GB2611354A

GB2611354A - Mud-shale-gas separator

Info

Publication number: GB2611354A
Application number: GB2114164.3A
Authority: GB
Inventors: Lakhankar Kanti
Original assignee: Kapwell Ltd
Current assignee: Kapwell Ltd
Priority date: 2021-10-04
Filing date: 2021-10-04
Publication date: 2023-04-05
Also published as: GB202114164D0

Abstract

The subject matter disclosed herein relates to improved design of mudshale- gas separator that not only separates the mud, shale cutting and gas from the mixture, but also removes shale cuttings, recovers expensive drilling mud for its reuse and also releases harmful gases. The mud-shalegas separator is comprising of components: a separator main body or an atmospheric vessel; a tangential inlet or mud-shale-gas inlet located approximately at the midpoint of the vertical height of the vessel; a multiple layers of vibrating baffles comprising electric driven vibrator, located in inner cavity of vessel in various shapes; a vent pipe at the top of the vessel; a U-Tube shape pipework configured near to the bottom of the separator vessel; an electric driven Gravity screw conveyor configured at the bottom of the separator to remove shale cutting from the vessel after separation; a Mud inlet port, located between U-tube pipework connection and the bottom of the vessel and a double liquid seal made of gravity screw conveyor and U-shape pipework that prevents uncontrolled escape of poisonous and explosive gas from the vessel. Further, the mud-shale-gas separator of present invention is comprising of a monitoring instruments, an inspection hatch and a maintenance hatch.

Description

TITLE

MUD-SHALE-GAS SEPARATOR:

TECHNICAL FIELD

[0001] The present invention relates to the field of separation of mud, shale and gas in the oil and gas industries. More specifically, it is an apparatus to separate mud, shale and gas in Oil and Gas industries during fracturing, flow-back or testing operations. The mud-shale-gas separator of present invention not just separates the mud, shale and gas but also removes shale cuttings, recovers mud or liquid used while shale gas drilling operations and also safely releases harmful gases.

DESCRIPTION OF RELATED ART

[0002] Traditional Mud Gas Separator do not work well for shale gas drilling operation due to clogging by shale cuttings, and Shale Gas Separators only take care of removal of shale cuttings and release of harmful gases but does not consider reuse of drilling mud. Considering the drilling mud carry out its essential functions for shale gas drilling to avoid borehole instability and its high cost.

[0003] While drilling, there is always possibility of kick, which means sudden increment in return shale gas flow rate and pressure. If the capacity of liquid seal system of separator exceeds, the gases may blow straight through the vessel at the bottom that risks the persons on site and in adjoining area due to uncontrolled escape of explosive and poisonous gas.

[0004] One such system is disclosed in a Patent Number US20140034447A1 having title..Shale-gas separation and cleanout system: which relates to the separation of shale, gas and fluid at a shale-gas well where the shale debris and water from a shale-gas well is tangentially communicated to a vessel where the cyclonic effect within the vessel facilitates the separation of the gas from the shale debris. The separated shale debris and fluid falls to a jet assembly whereby it encounters a jet communicating a fluid therethrough. A venturi provides a motive force to the shale debris and fluid sufficient to propel it into a collection bin. The shale-gas separator of this invention incorporates a fluid bypass overflow line to prevent a buildup of fluid within the vessel.

[0005] Not any prior disclosure teaches about separation apparatus that not only separates mud, shale cutting and gas but also can remove shale cuttings, can recover expensive mud or liquid for reuse and safely release harmful gases, hence there is a need of an apparatus that can overcome the aforesaid need. Further, there exists a need of a separation apparatus that works as a pressure vessel in the event of blockage of separator and the gas vent by shale cuttings, sand or liquid. Moreover, there is a need of a separation apparatus that boosts the speed of separation process and also that does not dilute the expensive mud or liquid keeping it reusable.

SUMMARY

[0006] This summary is provided to introduce a selection of concepts in a simplified form that are further disclosed in a brief description of the invention. This summary is not intended to identify key or essential inventive concepts of the claimed subject matter, nor is it intended for determining the scope of the claimed subject matter.

[0007] The subject matter disclosed herein, teaches about the improved design of mud-shale-gas separator capable of being used in oil and gas industries during drilling and fracturing or flow-back operations. The present invention overcomes all the aforementioned need of an apparatus by providing an improved design of mud-shale-gas separator that not only separates the mud, shale and gas but also removes shale cuttings, recovers the expensive mud or liquid for its reuse and safely vents the harmful gases. Also, the mud-shale-gas separator of present invention boosts the speed of separation, removes stacking of shale cuttings and sand and hence prevents blocking within the vessel as well as decreases use of water to remove stacking and hence prevents dilution of expensive mud or liquid from excessive water.

[0008] The mud-shale-gas separator of present invention is comprising of a main body or separation vessel for separation of mud, gas and shale cutting from mixture returning from drilling and flow-back operations. The separation vessel is vertical cylindrical body which further comprising of multiple layers of vibrating baffles having electric driven vibrator and located in the inner cavity of the vessel, stepped from top to bottom within the vessel. A tangential inlet or mud-shale-gas inlet configured approximately at the midpoint of the vertical height of the cylindrical vessel that routes the returning mixture of mud-shale-gas from drilling process into the vessel which flows downward successively over each vibrating baffles that busts the gas bubble quicker to boost the speed of vent of gas, and also, the vibrating baffles does not allows shale cuttings to stack-up over the baffling plates. Moreover, the vibrating baffling plates allows the mud to be in good shape without use of water which will dilute the mud.

[0009] The mud-shale-gas separator of present invention removes the shale cuttings collected at the bottom of the vessel using the Gravity screw conveyor configured at the bottom of the separator vessel. While, the reusable mud, separated from the mixture in the vessel gets out of the separator using the U-tube pipework configured at upper side of the bottom of the separator that allows overflow of the reusable mud out from the separator into the well fluid tank and a surge pump connected to the well fluid tank whereby it takes suction of clean active mud from the well fluid tank and injects it into the separation vessel for cleaning the shale cuttings therefor avoiding dilution of clean mud to maintain the fluid flow through the U-tube to effectively maintain cuttings flow and flushing. A vent pipe configured at the top of the separator vessel allows the separated toxic and highly flammable gases to evacuate from the separator.

[0010] The mud-shale-gas separator of present invention further comprises a maintenance hatch for manually maintenance of separator, an inspection hatch for manually inspection of vessel and monitoring instruments that automatically monitors real time variation in different quantities within the vessel, such as pressure within the vessel, level of mud or liquid, flow of inlet mixture etc. [0011] The principal objective of the present invention is to provide a mudshale-gas separator that removes the shale cutting, allows vent of gas and most importantly saves the drilling fluid or mud for its reuse.

[0012] While drilling, there is always possibility of kick, which means sudden increment in return shale gas flow rate and pressure. If the capacity of liquid seal system of separator exceeds, the gases may blow straight through the vessel at the bottom. Hence, this is the further objective of the present design of mud-shale-gas separator facilitate double protection by providing a double liquid seal system, via gravity screw conveyor and U-tube liquid seal and also reduces the size of the traditional U-tube for drilling operation where the kick is expected with high flow of gas to the surface thus reducing the risk to person on site and in adjoining areas by preventing uncontrolled escapes of explosive and poisonous gas.

BRIE F DESCRIPTION OF DRAWINGS

[0013] The foregoing summary, as well as the following detailed description of the invention, is better understood when read in conjunction with the appended drawings. For the purpose of mere illustrating of the invention, exemplary constructions of the invention are shown in the drawings. However, the invention is not limited to the specific methods and structures disclosed herein. The description of a method step or a structure referenced by a numeral in a drawing is applicable to the description of that method step or structure shown by that same numeral in any subsequent drawing herein.

[0014] Fig. 1 exemplarily illustrates front view of the improved design of mud-shale-gas separator of one embodiment of present invention.

[0015] Fig, 2 exemplarily illustrates side view of the improved design of mud-shale-gas separator of one embodiment of present invention.

[0016] Fig. 3 exemplarily illustrates isometric view of the improved design of mud-shale-gas separator of one embodiment of present invention.

DETAILED DESCRIPTION OF INVENTION

[0017] The present invention overcomes the aforesaid drawbacks of the above and other objects, features and advantages of the present invention will now be described in greater detail. Also, the following description includes various specific details and are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that: without departing from the scope and spirit of the present disclosure and its various embodiments there may be any number of changes and modifications described herein.

[0018] The present embodiment of the invention discloses an improved design of mud-shale-gas separator used in oil and gas industries in processes such as fracturing or flow-back or drilling operation to separate mud, shale cutting and toxic gas from the return mixture in drilling operation. Further, the improved design of mud-shale-gas separator of present invention, not only separates the mud, shale cutting and gas from the mixture, but also removes shale cuttings, recovers expensive drilling mud for its reuse and also releases harmful gases. According to present embodiment, the mud-shale-gas separator is comprising of components: a separator main body or an atmospheric vessel; a tangential inlet or mud-shale-gas inlet located approximately at the midpoint of the vertical height of the vessel; a multiple layers of vibrating baffles comprising electric driven vibrator, located in inner cavity of vessel in various shapes; a vent pipe at the top of the vessel; a U-Tube shape pipework configured near to the bottom of the separator vessel; an electric driven Gravity screw conveyor configured at the bottom of the separator to remove shale cutting from the vessel after separation; a Mud inlet port, located between U-tube pipework connection and the bottom of the vessel; a sparge pump connected to the well fluid tank and a mud inlet of the separation vessel and a double liquid seal made of gravity screw conveyor and U-shape pipework that prevents uncontrolled escape of poisonous and explosive gas from the vessel. Further, the mud-shale-gas separator of present invention is comprising of a monitoring instruments, an inspection hatch and a maintenance hatch.

[0019] Now referring to Fig. 1 which exemplarily illustrates one embodiment of mud-shale-gas separator 100 of present invention which consists of vertical cylindrical main body or separation vessel 102 for separation of drilling mixture of mud, shale and gas coming back from the drilling process in oil and gas industries. The Drilling mixture enters into the vessel 102 of the separator 100 through the mixture or shale-mud-gas inlet pipe 104 located at the midpoint of the vertical height of cylindrical vessel 102 that provides the top half of a vessel 102 for a gas chamber and remaining bottom half for gas separation and fluid retention. The separator 100 of the present embodiment, as mentioned earlier, comprises series of multiple layer of vibrating baffle (not shown) having electric driven vibrator located in the inner cavity of the vessel 102, stepped from the top to the bottom. When the mud-shale-gas mixture is routed into the vessel 102 from the inlet 104, it flows downward successively over each specially designed vibrating baffle plates (not shown) that boosts the gas separation process from the mixture.

[0020] A vent Pipe 108 configured over the top of the vessel 102 of separator 100 that evacuates the relieved toxic and highly inflammable gases from mud and shale cutting. The shale cutting and sand from the separation gets deposited at the bottom of the vessel 102 which gets removed from the vessel 102 using the electric driven Gravity driven screw conveyor 110 configured at the bottom of the vessel 102. The U-tube pipework 112 configured near to the bottom of the vessel 102 allows discharging of mud into the well fluid tank (not shown) when level of mud overflows the level of U-tube pipework 112. Further, the sparge pump 106 configured and connected to the well fluid tank whereby the said sparge pump 106 takes suction of clean active mud from the tank and injects it into the separation vessel 102 for cleaning the shale cuttings and hence avoiding dilution of the clean mud to maintain fluid flow through the U-tube to effectively maintain cuttings flow and flushing.

[0021] According to present embodiment, the vessel 102 of the separator 100 further comprises maintenance hatch 114 to manually maintenance of the vessel 102 and an inspection hatch 116 that allows manual inspection of vessel 102 by a person. Further, the separator 100 of the present invention comprises of additional monitoring instruments that allows automatic mentoring of various quantities such as pressure within the vessel 102, level of mud etc. within the vessel 102.

[0022] Further, the Gravity Screw Conveyor 110 together with the U-Tube pipework 112 provides double liquid seal protection in ensuring safe passage of harmful gas and prevents straight blow of gases through the bottom of the vessel in situation of kick, in which flow rate and pressure of returning mixture from drilling increase suddenly and rapidly.

[0023] Fig. 2 and Fig. 3 which respectively shows side view and isometric view of the improved design of mud-shale-gas separator of present embodiment of the invention. The vibrating baffle of the present embodiment of the separator 100 boosts the process of gas separation from the mud and shale cutting. Further, as the baffles are vibrating, it doesn't allow stacking of shale cutting over baffles and hence reduced additional requirement of use of water to remove stacking, which generally dilutes the mud and makes it useless. The main purpose of the mud-shale-gas separator of present invention is to vent the gas and save the drilling fluid which is important to minimize the risk of circulating out a gas kick without having to shut down to mix additional mud volume.

Claims

Claims, 1. The mud-shale-gas separator to separate and remove shale cuttings, to recovers mud or liquid used in drilling operations and to safely release harmful gases comprising of: a separator main body or separator vessel; a multiple layers of vibrating baffles located within the separator vessel, stepped from top to bottom within the separator vessel; a tangential inlet configured at the midpoint of the separator vessel to route the mud-shale-gas mixture from drilling operation into the separation vessel; a vent pipe configured at the top of the separator vessel to evacuate toxic and flammable gases from the separator vessel; an Gravity screw conveyor configured at the bottom of the separator vessel to remove shale cutting collected at the bottom of the separation vessel; a U-tube pipework configured at upper side of the bottom of the separator vessel to allow overflow of the mud or liquid out from the separator vessel; and a sparge pump configured to suck clean active mud and reinject it to the vessel for cleaning the shale cutting and to maintain fluid flow through the U-tube to effectively maintain cuttings flow and flushing.
2. The mud-shale-gas separator of claim 1, wherein the separator further comprises a maintenance hatch for manually maintenance of separator, an inspection hatch for manually inspection of vessel and monitoring instruments that automatically monitors real time variation in different quantities within the vessel.
3. The mud-shale-gas separator of claim 1, wherein the separation vessel have vertical cylindrical body.
4. The mud-shale-gas separator of claim 1, wherein the vibrating baffles comprises baffle plates and electric driven vibrator attached to baffle plates to allow vibration of baffles.
5. The mud-shale-gas separator of claim 1, wherein the gravity screw conveyor is any of electric, hydraulic or pneumatic driven.