CN111927398B

CN111927398B - Coal bed gas production system and gas production method

Info

Publication number: CN111927398B
Application number: CN201910394202.1A
Authority: CN
Inventors: 李志广; 李风涛; 耿昊; 闫永维; 薛清祥; 刘凯; 窦同伟; 马勇; 郭智栋; 张子佳; 刘印华; 李川; 陈冬
Original assignee: Petrochina Co Ltd; Petrochina Coalbed Methane Co Ltd
Current assignee: Petrochina Co Ltd; Petrochina Coalbed Methane Co Ltd
Priority date: 2019-05-13
Filing date: 2019-05-13
Publication date: 2022-08-30
Anticipated expiration: 2039-05-13
Also published as: CN111927398A

Abstract

The application discloses a coal bed gas production system and a coal bed gas production method, and belongs to the technical field of coal bed gas production. In this application, through power fluid drive piston, when the piston upward movement, the piston drives the second plunger upward movement, and when the second plunger upward movement, the production liquid in coal bed gas shaft bottom enters into the second pump section of thick bamboo, and then enters into in second plunger and the piston, enters into the inner space of the second oil pipe cluster on two pass through liquid nipple joint upper portions through producing the liquid passageway at last. Because the oil pumping rod is not arranged in the gas production system, and the power liquid drives the piston to further enable the produced liquid at the bottom of the coal bed methane well to flow to the ground, the problem that the oil pumping rod and the second oil pipe string are mutually abraded in the related technology is solved. Moreover, because the sucker rod and the second oil pipe string are not mutually abraded in the application, the rodless pump mining system does not need to be stopped, so that the mining of the coal bed gas is not interrupted, and the efficiency of mining the coal bed gas can be improved.

Description

Coal bed gas production system and gas production method

Technical Field

The application relates to the technical field of coal bed gas exploitation, in particular to a coal bed gas exploitation system and a coal bed gas exploitation method.

Background

Coal bed gas has been widely accepted as a clean energy source. And the coal bed gas is stored in the coal bed gas well, so the coal bed gas in the coal bed needs to be exploited by using a coal bed gas exploitation system, and the requirement of people on clean energy is met.

In the related art, a sucker rod pump gas production system is used for mining coal bed gas. As shown in fig. 1, the sucker-rod pump gas production system comprises a first casing string 01, a first tubing string 02, a sucker rod 03 and a sucker-rod pump 04. The first casing string 01 is located in a coal-bed gas well, the first oil pipe string 02 is located in the first casing string, and the outer diameter of the first oil pipe string 02 is smaller than the inner diameter of the first casing string 01, so that an annular space is formed between the first casing string 01 and the first oil pipe string 02. Sucker rod 03 and sucker rod 04 all are located first oil pipe cluster 02, and sucker rod 03 is connected with sucker rod 04. Therein, the rod pump 04 comprises a first pump barrel 041, a first plunger 042, a traveling valve 043, a traveling valve housing 044, and a fixed valve 045. First plunger 042 is located between the first end and the second end of first cylinder 041, traveling valve 043 is located on first plunger 042, traveling valve housing 044 is connected to sucker rod 03, and fixed valve 045 is located at the second end of first cylinder 041. When the sucker rod pump gas production system is used for producing coal bed gas, the sucker rod drives the traveling valve cover to reciprocate up and down, and the traveling valve cover drives the first plunger to reciprocate up and down. When the first plunger moves upwards, the fixed valve is opened, and water in the coal-bed gas well enters the first pump cylinder. When the first plunger moves downwards, the traveling valve is opened, and water in the first pump cylinder enters the first oil pipe string and is conveyed to the ground through the first oil pipe string. In the process of conveying water in the coal-bed gas well to the ground, the coal-bed gas in the coal-bed gas well is conveyed to the ground through an annular space between the oil rod string and the first casing string.

Coal bed gas wells are typically deep and the well bore of a coal bed gas well is typically not vertical to the surface. That is, the wellbore of the coal bed gas well has a slope, which causes the first casing string and the first tubing string to have a slope with the wellbore. The sucker rod in the sucker-rod pump gas production system in the related art is vertical to the ground, so that the phenomenon that the sucker rod and the first oil pipe string are mutually abraded occurs in the process of up-and-down reciprocating motion of the sucker rod. After the sucker rod and the first tubing string are seriously worn, the operation of the sucker rod pump mining system needs to be stopped so as to replace the sucker rod, thereby affecting the efficiency of mining coal bed gas.

Disclosure of Invention

The embodiment of the application provides a system and a method for producing coal bed gas, which can improve the efficiency of the coal bed gas. The technical scheme is as follows:

in one aspect, a coal bed gas production system is provided, which comprises a ground system and a downhole system;

the ground system comprises a power pump, a first energy accumulator and a reversing mechanism, wherein the power pump and the first energy accumulator are connected with a first end of the reversing mechanism;

the underground system comprises a casing string, an oil pipe string, a double-pass liquid nipple, a hydraulic cylinder, a piston, a plunger and a pump cylinder, wherein the oil pipe string is nested in the casing string, and the double-pass liquid nipple, the hydraulic cylinder, the piston, the plunger and the pump cylinder are all positioned in the oil pipe string;

the double-passage liquid nipple comprises a power liquid channel and a liquid production channel, a first port of the power liquid channel and a first port of the liquid production channel are both positioned at a first end port of the double-passage liquid nipple, a second port of the power liquid channel is positioned on a side wall of the double-passage liquid nipple, a second port of the liquid production channel is positioned at a second end port of the double-passage liquid nipple, and the side wall of the first end of the double-passage liquid nipple is in sealing connection with the oil pipe string;

a port of a second end of the reversing mechanism is communicated with a first port of the power fluid channel, a second port of the fluid production channel is communicated with a port of a first end of the hydraulic cylinder, a port of a second end of the hydraulic cylinder is communicated with a port of a first end of the pump cylinder, a through hole is formed in the side wall of the second end of the hydraulic cylinder, and the side wall of the first end of the pump cylinder is in sealing connection with the oil pipe string;

the plunger with the piston is hollow structure, the piston is located in the hydraulic cylinder, just the outer wall of piston with the inner wall contact of hydraulic cylinder, the port position department of the first end of piston has deployed the liquid outlet, the port of the second end of piston with the port intercommunication of the first end of plunger, the second end of plunger is located in the pump barrel, just the port position department of the second end of plunger with the port position department of the second end of pump barrel has all deployed the feed liquor valve.

Optionally, the surface system further comprises a power fluid pool;

the power liquid pool is connected with a first end of the power pump, and a second end of the power pump is connected with a first interface of the reversing mechanism, so that the power pump can pump power liquid in the power liquid pool and convey the power liquid to the double-passage liquid nipple through the first interface;

the power liquid pool is also connected with a second interface of the reversing mechanism, so that the reversing mechanism can convey the power liquid returned by the double-passage liquid nipple to the power liquid pool.

Optionally, the surface system further comprises a second accumulator, a pressure limiting valve and a fluid producing pool;

the first end of the pressure limiting valve and the second energy accumulator are both connected with the liquid production outlet end of the oil pipe string, and the second end of the pressure limiting valve is connected with the liquid production pool.

Optionally, the downhole system further comprises a liquid outlet valve located at a liquid outlet position at the first end of the piston.

Optionally, the downhole system further comprises a first seal sub;

the first sealing short section is positioned between the side wall of the first end of the double-passing liquid short section and the oil pipe string, so that the side wall of the first end of the double-passing liquid short section is in sealing connection with the oil pipe string.

Optionally, the downhole system further comprises a second sealing sub;

the second sealing short section is located between the side wall of the first end of the pump cylinder and the oil pipe string, so that the side wall of the first end of the pump cylinder is in sealing connection with the oil pipe string.

Optionally, the downhole system further comprises a hollow rod;

the first end of the hollow rod is connected with the second end of the reversing mechanism, and the port of the second end of the hollow rod is communicated with the first port of the power fluid channel.

In another aspect, a coal bed gas production method is provided, and is applied to any one of the coal bed gas production systems in the first aspect, and the method includes:

controlling the power pump to be in a working state;

and controlling the first interface and the second interface of the reversing mechanism to be in a working state alternately so as to drive the piston to move up and down through power fluid.

Optionally, the method further comprises:

when the coal-bed gas well needs to be cleaned, the first interface of the reversing mechanism is controlled to be kept in a communication state with the power pump, so that the reversing mechanism injects power fluid into the first port of the power fluid channel, the power fluid drives the piston to move upwards, the plunger is no longer located in the pump cylinder, and the coal-bed gas well is cleaned through the power fluid.

Optionally, the method further comprises:

and when the daily gas production of the coal-bed gas well is greater than the daily gas production threshold, driving the double-passing liquid short section to move upwards so as to communicate the space at the lower part of the sealing position of the pump cylinder and the oil pipe string and the space at the upper part of the sealing position of the double-passing liquid short section and the oil pipe string.

In another aspect, a coal bed gas production device is provided, the device includes:

the first control module is used for controlling the power pump to be in a working state;

and the second control module is used for controlling the first interface and the second interface of the reversing mechanism to be in a working state alternately so as to drive the piston to move up and down through power liquid.

Optionally, the apparatus further comprises:

and the third control module is used for controlling the first interface of the reversing mechanism to keep a communication state with the power pump when the coal-bed gas well needs to be cleaned, so that the reversing mechanism injects power liquid into the first port of the power liquid channel, the piston is driven by the power liquid to move upwards, the second piston is no longer positioned in the second pump cylinder, and the coal-bed gas well is cleaned through the power liquid.

Optionally, the apparatus further comprises:

and the driving module is used for driving the double-passing liquid short section to move upwards when the daily gas production of the coal-bed gas well is greater than a daily gas production threshold value, so that the space at the lower part of the sealing position of the second pump cylinder and the second oil pipe string is communicated with the space at the upper part of the sealing position of the second oil pipe string through the double-passing liquid short section.

In another aspect, a coal bed gas production apparatus is provided, the apparatus comprising:

a processor;

a memory for storing processor-executable instructions;

wherein the processor is configured to perform the steps of any of the above described methods for coal bed methane gas production.

In a fourth aspect, a computer readable storage medium has instructions stored thereon, which when executed by a processor, implement the steps of any of the methods for producing coal bed methane.

In a fifth aspect, there is provided a computer program product comprising instructions which, when run on a computer, cause the computer to perform the steps of any of the above described methods of coal bed gas production.

The technical scheme provided by the embodiment of the application has the following beneficial effects:

in this application, through power fluid drive piston, when the piston upward movement, the piston drives the second plunger upward movement, and when the second plunger upward movement, the production liquid in coal bed gas shaft bottom enters into the second pump section of thick bamboo, and then enters into in second plunger and the piston, enters into the inner space of the second oil pipe cluster on two pass through liquid nipple joint upper portions through producing the liquid passageway at last. Because the pumping rod is not arranged in the gas production system, and the piston is driven by the power fluid to enable the produced fluid at the bottom of the coal bed gas well to flow to the ground, the problem that the pumping rod and the second oil pipe string are mutually abraded in the related technology is solved. Moreover, because the sucker rod and the second oil pipe string are not mutually abraded in the application, the rodless pump mining system does not need to be stopped, so that the mining of the coal bed gas is not interrupted, and the efficiency of mining the coal bed gas can be improved.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the description below are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings without creative efforts.

Fig. 1 is a schematic structural diagram of a gas production system of a sucker-rod pump provided in the related art;

FIG. 2 is a schematic structural diagram of a coal bed methane gas production system provided in an embodiment of the present application;

FIG. 3 is a schematic structural diagram of another coalbed methane gas production system provided by the embodiment of the application;

FIG. 4 is a flow chart of a method for producing coal bed methane according to an embodiment of the present disclosure;

FIG. 5 is a schematic structural diagram of another coalbed methane gas production system provided by the embodiment of the present application;

FIG. 6 is a schematic structural diagram of another coalbed methane gas production system provided by the embodiment of the present application;

FIG. 7 is a schematic structural diagram of a coalbed methane gas production device provided by an embodiment of the present application;

fig. 8 is a block diagram of a terminal according to an embodiment of the present disclosure.

Reference numerals are as follows:

01: a first casing string; 02: a second tubing string; 03: a sucker rod; 04: a sucker-rod pump; 041: a first pump barrel; 042: a first plunger; 043: a traveling valve; 044: a traveling valve cover; 045: a fixed valve;

10: a ground system; 20: a downhole system; 101: a power pump; 102: a first accumulator; 103: a reversing mechanism; 104: a power liquid pool; 105: a second accumulator; 106: a pressure limiting valve; 107: a liquid production pool; 201: a second casing string; 202: a second tubing string; 203: a double-pass liquid nipple; 204: a hydraulic cylinder; 205: a piston; 206: a second plunger; 207: a second pump barrel; 208: a liquid inlet valve; 209: a liquid outlet valve; 210: a first sealing nipple; 211: a second sealing short section; 212: a hollow shaft; 2031: a power fluid passage; 2032: a fluid production channel.

Detailed Description

To make the objects, technical solutions and advantages of the present application more clear, embodiments of the present application will be described in further detail below with reference to the accompanying drawings.

Fig. 2 is a schematic structural diagram of a coal bed methane gas production system according to an embodiment of the present application. As shown in fig. 2, the coal bed gas production system includes: a surface system 10 and a downhole system 20.

The ground system 10 comprises a power pump 101, a first accumulator 102 and a reversing mechanism 103, wherein the power pump 101 and the first accumulator 102 are connected with a first end of the reversing mechanism 103. The downhole system 20 comprises a second tubing string 201, a second tubing string 202, a dual-pass hydraulic sub 203, a hydraulic cylinder 204, a piston 205, a second plunger 206 and a second pump cylinder 207, wherein the second tubing string 202 is nested in the second tubing string 201, and the dual-pass hydraulic sub 203, the hydraulic cylinder 204, the piston 205, the second plunger 206 and the second pump cylinder 207 are all located in the second tubing string 201.

The dual-passage liquid nipple 203 comprises a power liquid channel 2031 and a liquid production channel 2032, a first port of the power liquid channel 2031 and a first port of the liquid production channel 2032 are both located at a first end port of the dual-passage liquid nipple 203, a second port of the power liquid channel 2031 is located on a side wall of the dual-passage liquid nipple 203, a second port of the liquid production channel 2032 is located at a second end port of the dual-passage liquid nipple 203, and a side wall of a first end of the dual-passage liquid nipple 203 is in sealing connection with the second oil pipe string 202.

The port of the second end of the reversing mechanism 103 is communicated with the first port of the power fluid channel 2031, the second port of the fluid production channel 2032 is communicated with the port of the first end of the hydraulic cylinder 204, the port of the second end of the hydraulic cylinder 204 is communicated with the port of the first end of the second pump barrel 207, a through hole is formed in the side wall of the second end of the hydraulic cylinder 204, and the side wall of the first end of the second pump barrel 207 is hermetically connected with the second oil pipe string 202.

The second plunger 206 and the piston 205 are both hollow structures, the piston 205 is located in the hydraulic cylinder 204, the outer wall of the piston 205 is in contact with the inner wall of the hydraulic cylinder 204, a liquid outlet is disposed at a port position of a first end of the piston 205, a port of a second end of the piston 205 is communicated with a port of the first end of the second plunger 206, a second end of the second plunger 206 is located in the second pump cylinder 207, and a liquid inlet valve 208 is disposed at a port position of the second end of the second plunger 206 and a port position of the second end of the second pump cylinder 207.

When the rodless pump gas production system provided by the embodiment of the application is used, power fluid is injected into the first port of the power fluid channel through the power pump, the energy accumulator and the reversing mechanism, and then the power fluid flows out of the second port of the power fluid channel. Because the side wall of the second end of the hydraulic cylinder is provided with the through hole, the power liquid enters the hydraulic cylinder through the through hole. Because the outer wall of the piston is in contact with the inner wall of the hydraulic cylinder, the power liquid can drive the piston to move after entering the hydraulic cylinder. And the side wall of the first end of the double-liquid passing nipple is in sealing connection with the second oil pipe string, and the side wall of the first end of the second pump cylinder is in sealing connection with the second oil pipe string, so that the produced liquid at the bottom of the coal bed methane well can only flow into the second pump cylinder.

Because the port position department of the second end of second plunger and the port position department of the second end of second pump cylinder all dispose the feed liquor valve, consequently, after power liquid got into the hydraulic cylinder, power liquid drove the piston upward movement, and the piston drives the second plunger upward movement, and the product liquid in the coal bed methane well bottom gets into in the second pump cylinder through the feed liquor valve of the port position department of the second end of second pump cylinder, and then gets into in the second plunger through the feed liquor valve of the port position department of the second end of second plunger. Since the port of the first end of the second plunger communicates with the port of the second end of the piston, the production fluid in the second plunger can enter the piston. Because the port position of the first end of the piston is provided with the liquid outlet, the produced liquid entering the piston can flow out of the piston and enter the liquid cylinder. Because the second port of the liquid production channel is communicated with the port of the first end of the hydraulic cylinder, the produced liquid entering the hydraulic cylinder flows into the inner space of the second oil pipe string passing through the upper part of the liquid passing nipple through the liquid production channel, and the produced liquid is conveyed to the ground through the second oil pipe string. When the produced liquid in the coal bed gas well enters the second pump barrel, the coal bed gas in the coal bed gas well is conveyed to the ground through the space between the second oil pipe string and the second sleeve string.

That is, in this application embodiment, drive the piston through power fluid, when the piston upward movement, the piston drives the second piston upward movement, and when the second piston upward movement, the production liquid in coal bed methane shaft bottom enters into the second pump section of thick bamboo, and then enters into in second piston and the piston, enters into the inner space of the second oil pipe cluster of two passing liquid nipple upper portions through production liquid passageway 2032 at last. Because the pumping rod is not arranged in the gas production system, and the piston is driven by the power fluid to enable the produced fluid at the bottom of the coal bed gas well to flow to the ground, the problem that the pumping rod and the second oil pipe string are mutually abraded in the related technology is solved. Moreover, because the sucker rod and the second oil pipe string are not mutually abraded in the application, the rodless pump mining system does not need to be stopped, so that the mining of the coal bed gas is not interrupted, and the efficiency of mining the coal bed gas can be improved.

In addition, in some embodiments, the reversing mechanism 103 includes a first interface and a second interface, the first interface corresponds to the first channel, and the second interface corresponds to the second channel, and when the reversing mechanism 103 is in operation, the first channel and the second channel in the reversing mechanism 103 can be alternately opened to allow the power fluid to flow through the first channel or the second channel.

In order to enable the power pump 101 to intensively pump the power fluid when using the coal bed methane gas production system provided by the embodiment of the present application, the surface system 10 may include a power fluid pool 104. The power liquid pool 104 is connected with a first end of the power pump 101, a second end of the power pump 101 is connected with a first connector of the reversing mechanism 103, so that the power pump 101 can pump power liquid in the power liquid pool 104 and convey the power liquid to the double-pass liquid nipple 203 through the first connector. The power liquid pool 104 is also connected with a second interface of the reversing mechanism 103, so that the reversing mechanism 103 can convey the power liquid returning through the liquid nipple 203 to the power liquid pool 104.

As shown in fig. 3, the power pump 101, the first accumulator 102, and the reversing mechanism 103 are all in an operating state, and the power pump 101 draws power fluid from the power fluid pool into the power pump 101. The first accumulator 103 stores therein energy of the power fluid. The energy of the power fluid stored in the first energy accumulator refers to the energy carried by the power fluid and converted into compression energy or potential energy after the power fluid with certain pressure enters the first energy accumulator.

If the first channel in the reversing structure 103 is opened and the second channel is closed, at this time, the power fluid in the power pump 101 and the power fluid stored in the first accumulator 102 enter the first port of the power fluid channel 2031 of the two-way liquid passing nipple 203, and flow out from the second port of the power fluid channel 2031, and then enter the hydraulic cylinder 204. The power fluid entering the hydraulic cylinder 204 drives the piston 205 upward, and the piston 205 drives the second plunger 206 upward. When the second plunger 206 moves upwards, the liquid inlet valve 208 at the second end of the second pump cylinder 207 is opened, and the produced liquid at the bottom of the coal bed methane well enters the second pump cylinder 207. After the production fluid enters the second cylinder 207, the inlet valve 208 at the second end port of the second plunger opens and the production fluid enters the second plunger 206 and thus the piston 205. After production fluid enters piston 205, production fluid exits piston 205 through production fluid passage 2032 into the interior space of second tubing string 202 double through the upper portion of fluid nipple 203.

If the second channel in the switch structure 103 is open, the first channel is closed. At this time, the power pump 101 pumps the sucked power fluid into the first accumulator 102, and the piston 205 moves downward. When the piston 205 moves downward, the power fluid entering the hydraulic cylinder 204 flows out of the hydraulic cylinder 204, along the second port of the power fluid channel 2031 to the first port of the power fluid channel 2031, into the reversing mechanism 103, through the second channel in the reversing mechanism 103 to the second port of the reversing mechanism 103, and finally into the power fluid reservoir. When the first passage in the reversing mechanism 103 is opened and the second passage is closed, the power fluid passes through the power pump 101, the first accumulator 102 and the reversing mechanism 103 again into the hydraulic cylinder, so that the piston 205 moves upward. The first passage and the second passage of the reversing mechanism 103 are alternately opened, so that the piston 205 in the hydraulic cylinder 204 reciprocates up and down. Power fluid also circulates through the reversing mechanism 103, the two-way fluid nipple 203, and the hydraulic cylinder 204.

When the second passage of the reversing mechanism 103 is opened, the power fluid finally flows into the power fluid pool from the fluid cylinder, and at this time, the power fluid can be generally called spent power fluid.

In addition, the connection mode of the power liquid pool 104 and the first end of the power pump 101 can be as follows: a first pipeline is arranged between the first end of the power pump 101 and the power liquid pool 104, the first end of the power pump 101 is connected with the first end of the first pipeline, and the second end of the first pipeline extends to the position below the liquid level of the power liquid in the power liquid pool 104. In this way the power fluid 104 is connected to the first end of the power pump 101.

Of course, the connection mode of the power liquid pool 104 and the first end of the power pump 101 may also have other connection modes, and the embodiment of the present application is not limited herein.

In addition, the connection mode of the second end of the power pump 101 and the first interface of the reversing mechanism 103 may be: a second pipeline is arranged between the second end of the power pump 101 and the first interface of the reversing mechanism 103, the second end of the power pump 101 is connected with the first end of the second pipeline, and the second end of the second pipeline is connected with the first interface of the reversing mechanism 103.

In this case, the connection mode of the power pump 101 and the first accumulator 102 to the first end of the reversing mechanism 103 may be: the second end of the power pump 101 is connected to the first port of the reversing structure 103 through a second pipe, and a through hole is formed in the second pipe at a position between the first end and the second end, the through hole is connected to the first end of a third pipe, and the second end of the third pipe is connected to the first accumulator 102.

In addition, the connection manner of the power liquid pool 104 and the second interface of the reversing mechanism 103 may refer to the connection manner of the power liquid pool 104 and the first end of the power pump 101, and is not described herein again.

It should be noted that fig. 2 shows a state of the piston when the piston moves downward, and fig. 3 shows a state of the piston when the piston moves upward.

In addition, in order to facilitate the downward movement of the piston when using the coal bed methane gas production system provided by the embodiment of the present application, as shown in fig. 2, the surface system 10 may include a second accumulator 105, a pressure limiting valve 106 and a liquid production tank 107. The first end of the pressure limiting valve 106 and the second accumulator 105 are both connected with the produced fluid outlet end of the second tubing string 202, and the second end of the pressure limiting valve 106 is connected with the produced fluid reservoir 107.

It should be noted that the pressure limiting valve 106 has a pressure threshold, and when the pressure to be applied to the pressure limiting valve 106 by the fluid passing through the pressure limiting valve 106 is greater than the pressure threshold, the pressure limiting valve opens to allow fluid to flow through the pressure limiting valve 106. When the surface system 10 includes the second accumulator 105, the pressure limiting valve 106 and the fluid producing reservoir 107, after the piston 205 moves upward, the produced fluid at the bottom of the coalbed methane well flows into the inner space of the second tubing string at the upper part of the two-way flow nipple 203 through the fluid producing passage 2032, and then the produced fluid continues to move upward along the second tubing string 202 until it flows to the fluid producing outlet end of the second tubing string 202. Production fluid will flow into the second accumulator 105 and also towards the pressure limiting valve 106.

When the pressure of the production fluid is less than the pressure threshold of the pressure limiting valve 106, the pressure limiting valve 106 will block the production fluid so that the production fluid will not continue to flow through the pressure limiting valve 106. At this time, the production fluid flows entirely into the second accumulator 105. The second accumulator 105 stores energy of the produced fluids. When the second passage in the reversing mechanism 103 is open, and production fluid is no longer flowing into the second pump barrel 207, the second accumulator 105 releases the stored energy of the production fluid, which causes the piston 205 to move downward. When the piston 205 moves downward, power fluid flows from the cylinder 204, through the power fluid passage 2031 and the second passage of the reversing mechanism 103, and into the power fluid sump. The energy of the produced fluid released by the second accumulator 105 is referred to as wellhead back pressure, and the energy of the produced fluid released by the second accumulator 105 to move the piston 205 downward is referred to as moving the piston 205 downward under the action of wellhead back pressure.

Additionally, in some embodiments, the connection of the first end of the pressure limiting valve 106, the second accumulator 105, and the production fluid outlet end of the second tubing string 202 may be: a fourth pipe is placed between the first end of the pressure limiting valve 106 and the produced fluid outlet end of the second tubing string 202, the first end of the fourth pipe is connected with the produced fluid outlet end of the second tubing string 202, and the second end of the fourth pipe is connected with the first end of the pressure limiting valve 106. And a through hole is formed in the pipe wall between the first end and the second end of the fourth pipeline. A fifth pipe is placed between the through hole and the second accumulator 105, a first end of the fifth pipe is connected with the through hole, and a second end of the fifth pipe is connected with the second accumulator 105. In this way, the first end of the pressure limiting valve 106, the second accumulator 105 are both connected with the production fluid outlet end of the second tubing string 202.

Of course, the connection mode of the first end of the pressure limiting valve 106 and the second accumulator 105 both connected to the produced fluid outlet end of the second tubing string 202 may have other modes, and the embodiment of the present application is not limited herein.

Additionally, in some embodiments, the connection of the second end of the pressure limiting valve 106 to the production reservoir 107 may be: a sixth pipeline is arranged between the second end of the pressure limiting valve 106 and the liquid production pool 107, the first end of the sixth pipeline is connected with the second end of the pressure limiting valve 106, and the second end of the sixth pipeline is arranged in the liquid production pool 107.

Of course, the second end of the pressure limiting valve 106 may be connected to the liquid producing tank 107 in other manners, and the embodiment of the present application is not limited herein.

In addition, in order to provide better sealing of the piston when using the coal bed methane gas production system provided by the present application, as shown in fig. 2, the downhole system 20 may include a liquid outlet valve 209, and the liquid outlet valve 209 is located at a liquid outlet position at the first end of the piston 205.

When the piston 205 moves upward, production fluid at the bottom of the coal bed methane well enters the second cylinder 208 through the intake valve 208 at the port at the second end of the second cylinder 207, then enters the second plunger 206 through the intake valve 208 at the port at the second end of the second plunger 206, and then enters the piston 205. After production fluid enters piston 205, outlet valve 209 at the outlet location at the first end of piston 205 is opened and production fluid exits piston 205 and then flows through production fluid passage 2032 into the interior space of second tubing string 202 above dual-pass fluid sub 203.

It should be noted that, in the coal bed gas production system provided by the present application, the downhole system may further include two liquid inlet valve covers and one liquid outlet valve cover. One of the two inlet valve covers is located above the inlet valve 208 at the port of the second end of the second cylinder 208 for preventing the inlet valve 208 at the port of the second end of the second cylinder 208 from moving all the way up under the impact of the produced fluid. Another inlet valve housing is located above the inlet valve 208 at the port of the second end of the second plunger 206 for preventing product fluid in the second barrel from impacting the inlet valve 208 at the port of the second end of the second plunger 206 as it enters the second plunger 206, the inlet valve 208 moving upwards under the impact of the product fluid. The liquid outlet valve cover is positioned at the upper part of the liquid outlet valve 209 at the liquid outlet at the first end of the piston and is used for preventing the liquid outlet valve 209 from being impacted by the produced liquid when the produced liquid in the piston 205 flows out of the piston 205, and the liquid outlet valve 209 moves upwards all the time under the impact of the produced liquid.

In addition, when the coal bed gas production system provided by the application is used, in order to enable the sealing effect between the dual-fluid nipple 203 and the second tubing string 202 to be better, the downhole system 20 can further comprise a first sealing nipple 210. The first seal sub 210 is positioned between a sidewall of the first end of the dual-pass fluid sub 203 and the second tubing string 202 to sealingly connect the sidewall of the first end of the dual-pass fluid sub 203 with the second tubing string 202.

In addition, when the coal bed gas production system provided by the present application is used, in order to make the sealing effect between the second pump barrel 207 and the second tubing string 202 better, the downhole system 20 may further include a second sealing nipple 211. A second seal sub 211 is located between a sidewall of the first end of the second barrel 207 and the second tubing string 202 to sealingly connect the sidewall of the first end of the second barrel 207 with the second tubing string 202.

In addition, when the coal bed methane gas production system provided by the present application is used, the power fluid can flow undisturbed when flowing into the first port of the power fluid channel 2031 through the power pump 101, the first accumulator 102, and the reversing mechanism 103, and the downhole system 20 can further include a hollow rod 212. The first end of the hollow rod 212 is connected to the second end of the reversing mechanism 103, and the port of the second end of the hollow rod 212 is communicated with the first port of the power fluid channel 2031. Generally, the hollow bar 212 may also be referred to as a speed bar.

It should be noted that, in the coal bed gas production system that this application provided, two-way liquid nipple 203 of passing can be cylindric structure, and it has first recess and first through-hole to open on two-way liquid nipple 203's the first end port, and communicates with the port of the first end of hydraulic cylinder in the first through-hole, and first through-hole can regard as producing liquid passageway 2032. A second groove is formed in the position, close to the second end of the double-passage liquid nipple, of the side wall of the double-passage liquid nipple 203, the second groove is communicated with the first groove, and the communicated first groove and the second groove are used as power liquid channels 2031.

The following specifically describes the installation process of the coal bed gas production system provided by the present application:

when the coal bed gas production system provided by the application needs to be used, the power pump 101 and the first accumulator 102 are both connected with the first end of the reversing mechanism 103. The second casing string 201 is then lowered into the coal seam gas. A second tubing string 202 with a first sealing sub 210 and a second sealing end sub 211 is run into the second casing string 201 with both the first sealing sub 210 and the second sealing sub 211 at predetermined positions. The dual-pass hydraulic sub 203, the hydraulic cylinder 204, the piston 205, the second plunger 206 and the second pump cylinder 207 are all lowered into the second tubing string 202 through the hollow rod 212, and the dual-pass hydraulic sub 203 is ensured to be in contact with the first sealing sub 210, so that the dual-pass hydraulic sub 203 is in sealing connection with the second tubing string 202. The second pump barrel 207 is in contact with a second sealing sub 211 to sealingly connect the second pump barrel 207 to the second tubing string 202. The hollow rod 212 is then connected to the diverter mechanism 103 and the fluid production outlet end of the tubing string is connected to the second accumulator 105 and the pressure limiting valve 106.

When the rodless pump gas production system provided by the application is used, power fluid is injected into the first port of the power fluid channel through the power pump, the first energy accumulator and the reversing mechanism, and then the power fluid flows out of the second port of the power fluid channel. The power liquid enters the hydraulic cylinder through the through hole on the side wall of the second end of the hydraulic cylinder. After the power fluid enters the hydraulic cylinder, the power fluid can drive the piston to move upwards. And the side wall of the first end of the double-liquid passing nipple is in sealing connection with the second oil pipe string, and the side wall of the first end of the second pump cylinder is in sealing connection with the second oil pipe string, so that the produced liquid at the bottom of the coal bed methane well can only flow into the second pump cylinder. When the power fluid drives the piston to move upwards, the piston drives the second plunger to move upwards, and produced liquid at the bottom of the coal bed methane well enters the second pump cylinder through the liquid inlet valve at the port position of the second end of the second pump cylinder and further enters the second plunger. The production fluid passes through the second plunger and into the piston. Because the port position of the first end of the piston is provided with the liquid outlet, the produced liquid can flow out of the piston and flow into the inner space of the second oil pipe string passing through the upper part of the liquid nipple through the liquid producing channel, and then the produced liquid is conveyed to the ground through the second oil pipe string. When the produced liquid in the coal bed gas well enters the second pump barrel, the coal bed gas in the coal bed gas well is conveyed to the ground through the space between the second oil pipe string and the second sleeve string.

That is, in this application, drive the piston through power fluid, when the piston upward movement, the piston drives the second plunger upward movement, and when the second plunger upward movement, the production liquid in coal bed gas shaft bottom enters into the second pump section of thick bamboo, and then enters into in second plunger and the piston, enters into the inner space of the second oil pipe cluster of bi-pass liquid nipple upper portion through producing the liquid passageway at last. Because the pumping rod is not arranged in the gas production system, and the piston is driven by the power fluid to enable the produced fluid at the bottom of the coal bed gas well to flow to the ground, the problem that the pumping rod and the second oil pipe string are mutually abraded in the related technology is solved. Moreover, because the sucker rod and the second oil pipe string are not mutually abraded in the application, the rodless pump mining system does not need to be stopped, so that the mining of the coal bed gas is not interrupted, and the efficiency of mining the coal bed gas can be improved.

Fig. 4 is a flowchart of a method for producing coal bed methane according to an embodiment of the present application. The method is applied to the coal bed gas production system provided by the embodiment of the application. As shown in fig. 4, the method includes:

step 401: and controlling the power pump to be in a working state.

In some embodiments, the power pump may be connected to a terminal, and when the coal bed gas production system provided by the embodiment of the present application needs to be used to produce coal bed gas, the terminal sends a start instruction to the power pump, and the power pump receives the start instruction and starts to work. When the power pump starts to work, the power pump can suck power liquid into the power pump.

Step 402: and controlling a first interface and a second interface of the reversing mechanism to be in a working state alternately so as to drive the piston to move up and down through the power liquid.

In some embodiments, the reversing mechanism may be connected to the terminal, and when the power station is in the working state, the terminal may send an opening instruction to the reversing mechanism, and the reversing mechanism receives the opening instruction and starts to work. When the reversing mechanism works, the first interface and the second interface of the reversing mechanism are alternately in a working state.

(1) The first channel of the reversing mechanism is opened, and the second channel is closed.

When the power pump and the reversing mechanism are both in working states, the power pump sucks power liquid. When the first channel of the reversing mechanism is opened and the second channel is closed, the power fluid in the power pump and the power fluid in the first accumulator continuously flow to the first interface of the reversing mechanism through the first channel. When the power fluid flows out of the reversing mechanism, the power fluid flows into the hollow rod, further flows into the first port of the power fluid channel and flows out of the second port of the power fluid channel. After the power fluid flows out from the second port of the power fluid channel, the power fluid flows into the hydraulic cylinder through the through hole in the side wall of the hydraulic cylinder so as to drive the piston to move upwards. When the piston moves upwards, the piston drives the second plunger to move upwards. After the second plunger moves upwards, the liquid inlet valve at the port of the second end of the second pump cylinder is opened, and the produced liquid at the bottom of the coal bed methane well enters the second pump cylinder.

After the produced fluid enters the second pump barrel, the fluid inlet valve at the port of the second end of the second plunger is opened, and the produced fluid enters the second plunger. Further, the product fluid enters the piston. After the produced liquid enters the piston, a liquid outlet valve at a produced liquid outlet at the first end of the piston is opened, and the produced liquid flows out of the piston and flows into the inner space of the second oil pipe string at the upper part of the two-way liquid passing short joint through the produced liquid channel. The production fluid continues to flow in the second tubing string and into the second accumulator. The second accumulator stores energy of the produced fluid. And when the pressure of the produced liquid is greater than the pressure threshold value of the pressure limiting valve, the produced liquid flows out of the pressure limiting valve and flows into the produced liquid pool. When the production liquid flows into the second pump barrel, the coal bed gas at the bottom of the coal bed gas well flows to the ground through the space between the second oil pipe string and the second sleeve string.

(2) The second channel of the reversing mechanism is opened, and the first channel is closed.

When the second channel of the reversing mechanism is opened and the first channel is closed, the power fluid which flows into the hydraulic cylinder is lack of power because the power fluid in the power pump and the power fluid in the second energy accumulator cannot flow into the hollow rod, and the piston cannot be driven to move upwards continuously. At this point, the second accumulator releases the energy of the production fluid, causing the piston to move downward. When the piston moves downwards, the power fluid in the hydraulic cylinder flows out of the hydraulic cylinder, flows into the hollow rod along the power fluid channel and further flows into the reversing mechanism. And the power fluid flowing into the reversing mechanism flows to a second interface of the reversing mechanism through a second channel and flows out of the second interface.

The upward movement of the piston may be referred to as an upstroke, and the downward movement of the piston may be referred to as a downstroke.

In addition, when the coal bed gas is mined by the coal bed gas mining system provided by the embodiment of the application, the coal bed gas well needs to be periodically cleaned, so that the coal bed gas mining method provided by the embodiment of the application can further comprise the following steps: when the coal-bed gas well needs to be cleaned, the first interface of the reversing mechanism is controlled to be kept in a communication state with the power pump, so that the reversing mechanism injects power liquid into the first port of the power liquid channel, the power liquid drives the piston to move upwards, the second piston is no longer located in the second pump cylinder, and the coal-bed gas well is cleaned through the power liquid.

Because coal powder is carried in the produced liquid at the bottom of the coal bed gas well, when the produced liquid passes through the liquid inlet valve at the second end of the second plunger and the liquid outlet valve at the liquid outlet at the first end of the piston, the coal powder can be accumulated at the liquid inlet valve and the liquid production valve to influence the liquid inlet valve and the liquid production valve. Therefore, the liquid inlet valve and the liquid production valve need to be cleaned. Cleaning the liquid production valve and the liquid inlet valve is also called cleaning the coal-bed gas well.

When the coal bed gas well needs to be cleaned, the terminal sends a control instruction to the reversing mechanism, and after the reversing mechanism receives the control instruction, the first interface of the reversing mechanism and the power pump are always kept in a communicated state. At the moment, the power pump continuously pumps power liquid into the reversing mechanism, and the power liquid enters the hollow rod through the first channel and then flows into the hydraulic cylinder along the power liquid channel and the through holes in the side wall of the hydraulic cylinder. After the power fluid enters the hydraulic cylinder, the piston is driven to move upwards, and the piston drives the second plunger to move upwards. Because the power pump can continuously pump power liquid into the hydraulic cylinder, the power liquid enables the piston to move upwards all the time. When the piston moves upward to the dead point, the piston does not move upward any more, and at this time, the second plunger is disengaged from the second cylinder, as shown in fig. 5. After disengagement of the second plunger from the second cylinder, the motive fluid can pass into the second plunger, and thus into the piston, along the inlet valve at the port of the second end of the second plunger. After the power liquid enters the piston, the power liquid flows out from a liquid outlet valve at a liquid outlet at the first end of the piston. After the power fluid flows out of the piston, the power fluid continues to flow through the fluid production channel and finally flows into the second accumulator or flows out through the pressure limiting valve.

When the power liquid passes through the liquid inlet valve at the port of the second end of the second plunger and the liquid outlet valve at the liquid outlet of the first end of the piston, the power liquid can continuously scour the liquid inlet valve and the liquid outlet valve, so that the coal powder at the liquid inlet valve and the coal powder at the liquid outlet valve can be scoured by the power liquid and flows out of the liquid production channel along with the power liquid.

In addition, when the coal bed gas mining system provided by the application is used for mining the coal bed gas, the daily gas production rate of the coal bed gas well can be monitored in real time. When the daily gas production of the coal-bed gas well is larger than the gas production threshold value, it is indicated that a power pump is not needed to pump power fluid into the hydraulic cylinder to drive the piston to move upwards, so that the produced fluid enters the second pump cylinder and further enters the second piston and the piston, and finally the produced fluid flows out from the produced fluid channel. At this time, the coal-bed gas well gas production method provided by the embodiment of the application can further include: when the daily gas production of the coal-bed gas well is greater than the daily gas production threshold, the double-passing liquid nipple is driven to move upwards, so that the space at the lower part of the sealing position of the second pump cylinder and the second oil pipe string is communicated with the space at the upper part of the sealing position of the second oil pipe string through the double-passing liquid nipple. The daily gas production threshold is also called a self-carrying liquid critical value.

And when the daily gas production of the coal-bed gas well is greater than the gas production threshold, indicating that the pressure of the coal bed in the bottom of the coal-bed gas well can drive the produced liquid at the bottom of the coal-bed gas well to flow to a coal-bed gas well mouth. At the moment, the piston is not required to be driven by the power fluid so that the production fluid at the bottom of the coal bed gas well flows from the bottom of the coal bed gas well to the top of the coal bed gas well. Thus, in some embodiments, the power pump and the reversing mechanism can be turned off and the dual-pass fluid sub can be driven upward to communicate the second pump barrel with the space below the second tubing string sealing location and the dual-pass fluid sub with the space above the second tubing string sealing location. At this time, the production liquid at the bottom of the coalbed methane well can flow along the space between the second pump cylinder and the second oil pipe string. And, production fluid can flow along the space between two passing liquid nipple and the oil rod cluster. Finally, the produced liquid flows to the coal bed gas wellhead, flows into the second accumulator or flows out through the pressure limiting valve. The process of driving the produced liquid from the bottom of the liquid-producing coalbed methane well to the top of the coalbed methane well by the pressure of the coal seam may also be referred to as flowing.

For example, as shown in fig. 6, the dual-pass hydraulic nipple is driven to move upward, the dual-pass hydraulic nipple drives the hydraulic cylinder to move upward, and the hydraulic cylinder drives the second pump barrel to move upward. So that the double-passing liquid nipple is not contacted with the first sealing nipple any more, and the second pump cylinder is not contacted with the second sealing nipple any more. At the moment, the space at the upper part of the sealing position of the double-pass liquid nipple and the second oil pipe string is communicated with the space at the lower part of the sealing position of the second pump cylinder and the second oil pipe string. The produced liquid at the bottom of the coal bed gas well can flow under the pressure of the coal bed, and firstly flows into the space at the lower part of the sealing position between the second pump cylinder and the second oil pipe string, then flows into the space at the upper part of the sealing position between the double-pass liquid nipple and the second oil pipe string, and finally flows to the coal bed gas well head.

And when the daily gas production of the coal bed gas well is smaller than the gas production threshold, indicating that the pressure of the coal bed in the bottom of the coal bed gas well is not enough to drive the produced liquid at the bottom of the coal bed gas well to flow to the coal bed gas wellhead. At the moment, the double-passage liquid nipple can be driven to move downwards, so that the space at the lower part of the sealing position of the second pump cylinder and the second oil pipe string is not communicated with the space at the upper part of the sealing position of the double-passage liquid nipple and the second oil pipe string. And the power pump and the reversing mechanism can be controlled to be in the working state again.

In this application embodiment, through power fluid drive piston, when the piston upward movement, the piston drives the second plunger upward movement, and when the second plunger upward movement, the production liquid in the coal bed methane shaft bottom enters into the second pump section of thick bamboo, and then enters into second plunger and piston, enters into the inner space of the second oil pipe cluster on two-way liquid nipple upper portion through producing the liquid passageway at last. Because the oil pumping rod is not arranged in the gas production system, and the power liquid drives the piston to further enable the produced liquid at the bottom of the coal bed methane well to flow to the ground, the problem that the oil pumping rod and the second oil pipe string are mutually abraded in the related technology is solved. Moreover, because the sucker rod and the second oil pipe string are not mutually abraded in the application, the rodless pump mining system does not need to be stopped, so that the mining of the coal bed gas is not interrupted, and the efficiency of mining the coal bed gas can be improved.

Fig. 7 is a schematic structural diagram of a coal bed methane gas production device according to an embodiment of the present application. As shown in fig. 7, the apparatus 700 includes:

the first control module 701 is used for controlling the power pump to be in a working state;

and the second control module 702 is configured to control the first interface and the second interface of the reversing mechanism to be alternately in a working state, so as to drive the piston to move up and down through the power fluid.

Optionally, the apparatus 700 further comprises:

and the third control module is used for controlling the first interface of the reversing mechanism to keep a communication state with the power pump when the coal-bed gas well needs to be cleaned, so that the reversing mechanism injects power liquid into the first port of the power liquid channel, the power liquid drives the piston to move upwards, the second piston is no longer positioned in the second pump cylinder, and the coal-bed gas well is cleaned through the power liquid.

Optionally, the apparatus 700 further comprises:

and the driving module is used for driving the double-passing liquid nipple to move upwards when the daily gas production of the coal-bed gas well is greater than a daily gas production threshold value, so that the space at the lower part of the sealing position of the second pump cylinder and the second oil pipe string is communicated with the space at the upper part of the sealing position of the second oil pipe string through the double-passing liquid nipple.

In this application embodiment, through power fluid drive piston, when the piston upward movement, the piston drives the second plunger upward movement, and when the second plunger upward movement, the liquid production in coal bed methane shaft bottom enters into the second pump section of thick bamboo, and then enters into in second plunger and the piston, enters into the inner space of the second oil pipe cluster on two pass through liquid nipple upper portions through producing the liquid passageway at last. Because the pumping rod is not arranged in the gas production system, and the piston is driven by the power fluid to enable the produced fluid at the bottom of the coal bed gas well to flow to the ground, the problem that the pumping rod and the second oil pipe string are mutually abraded in the related technology is solved. In addition, because the sucker rod and the second oil pipe string are not mutually abraded in the application, the rodless pump mining system does not need to be stopped, the coal bed gas is not mined continuously, and the coal bed gas mining efficiency can be improved.

The coal bed gas production device provided by the above embodiment is exemplified by only the division of the above functional modules when coal bed gas is produced, and in practical application, the above function distribution may be completed by different functional modules according to needs, that is, the internal structure of the device is divided into different functional modules to complete all or part of the above described functions. In addition, the coal bed gas production device provided by the embodiment and the coal bed gas production method embodiment belong to the same concept, and the specific implementation process is described in the method embodiment in detail and is not described herein again.

Fig. 8 shows a block diagram of a terminal 800 according to an exemplary embodiment of the present application. The terminal 800 may be: a smart phone, a tablet computer, an MP3 player (Moving Picture Experts Group Audio Layer III, motion video Experts compression standard Audio Layer 3), an MP4 player (Moving Picture Experts Group Audio Layer IV, motion video Experts compression standard Audio Layer 4), a notebook computer, or a desktop computer. The terminal 800 may also be referred to as a user equipment, portable terminal, laptop terminal, desktop terminal, or the like, among other names.

In general, the terminal 800 includes: a processor 801 and a memory 802.

Processor 801 may include one or more processing cores, such as a 4-core processor, an 8-core processor, and so forth. The processor 801 may be implemented in at least one hardware form of a DSP (Digital Signal Processing), an FPGA (Field-Programmable Gate Array), and a PLA (Programmable Logic Array). The processor 801 may also include a main processor and a coprocessor, where the main processor is a processor for Processing data in an awake state, and is also called a Central Processing Unit (CPU); a coprocessor is a low power processor for processing data in a standby state. In some embodiments, the processor 801 may be integrated with a GPU (Graphics Processing Unit), which is responsible for rendering and drawing the content required to be displayed on the display screen. In some embodiments, the processor 801 may further include an AI (Artificial Intelligence) processor for processing computing operations related to machine learning.

Memory 802 may include one or more computer-readable storage media, which may be non-transitory. Memory 802 can also include high-speed random access memory, as well as non-volatile memory, such as one or more magnetic disk storage devices, flash memory storage devices. In some embodiments, a non-transitory computer readable storage medium in the memory 802 is configured to store at least one instruction for execution by the processor 801 to implement the methods of coal bed gas production provided by the method embodiments of the present application.

In some embodiments, the terminal 800 may further include: a peripheral interface 803 and at least one peripheral. The processor 801, memory 802, and peripheral interface 803 may be connected by buses or signal lines. Various peripheral devices may be connected to peripheral interface 803 by a bus, signal line, or circuit board. Specifically, the peripheral device includes: at least one of a radio frequency circuit 804, a touch screen display 805, a camera assembly 806, an audio circuit 807, a positioning assembly 808, and a power supply 809.

The peripheral interface 803 may be used to connect at least one peripheral related to I/O (Input/Output) to the processor 801 and the memory 802. In some embodiments, the processor 801, memory 802, and peripheral interface 803 are integrated on the same chip or circuit board; in some other embodiments, any one or two of the processor 801, the memory 802, and the peripheral interface 803 may be implemented on separate chips or circuit boards, which is not limited by the present embodiment.

The Radio Frequency circuit 804 is used for receiving and transmitting RF (Radio Frequency) signals, also called electromagnetic signals. The radio frequency circuitry 804 communicates with communication networks and other communication devices via electromagnetic signals. The rf circuit 804 converts an electrical signal into an electromagnetic signal to be transmitted, or converts a received electromagnetic signal into an electrical signal. Optionally, the radio frequency circuit 804 includes: an antenna system, an RF transceiver, one or more amplifiers, a tuner, an oscillator, a digital signal processor, a codec chipset, a subscriber identity module card, and so forth. The radio frequency circuit 804 may communicate with other terminals via at least one wireless communication protocol. The wireless communication protocols include, but are not limited to: metropolitan area networks, various generation mobile communication networks (2G, 3G, 4G, and 5G), Wireless local area networks, and/or WiFi (Wireless Fidelity) networks. In some embodiments, the radio frequency circuit 804 may further include NFC (Near Field Communication) related circuits, which are not limited in this application.

The display screen 805 is used to display a UI (user interface). The UI may include graphics, text, icons, video, and any combination thereof. When the display 805 is a touch display, the display 805 also has the ability to capture touch signals on or above the surface of the display 805. The touch signal may be input to the processor 801 as a control signal for processing. At this point, the display 805 may also be used to provide virtual buttons and/or a virtual keyboard, also referred to as soft buttons and/or a soft keyboard. In some embodiments, the display 805 may be one, providing the front panel of the terminal 800; in other embodiments, the display 805 may be at least two, respectively disposed on different surfaces of the terminal 800 or in a folded design; in still other embodiments, the display 805 may be a flexible display disposed on a curved surface or a folded surface of the terminal 800. Even further, the display 805 may be arranged in a non-rectangular irregular pattern, i.e., a shaped screen. The Display 805 can be made of LCD (Liquid Crystal Display), OLED (Organic Light-Emitting Diode), and other materials.

The camera assembly 806 is used to capture images or video. Optionally, camera assembly 806 includes a front camera and a rear camera. Generally, a front camera is disposed at a front panel of the terminal, and a rear camera is disposed at a rear surface of the terminal. In some embodiments, the number of the rear cameras is at least two, and each rear camera is any one of a main camera, a depth-of-field camera, a wide-angle camera and a telephoto camera, so that the main camera and the depth-of-field camera are fused to realize a background blurring function, and the main camera and the wide-angle camera are fused to realize panoramic shooting and VR (Virtual Reality) shooting functions or other fusion shooting functions. In some embodiments, camera assembly 806 may also include a flash. The flash lamp can be a monochrome temperature flash lamp or a bicolor temperature flash lamp. The double-color-temperature flash lamp is a combination of a warm-light flash lamp and a cold-light flash lamp, and can be used for light compensation at different color temperatures.

The audio circuitry 807 may include a microphone and a speaker. The microphone is used for collecting sound waves of a user and the environment, converting the sound waves into electric signals, and inputting the electric signals to the processor 801 for processing or inputting the electric signals to the radio frequency circuit 804 to realize voice communication. The microphones may be provided in a plurality, respectively, at different portions of the terminal 800 for the purpose of stereo sound collection or noise reduction. The microphone may also be an array microphone or an omni-directional pick-up microphone. The speaker is used to convert electrical signals from the processor 801 or the radio frequency circuit 804 into sound waves. The loudspeaker can be a traditional film loudspeaker or a piezoelectric ceramic loudspeaker. When the speaker is a piezoelectric ceramic speaker, the speaker can be used for purposes such as converting an electric signal into a sound wave audible to a human being, or converting an electric signal into a sound wave inaudible to a human being to measure a distance. In some embodiments, the audio circuitry 807 may also include a headphone jack.

The positioning component 808 is used to locate the current geographic position of the terminal 800 for navigation or LBS (Location Based Service). The Positioning component 808 may be a Positioning component based on the GPS (Global Positioning System) in the united states, the beidou System in china, the graves System in russia, or the galileo System in the european union.

Power supply 809 is used to provide power to various components in terminal 800. The power source 809 may be ac, dc, disposable or rechargeable. When the power source 809 comprises a rechargeable battery, the rechargeable battery may support wired or wireless charging. The rechargeable battery may also be used to support fast charge technology.

In some embodiments, terminal 800 also includes one or more sensors 810. The one or more sensors 810 include, but are not limited to: acceleration sensor 811, gyro sensor 812, pressure sensor 813, fingerprint sensor 814, optical sensor 815 and proximity sensor 816.

The acceleration sensor 811 may detect the magnitude of acceleration in three coordinate axes of the coordinate system established with the terminal 800. For example, the acceleration sensor 811 may be used to detect components of the gravitational acceleration in three coordinate axes. The processor 801 may control the touch screen 805 to display the user interface in a landscape view or a portrait view according to the gravitational acceleration signal collected by the acceleration sensor 811. The acceleration sensor 811 may also be used for acquisition of motion data of a game or a user.

The gyro sensor 812 may detect a body direction and a rotation angle of the terminal 800, and the gyro sensor 812 may cooperate with the acceleration sensor 811 to acquire a 3D motion of the user with respect to the terminal 800. From the data collected by the gyro sensor 812, the processor 801 may implement the following functions: motion sensing (such as changing the UI according to a user's tilting operation), image stabilization at the time of photographing, game control, and inertial navigation.

Pressure sensors 813 may be disposed on the side bezel of terminal 800 and/or underneath touch display 805. When the pressure sensor 813 is disposed on the side frame of the terminal 800, the holding signal of the user to the terminal 800 can be detected, and the processor 801 performs left-right hand recognition or shortcut operation according to the holding signal collected by the pressure sensor 813. When the pressure sensor 813 is disposed at a lower layer of the touch display screen 805, the processor 801 controls the operability control on the UI interface according to the pressure operation of the user on the touch display screen 805. The operability control comprises at least one of a button control, a scroll bar control, an icon control and a menu control.

The fingerprint sensor 814 is used for collecting a fingerprint of the user, and the processor 801 identifies the identity of the user according to the fingerprint collected by the fingerprint sensor 814, or the fingerprint sensor 814 identifies the identity of the user according to the collected fingerprint. Upon identifying that the user's identity is a trusted identity, the processor 801 authorizes the user to perform relevant sensitive operations including unlocking a screen, viewing encrypted information, downloading software, paying for and changing settings, etc. Fingerprint sensor 814 may be disposed on the front, back, or side of terminal 800. When a physical button or a vendor Logo is provided on the terminal 800, the fingerprint sensor 814 may be integrated with the physical button or the vendor Logo.

The optical sensor 815 is used to collect the ambient light intensity. In one embodiment, the processor 801 may control the display brightness of the touch screen 805 based on the ambient light intensity collected by the optical sensor 815. Specifically, when the ambient light intensity is high, the display brightness of the touch display screen 805 is increased; when the ambient light intensity is low, the display brightness of the touch display 805 is turned down. In another embodiment, the processor 801 may also dynamically adjust the shooting parameters of the camera assembly 806 based on the ambient light intensity collected by the optical sensor 815.

A proximity sensor 816, also known as a distance sensor, is typically provided on the front panel of the terminal 800. The proximity sensor 816 is used to collect the distance between the user and the front surface of the terminal 800. In one embodiment, when the proximity sensor 816 detects that the distance between the user and the front surface of the terminal 800 gradually decreases, the processor 801 controls the touch display 805 to switch from the bright screen state to the dark screen state; when the proximity sensor 816 detects that the distance between the user and the front surface of the terminal 800 becomes gradually larger, the processor 801 controls the touch display 805 to switch from the screen-on state to the screen-on state.

Those skilled in the art will appreciate that the configuration shown in fig. 8 is not intended to be limiting of terminal 800 and may include more or fewer components than those shown, or some components may be combined, or a different arrangement of components may be used.

The embodiment of the application also provides a non-transitory computer readable storage medium, and when the instructions in the storage medium are executed by a processor of the terminal, the terminal is enabled to execute the coal bed methane gas production method provided by the embodiment shown in fig. 4.

The embodiment of the present application also provides a computer program product containing instructions, which when run on a computer, causes the computer to execute the coalbed methane gas production method provided by the embodiment shown in fig. 4.

In summary, the present application is only a preferred embodiment and is not intended to be limited by the scope of the present application, and any modifications, equivalents, improvements, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A coal bed gas production system, characterized in that the coal bed gas production system comprises a surface system (10) and a downhole system (20);

the ground system (10) comprises a power pump (101), a first energy accumulator (102) and a reversing mechanism (103), wherein the power pump (101) and the first energy accumulator (102) are connected with a first end of the reversing mechanism (103);

the downhole system (20) comprises a second casing string (201), a second tubing string (202), a double-pass hydraulic sub (203), a hydraulic cylinder (204), a piston (205), a second plunger (206), and a second pump cylinder (207), wherein the second tubing string (202) is nested in the second casing string (201), and the double-pass hydraulic sub (203), the hydraulic cylinder (204), the piston (205), the second plunger (206), and the second pump cylinder (207) are all located in the second tubing string (202);

the dual-pass liquid nipple (203) comprises a power liquid channel (2031) and a liquid production channel (2032), a first port of the power liquid channel (2031) and a first port of the liquid production channel (2032) are both positioned at a first end port of the dual-pass liquid nipple (203), a second port of the power liquid channel (2031) is positioned on a side wall of the dual-pass liquid nipple (203), a second port of the liquid production channel (2032) is positioned at a second end port of the dual-pass liquid nipple (203), and the side wall of the first end of the dual-pass liquid nipple (203) is in sealing connection with the second oil pipe string (202);

a port of a second end of the reversing mechanism (103) is communicated with a first port of the power fluid channel (2031), a second port of the liquid production channel (2032) is communicated with a port of a first end of the hydraulic cylinder (204), a port of a second end of the hydraulic cylinder (204) is communicated with a port of a first end of the second pump barrel (207), a through hole is formed in the side wall of the second end of the hydraulic cylinder (204), and the side wall of the first end of the second pump barrel (207) is in sealing connection with the second oil pipe string (202);

the second plunger (206) and the piston (205) are both hollow structures, the piston (205) is positioned in the hydraulic cylinder (204), the outer wall of the piston (205) is in contact with the inner wall of the hydraulic cylinder (204), a liquid outlet is arranged at a port position of a first end of the piston (205), a port of a second end of the piston (205) is communicated with a port of a first end of the second plunger (206), a second end of the second plunger (206) is positioned in the second pump cylinder (207), and a liquid inlet valve (208) is arranged at a port position of the second end of the second plunger (206) and a port position of a second end of the second pump cylinder (207);

the ground system (10) further comprises a power liquid pool (104), a second energy accumulator (105), a pressure limiting valve (106) and a liquid producing pool (107);

the power liquid pool (104) is connected with a first end of the power pump (101), and a second end of the power pump (101) is connected with a first interface of the reversing mechanism (103), so that the power pump (101) can pump the power liquid in the power liquid pool (104) and convey the power liquid to the double-passage liquid nipple (203) through the first interface;

the power liquid pool (104) is also connected with a second interface of the reversing mechanism (103) so that the reversing mechanism (103) can convey the power liquid returned by the double-pass liquid nipple (203) to the power liquid pool (104);

the first end of the pressure limiting valve (106) and the second accumulator (105) are both connected with the liquid production outlet end of the second tubing string (202), and the second end of the pressure limiting valve (106) is connected with the liquid production pool (107).

2. The system of claim 1, wherein the downhole system (20) further comprises a drain valve (209), the drain valve (209) being located at a drain location at the first end of the piston (205).

3. The coal bed methane gas production system of claim 1, wherein the downhole system (20) further comprises a first seal sub (210);

the first sealing short joint (210) is positioned between the side wall of the first end of the double-passing liquid short joint (203) and the second oil pipe string (202) so as to enable the side wall of the first end of the double-passing liquid short joint (203) to be in sealing connection with the second oil pipe string (202).

4. The coal bed methane gas production system according to any one of claims 1 to 3, wherein the downhole system (20) further comprises a second seal sub (211);

the second sealing short joint (211) is positioned between the side wall of the first end of the second pump cylinder (207) and the second oil pipe string (202) so as to enable the side wall of the first end of the second pump cylinder (207) to be in sealing connection with the second oil pipe string (202).

5. The coal bed gas production system of any one of claims 1 to 3, wherein the downhole system further comprises a hollow rod (212);

the first end of the hollow rod (212) is connected with the second end of the reversing mechanism (103), and the port of the second end of the hollow rod (212) is communicated with the first port of the power fluid channel.

6. A coal bed gas production method applied to the coal bed gas production system of any one of claims 1 to 5, wherein the method comprises the following steps:

controlling the power pump to be in a working state;

7. The method of mining coal bed methane according to claim 6, further comprising:

when the coal-bed gas well needs to be cleaned, the first interface of the reversing mechanism is controlled to be kept in a communication state with the power pump, so that the reversing mechanism injects power fluid into the first port of the power fluid channel, the power fluid drives the piston to move upwards, the second piston is no longer located in the second pump cylinder, and the coal-bed gas well is cleaned through the power fluid.

8. The method of mining coal bed methane according to claim 6, further comprising:

and when the daily gas production of the coal-bed gas well is greater than the daily gas production threshold value, driving the double liquid passing nipple to move upwards so as to communicate the space at the lower part of the sealing position of the second pump cylinder and the second oil pipe string and the space at the upper part of the sealing position of the double liquid passing nipple and the second oil pipe string.

9. A coal bed gas production apparatus for implementing the coal bed gas production method according to any one of claims 6 to 8, the apparatus comprising:

and the second control module is used for controlling the first interface and the second interface of the reversing mechanism to be in a working state alternately so as to drive the piston to move up and down through the power liquid.

10. The coal bed methane gas production apparatus of claim 9, further comprising:

11. The coal bed methane gas production apparatus of claim 9, further comprising:

12. A coal bed gas production device, characterized in that the device includes:

a processor;

a memory for storing processor-executable instructions;

wherein the processor is configured to perform the steps of the coal bed methane gas production method of any one of claims 6 to 8.

13. A computer readable storage medium having stored thereon instructions which, when executed by a processor, carry out the steps of the method of coal bed gas production of any one of claims 6 to 8.