surface arranged at a lower elevation than the drill floor; a mousehole arranged on the drill floor and extending downwardly therefrom, the mousehole being configured to receive one or more pipe for building or dismantling a pipe string; wherein the mousehole comprises a side opening through which a vertically oriented pipe string can be moved horizontally to be placed in or removed from the mousehole.

An open area may be provided in the drill floor part of which is above the setback surface, the side opening of the mousehole being connected to the open area.

The drilling system may comprising a vertical pipe handling machine operable to move the pipe string from the mouse hole to the setback or from the setback to the mousehole.

The vertical pipe handling machine may be linearly movable between a position adjacent the setback in which it can be operated to reach a pipe string in the setback and a position adjacent the mousehole in which it can be operated to reach a pipe string in the mousehole.

The pipe handling machine is mounted on tracks supported at least in part above the open area in the drill floor, the pipe handling machine being operable to move along the tracks between the position adjacent the setback and the position adjacent the mousehole.

The open area may have a portion - a well centre channel - which extends from the setback towards the well centre opening.

The drilling system may further comprise a guide arrangement which is operable to guide a pipe string being moved between the setback and the well centre opening along the well centre channel.

According to a second aspect of the invention we provide a hosting system comprising: a vertically arranged hoisting cylinder assembly having exactly three hoisting cylinders, the three hoisting cylinders being horizontally aligned with a second hoisting cylinder arranged between a first and a third hoisting cylinder, at least one sheave arranged in an upper part of the hoisting cylinder assembly; an elongate hoisting member extending from an anchor, via the at least one sheave to a yoke suspended by the hoisting member above a well centre opening in a drill floor; wherein the hoisting system has a first operational configuration wherein all three hoisting cylinders are operable to lift the yoke, a second operational configuration wherein the first and the third hoisting cylinders are operable to lift the yoke while the second hoisting cylinder is idle; and a third operational configuration wherein the second hoisting cylinder is operable to lift the yoke while the first and the third hoisting cylinders are idle.

The hoisting system may comprise a lock mechanism whereby the respective idle hoisting cylinder or cylinders can be held fixed in a contracted state.

The lock mechanism may be a mechanical lock or a hydraulic lock. The respective idle hoisting cylinder or cylinders may be configured to travel together with the yoke without providing a lifting force on the yoke.

According to a third aspect of the invention we provide a method of operating a hosting system comprising a vertically arranged hoisting cylinder assembly having exactly three hoisting cylinders, the three hoisting cylinders being horizontally aligned with a second hoisting cylinder arranged between a first and a third hoisting cylinder, at least one sheave arranged in an upper part of the hoisting cylinder assembly; and an elongate hoisting member extending from an anchor, via the at least one sheave to a yoke suspended by the hoisting member above a well centre opening in a drill floor, the method comprising the steps: in a first operational configuration, operating all three hoisting cylinders to lift the yoke, in a second operational configuration, operating the first and the third hoisting cylinders to lift the yoke while keeping the second hoisting cylinder idle; and in a third operational configuration, operating the second hoisting cylinder to lift the yoke while keeping the first and the third hoisting cylinders idle. BRIEF DESCRIPTION OF THE DRAWINGS

These and other characteristics will become clear from the following description of illustrative embodiments, given as non-restrictive examples, with reference to the attached drawings, in which Figure 1 is a schematic view of a hoisting system according to an embodiment,

Figure 2 is a perspective view of a hoisting system according to an embodiment,

Figure 3 is a perspective view of a hoisting system according to an embodiment,

Figure 4 is a schematic view of a power distribution system for a hoisting system,

Figures 5-11 show various views of a drilling system according to an aspect.

DETAILED DESCRIPTION

The following description may use terms such as“horizontal”,“vertical”,“lateral”, “back and forth”,“up and down”,’’upper”,“lower”,“inner”,“outer”,“forward”,“rear”, etc. These terms generally refer to the views and orientations as shown in the drawings and that are associated with a normal use of the invention. The terms are used for the reader’s convenience only and shall not be limiting.

Figures 1-3 illustrate a hoisting system 100 according to an embodiment. The hoisting system 100 may be suitable for use with, for example, a drilling plant. The hosting system 100 comprises a vertically arranged hoisting cylinder assembly 1 having exactly three hoisting cylinders 1a-c (see Fig. 2). The three hoisting cylinders 1a-c are arranged horizontally aligned in a row, with a second hoisting cylinder 1 b arranged between a first 1a and a third 1c hoisting cylinder. Each hoisting cylinder 1a-c has a cylinder housing which is divided by a piston into a piston side chamber and a rod side chamber. A rod extends from each piston through the rod side chamber and out of the cylinder housing. Each hoisting cylinder is hydraulically operated in the manner known in the art (see, for example, the above-referenced documents).

The rods of each of the cylinders 1a-c carry a sheave assembly 2 having at least one sheave 2a, 2b. The sheave assembly 2 and the sheaves 2a, 2b are arranged in an upper part of the hoisting cylinder assembly 1.

An elongate hoisting member 3, such as a hoisting wire or a plurality of wires, extends from an anchor 5 at a drill floor 7, via the sheaves 2a, 2b to a yoke 4 which is suspended by the hoisting member 3 above a well centre opening 6 in the drill floor 7. The yoke 4 may carry drilling tools, such as a drilling machine 14 (also known as a top drive).

As can be seen in Fig. 3, the cylinder assembly 1 is supported by a rig structure 12, which can also support the other components, such as the sheave assembly 2, through guide rails or the like.

As will be understood by those skilled in the art, a drilling plant may comprise a wide range of other equipment for handling pipes, equipment, fluids, etc., not shown here for clarity.

Fig. 4 illustrates a power distribution system for the hoisting system 100. The three cylinders 1a-c are hydraulically operated, with appropriate hydraulic pipes (not shown here) arranged to the piston side chamber and the rod side chamber of each cylinder 1a-c. A hydraulic controller 10 is operable to control a supply of hydraulic fluid to the hoisting cylinders 1a-c. The hydraulic controller 10 receives pressurized hydraulic fluid from a hydraulic power unit (HPU) 20. An accumulator 21 may be arranged in the circuit to provide temporary energy storage and to smoothen operation. A power management system 22 can be provided, having electronic controllers to optimize operation and ensure reliable power supply to the system. Optionally, a battery energy storage 23 can be provided.

While not illustrated here, it will be clear that the cylinders 1a-c have appropriate return lines and valve arrangements whereby the supply and return lines can be shut off, if required.

According to this embodiment, the hoisting system 100 has a first operational configuration wherein all three hoisting cylinders 1a-c are operable to lift the yoke 4. In this operational configuration, the hoisting cylinders 1a-c all operate to provide a lifting force on the sheave assembly 2. With a given hydraulic supply pressure from the HPU 20, this configuration provides the highest possible lifting force for the system.

The hoisting system 100 further has a second operational configuration wherein the first and the third hoisting cylinders 1a, 1c are operable to apply a lifting force on the sheave assembly 2 to lift the yoke 4 while the second hoisting cylinder 1b is idle. Further, the hoisting system has a third operational configuration wherein the second hoisting cylinder 1b is operable to apply a lifting force on the sheave assembly 2 to lift the yoke 4 while the first and the third hoisting cylinders 1a, 1c are idle.

The respective hoisting cylinders can be put in an idle state in several different ways. For example, a lock mechanism can be employed to lock the cylinder in the contracted state. In this way, the other cylinder or cylinders may lift the sheave assembly 2 while the respective cylinder remains in the contracted (lowermost) position. This may, for example be via a mechanical lock which prevents the cylinder from moving. Alternatively, it may be a hydraulic lock, for example a valve which closes the rod side chamber in the cylinder to prevent the cylinder from operating, or a valve, controlled by the hydraulic controller 10, which shuts off the hydraulic supply from the HPU 20 to the piston side chamber of the respective idle cylinder.

Alternatively, a cylinder 1 a-c may be made idle by other types of hydraulic valve control, for example by connecting the rod side chamber and the piston side chamber of the cylinder with appropriate valves. In this way, the respective idle hoisting cylinder or cylinders can travel together with the sheave assembly 2 without providing a lifting force on the sheave assembly 2. This may be advantageous, for example, if the rods of the cylinders 1a-c are fixed to the sheave assembly 2.

In operating the hoisting system 100, one may thus in the first operational configuration operate all three hoisting cylinders 1a-c to lift the yoke 4, in the second operational configuration operate the first 1a and the third 1c hoisting cylinders to lift the yoke 4 while keeping the second hoisting cylinder 1b idle, and in the third operational configuration operate the second hoisting cylinder 1b to lift the yoke 4 while keeping the first 1a and the third 1c hoisting cylinders idle.

In the different operational configurations the cylinder hoisting assembly can be operated at different capacity and speed. In the first operational configuration, the hoisting system 100 provides the maximum lifting capacity, at a given hoisting speed, determined by the installed capacity of the hydraulic supply system

(particularly, the HPU 20). In the second operational configuration, the hoisting system 100 provides a lower maximum lifting capacity, but a higher lifting speed (with the installed hydraulic capacity provided). In the third operational configuration, the hoisting system 100 provides yet higher lifting speeds, at lower capacity.

Advantageously, a hoisting system 100 and a method according to these

embodiments reduces the structural requirements for the rig structure 12 and/or the hoisting cylinders 1a-c themselves, in that such operational flexibility can be obtained without excessive extra loads on the structure or components between the different operational configurations. For example, the requirement of the rig to take up horizontal loads can be reduced, and the tolerance of the cylinders 1a-c for bending loads can also be relaxed. When fewer than three cylinders are required, by ensuring that either the two outer cylinders 1a, 1c, or only the middle cylinder b are / is used, the lateral or bending forces on the sheave assembly 2 can be minimised.

Accordingly, improved operational flexibility can be achieved without increasing structural design requirements. This may, for example, be useful in drilling plants, in which the hoisting system is required to perform a wide variety of operations, such as heavy lifting at low speeds, and low-load hoisting of, for example, equipment or lighter components,

In another aspect, we provide a drilling system 200, illustrated in Figs 5-11. The drilling system 200 may comprise the hoisting system 100 according to any of the embodiments described above, or it may optionally be used with a different type of hoisting system.

Fig. 5 illustrates an overview of a drilling system 200, for example a drilling system for use on an offshore drilling rig. The drilling rig typically comprises a pipe storage area 201 (for drill pipes, riser segments, etc.) and a drill floor area 202 having a rig (or derrick) structure 12.

With reference to Figs 6-11 , which shows different views and perspectives of the drilling system 200, the drilling system 200 comprises a drill floor 7 having a well centre opening 6. Figs 6-11 shows the same system, however it will be understood that in the different views shown in Figs 6-11 , certain components will in some views have been omitted to aid understanding of the illustrations, and certain components (such as the rig structure 12) may only be shown partly or in a cut view in order that other parts can be more clearly seen.

The drilling system comprises a setback 49 for supporting a plurality of vertically stacked pipe strings 33 (so-called stands).“Pipe strings 33” refer to a string of interconnected pipes as is commonly used in the industry, for example three or four interconnected sections of pipe. The setback 49 has a setback surface 30 for vertically supporting the pipe strings 33 (the lowermost end of each supported pipe string 33 rests on the setback surface 30), and one or more fingerboards 31 ,32 for providing horizontal support of the pipe strings 33 when they are positioned in the setback 49. The setback surface 30 is arranged at a lower elevation than the drill floor 7 (a so-called“reduced setback”), there being an open area 36 in the drill floor 7, part of which is above the setback surface 30, the fingerboards 31 , 32 being arranged vertically above the setback surface 30 and part of the open area 36.

A mousehole 35 (most clearly seen in Figs 8-10) is arranged on the drill floor 7 and extends downwardly therefrom. The mousehole 35 is an opening in the drill floor which, in use, receives one or more pipes during the building or dismantling of a pipe string 33. The mousehole 35 receives so-called“singles” (a single pipe section) from an external storage (such as a pipe deck, not shown). A crane or pipe handling machine is typically provided to feed the singles to the mousehole 35; this may be a dedicated machine or it may be the vertical pipe handling machine 40,41 (or an add on tool to this machine), described in further detail below.

The mousehole 35 typically has an elevating bottom 52 (a so-called“rabbit”; see Fig. 9) which can raise or lower a pipe positioned in the mousehole 35. A tong machine 51 (known as a power tong or iron roughneck) is arranged adjacent the mousehole 35 to assist with making up or breaking out pipe joint connections to build a stand out of several singles. These standard functionalities of a mousehole will be known to the person skilled in the art.

In the prior art, the mousehole 35 is a discrete aperture which simply extends from the uppermost surface of the drill floor 7 all the way through the drill floor 7 to its lowermost surface, and is completely closed around its periphery. As such, vertical movement of a pipe string is required to place the pipe string in the mousehole 35.

In this embodiment, the mousehole 35 extends from the uppermost surface of the drill floor 7 all the way through to the lowermost surface of the drill floor 7 and also has a side opening 35a (see in particular Fig. 8) through which a vertically oriented pipe string 33 can be placed into or removed from the mousehole 35 by horizontal movement of the pipe string 33.

The drilling system may further comprise vertical pipe handling machines 40,41 (see in particular Fig. 6) arranged adjacent the setback 49 and being operable to move the pipe string 33 from the mouse hole 35 to the setback 49 or from the setback to the mouse hole 35.

According to this aspect, a stand (pipe string 33) can be produced from singles provided to the mousehole 35, and then engaged by the pipe handling machine 40,41 and the vertically oriented stand moved horizontally out of the mousehole 35 through the side opening 35a. By connecting the side opening 35a to the open area 36 in the drill floor 7, the pipe handling machine 40,41 may then move the vertically oriented stand substantially horizontally (or with only a minor vertical adjustment) and place it in the setback 49. Consequently, there is no need to lift the stand entirely out of the mousehole 35, i.e. the completed stand will not have to be lifted to an elevation completely above the drill floor 7, in order to move it to the setback 49.

Similarly, when breaking out connections (for example, when tripping out a drill string from the well or removing stands from the setback 49), a vertically oriented stand can be moved into the mousehole 35 by purely or mainly horizontal movement, without the need to lift the stand to an elevation above the drill floor 7.

The drill floor 7 may comprise an edge 37 (see in particular Figs 9 and 10) which surrounds the open area 36, a portion 38 of the edge 37 surrounding a portion of the open area 36 (hereinafter referred to as the mousehole access channel) which extends to the mousehole 35.

In this example, the pipe handling machine(s) 40,41 are linearly movable between a position adjacent the setback 49 in which they can be operated to reach a stand in the setback 49 and a position adjacent the mousehole 35 in which they can be operated to reach a stand in the mousehole 35. This may be achieved by arranging the pipe handling machine(s) 40, 41 to move along tracks 53 (see Fig. 10) which in this example are supported above the open area 36 in the drill floor 7.

The mousehole 35 may be provided with a latch, lock or other blocking mechanism (not shown) across the side opening 35a (fully or partly) in order to hold a pipe in place in the mousehole 35, if required. (I.e., ensure that the pipe does not uncontrollably fall out of the side opening 35a.) Alternatively, this may be achieved by operating other machines (such as a pipe handling machine, a crane feeding pipes to the mousehole 35, the pipe handling machine(s) 40,41 and/or the tong machine 51), to hold the pipe fixed at any point in time.

The another portion 39 (hereinafter referred to as the well centre channel 39) of the open area 36 in the drill floor 7 may extend towards the well centre opening 6. The well centre channel 39 is separate to the mousehole access channel. In this case, the drill system may further comprise a guide arrangement 43,44 (for example, suitable pipe handling machines) for guiding a pipe string 33 being moved between the setback 49 and the well centre opening 6 along the well centre channel 39. Consequently the pipe handling machine(s) 40,41 may pick up a stand in the setback 49, place it in the guide arrangement 43,44, which is then operated to guide the stand along the well centre channel 39 towards the well centre opening 6. The stand may then be lifted above the drill floor 7 for connection with the drill string, for example by means of an elevator arranged in a top drive in the hoisting system associated with the well centre opening 6. Conversely, a stand coming out of the well may be placed in the guide arrangement 43,44 to be picked up and placed in the setback 49.

In this embodiment, the mousehole access channel and the well centre channel 39 are generally parallel to and spaced from one another, and extend from the same side of the open area. In this case, the mousehole access channel and the well centre channel 39 extend from a portion of the edge 37 which is opposite to the setback 49. The well centre channel 39 may be opposite the setback 49. As such, movement of the pipe handling machine(s) 40, 41 between the position adjacent the mousehole 35 and the position adjacent the setback 49 occurs along a line which is generally perpendicular to the direction of movement of a pipe string 33 when transported from the setback 49, along the well centre channel 39 towards the well centre opening 6.

It will be understood that a drilling rig may comprise various other parts and components in addition to those shown in Figs 5-11 , such as a driller’s cabin, various other machines to handle pipes or other equipment, living quarters, etc. The invention is not limited by the embodiments described above; reference should be had to the appended claims.

Claims

1. A drilling system (200) comprising:

a drill floor (7) having a well centre opening (6);

a setback (49) for supporting a plurality of vertically stacked pipe strings (33), the setback (49) having a setback surface (30) arranged at a lower elevation than the drill floor (7);

a mousehole (35) arranged on the drill floor (7) and extending downwardly therethrough, the mousehole (35) being configured to receive one or more pipe for building or dismantling a pipe string (33); wherein the mousehole (35) comprises a side opening (35a) through which a vertically oriented pipe string (33) can be moved horizontally to be placed in or removed from the mousehole (35).

2. A drilling system (200) according to claim 1 wherein an open area is

provided in the drill floor part of which is above the setback surface, the side opening (35a) of the mousehole (35) being connected to the open area.

3. A drilling system according to claim 1 or 2, comprising a vertical pipe

handling machine (40,41) operable to move the pipe string (33) from the mouse hole (35) to the setback or from the setback to the mousehole (35).

4. A drilling system according to claim 3 wherein the vertical pipe handling

machine (40, 41) is linearly movable between a position adjacent the setback (49) in which it can be operated to reach a pipe string (33) in the setback (49) and a position adjacent the mousehole (35) in which it can be operated to reach a pipe string (33) in the mousehole 35.

5. A drilling system according to claim 2 and 4 wherein the pipe handling

machine is mounted on tracks supported at least in part above the open area in the drill floor, the pipe handling machine (40, 41) being operable to move along the tracks (53) between the position adjacent the setback (49) and the position adjacent the mousehole (35).

6. A drilling system according to claim 2 or claim 2 in conjunction with any one of claims 3 to 5, wherein the open area has a portion (39) - for example a well centre channel - which extends from the setback towards the well centre opening.

7. A drilling system according to claim 6 wherein the drilling system further comprises a guide arrangement (43,44) which is operable to guide a pipe string (33) being moved between the setback (49) and the well centre opening (6) along the well centre channel (39).

8. A hosting system (100) comprising:

a vertically arranged hoisting cylinder assembly (1) having exactly three hoisting cylinders (1a-c), the three hoisting cylinders (1a-c) being horizontally aligned, whereby a second hoisting cylinder (1 b) is arranged between a first (1a) and a third (1c) hoisting cylinder,

at least one sheave (2, 2a, 2b) arranged in an upper part of the hoisting cylinder assembly (1);

an elongate hoisting member (3) extending from an anchor (5), via the at least one sheave (2, 2a, 2b) to a yoke (4) suspended by the hoisting member (3) above a well centre opening (6) in a drill floor (7);

wherein the hoisting system (100) has

a first operational configuration wherein all three hoisting cylinders (1a-c) are operable to lift the yoke (4),

a second operational configuration wherein the first (1a) and the third (1c) hoisting cylinders are operable to lift the yoke (4) while the second hoisting cylinder (1b) is idle; and

a third operational configuration wherein the second hoisting cylinder (1b) is operable to lift the yoke (4) while the first (1a) and the third (1c) hoisting cylinders are idle.

9. A hoisting system (100) according to claim 8, comprising a lock mechanism whereby the respective idle hoisting cylinder or cylinders can be held fixed in a contracted state.

10. A hoisting system (100) according to the preceding claim, wherein the lock mechanism is a mechanical lock or a hydraulic lock.

11. A hoisting system (100) according to any one of claims 8-10, wherein the respective idle hoisting cylinder or cylinders is configured to travel together with the yoke (4) without providing a lifting force on the yoke (4).

12. A method of operating a hosting system (100) comprising a vertically

arranged hoisting cylinder assembly (1) having exactly three hoisting cylinders (1a-c), the three hoisting cylinders (1a-c) being horizontally aligned, whereby a second hoisting cylinder (1 b) is arranged between a first (1a) and a third (1c) hoisting cylinder, at least one sheave (2, 2a, 2b) arranged in an upper part of the hoisting cylinder assembly (1); and an elongate hoisting member (3) extending from an anchor (5), via the at least one sheave (2, 2a, 2b) to a yoke (4) suspended by the hoisting member (3) above a well centre opening (6) in a drill floor (7),

the method comprising the steps:

in a first operational configuration, operating all three hoisting cylinders (1a-c) to lift the yoke (4),

in a second operational configuration, operating the first (1a) and the third (1c) hoisting cylinders to lift the yoke (4) while keeping the second hoisting cylinder (1b) idle; and

in a third operational configuration, operating the second hoisting cylinder (1b) to lift the yoke (4) while keeping the first (1a) and the third (1c) hoisting cylinders idle.