A drainage gas recovery lifting system for a coal bed methane well

Abstract

The application provides a drainage gas recovery lifting system for a coal seam gas well, which comprises a drum type machine drainage recovery device and a machine drainage gas recovery lifting system; the output end of the drum type machine drainage recovery device is connected with the load bearing rope of the machine drainage gas recovery lifting system; the machine drainage gas recovery lifting system comprises a first oil pipe structure, a pumping beam structure and a directional flow channel plunger type gas and water separation recovery system, the first oil pipe structure is arranged in the wellbore of the gas well, the pumping beam structure is arranged in the first oil pipe structure, the bottom of the pumping beam structure is connected with the continuous oil rod of the directional flow channel plunger type gas and water separation recovery system, and the top of the directional flow channel plunger type gas and water separation recovery system is detachably connected with the first oil pipe structure. The drainage gas recovery lifting system for the coal seam gas well solves the problem that the rod pump machine drainage system in the related art cannot meet the sharp change of the formation liquid production, thereby causing the problem that the drainage recovery system cannot be timely adjusted.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of natural gas development, and particularly relates to a drainage gas recovery lifting system for a coalbed gas well. BACKGROUND

[0002] Coalbed gas (gas) refers to hydrocarbon gas stored in a coal seam, mainly composed of methane, mainly adsorbed on the surface of coal matrix particles, partially free in the coal void or dissolved in the coal seam water, is a byproduct of coal and belongs to unconventional natural gas. One of the coalbed gas mining methods is ground in-situ mining, that is, drainage mining is carried out through ground drainage gas recovery wells, and the drainage mining of the coalbed gas well is a continuous drainage gas recovery and pressure reduction process.

[0003] At present, the domestic coalbed gas drainage equipment basically follows the oilfield rod pump oil recovery technology, and the establishment of the coalbed gas drainage work system and the selection of the drainage equipment are mainly based on the past experience, and a perfect and mature drainage technology system for different geological characteristics has not been formed. Therefore, the rod pump drainage technology of the coalbed gas well accounts for more than 98%, but there are many problems.

[0004] Because the rod pump pumping system in the related art cannot meet the sharp change of the formation liquid output, the problem that the drainage system cannot be adjusted in time is caused, and the slow, long-term, continuous and stable drainage requirements of the coalbed gas well in different production stages cannot be met; while meeting the timely adjustment of the drainage system, the problems of realizing automatic control of the drainage intensity and controlling the operation according to the two types of drainage management system requirements of constant pressure or constant production are solved; the traditional pumping single well occupies a large area; the transmission link is more, the stroke is short, the number of strokes is fast, the system efficiency is low, the energy consumption is high, and the rod and pipe are seriously worn, which shortens the service life of the rod and pipe. The rod pump type technology is relatively mature, but is easily affected by sand and gas, the pump is seriously worn, the pump efficiency is reduced, the output of solid particles will cause the pump to be stuck, and the operation cost is increased. SUMMARY

[0005] Therefore, the present application aims to at least solve one of the problems in the related art to some extent.

[0006] To achieve the above-mentioned purpose, the technical scheme of the present application is as follows:

[0007] A drainage gas recovery lifting system for a coalbed gas well, comprising a drum type pumping drainage device and a pumping drainage gas recovery lifting system;

[0008] The output end of the drum type pumping drainage device is connected with the load rope of the pumping drainage gas recovery lifting system.

[0009] The machine pumping water drainage gas lifting system comprises a first oil pipe structure, a pumping oil slick rod structure and a directional flow channel plunger type gas and water separation system, the first oil pipe structure is arranged in a gas well shaft, the pumping oil slick rod structure is arranged in the first oil pipe structure, the bottom of the pumping oil slick rod structure is connected with a continuous oil rod of the directional flow channel plunger type gas and water separation system, and the top of the directional flow channel plunger type gas and water separation system is detachably connected with the first oil pipe structure.

[0010] The pumping oil slick rod structure comprises a bearing rope, a sealing sleeve, a flow guide short circuit, a positioning short circuit and a dynamic sealing structure, one end of the bearing rope is connected with an output end of a drum type machine pumping drainage device, the other end of the bearing rope is connected with the dynamic sealing structure, the dynamic sealing structure is slidably arranged on the inside of the sealing sleeve, the dynamic sealing structure is connected with the continuous oil rod, the bottom of the sealing sleeve is provided with the flow guide short circuit and the positioning short circuit, and the positioning short circuit is detachably connected with the bottom of the first oil pipe structure.

[0011] Further, the dynamic sealing structure comprises a first sealing plunger and a second sealing plunger, the top of the first sealing plunger is connected with the bearing rope through a cable joint, the bottom of the first sealing plunger is provided with the second sealing plunger, and the second sealing plunger is connected with the continuous oil rod.

[0012] Further, the directional flow channel plunger type gas and water separation system comprises a second oil pipe structure, a continuous oil rod, a connecting structure, a pumping rod, a pump pull rod, a conical pump cylinder, a double-closed structure plunger, a disc type liquid and gas separator and a self-cleaning guide fixed valve, the top of the second oil pipe structure is detachably connected with the bottom of the first oil pipe structure, the bottom of the second oil pipe structure is connected with the conical pump cylinder, the bottom of the conical pump cylinder is provided with the disc type liquid and gas separator, the top of the continuous oil rod is connected with the second sealing plunger, the bottom of the continuous oil rod is connected with the pumping rod through the connecting structure, the bottom of the pumping rod is connected with the double-closed structure plunger through the pump pull rod, the disc type liquid and gas separator and the self-cleaning guide fixed valve are both located below the double-closed structure plunger, the self-cleaning guide fixed valve is arranged between the disc type liquid and gas separator and the double-closed structure plunger, and the double-closed structure plunger and the self-cleaning guide fixed valve are both arranged in the conical pump cylinder.

[0013] Further, the inclination angle of the side wall of the conical pump cylinder is 5°-10°.

[0014] Further, the drum type machine pumping device comprises a truss support, a well mouth guide pulley, an adjusting pull rod, a foundation base, a drum structure, a motor, a speed reducer, a rope discharging mechanism and a moving base, the well mouth guide pulley is arranged at the top of the truss support, the bottom of the truss support is hinged to the foundation base, one end of the adjusting pull rod is hinged to the top of the truss support, the bottom of the adjusting pull rod is hinged to the foundation base, the moving base is connected to the foundation base through a sliding structure, the drum structure, the motor and the speed reducer are arranged on the moving base, the output end of the motor is connected to the input shaft of the speed reducer, the output shaft of the speed reducer is a hollow shaft, one end of the output shaft of the speed reducer is connected to the drum structure, the other end of the output shaft of the speed reducer is threadedly connected to the threaded end of the rope discharging mechanism, the fixed end of the rope discharging mechanism is arranged on the foundation base, the load bearing rope is wound on the drum structure, and the well mouth guide pulley is used for guiding the load bearing rope.

[0015] Further, the drum type machine pumping device further comprises a safety operation platform, and the safety operation platform is arranged on the truss support.

[0016] Further, the sliding structure comprises two guide sliding rails arranged side by side, and the moving base is slidably connected to the two guide sliding rails through moving rollers arranged on the side of the moving base.

[0017] Further, the guide sliding rail is provided with an origin switch, and an upper limit switch and a lower limit switch are arranged at the front end and the rear end of the guide sliding rail respectively.

[0018] Further, the drum structure comprises a Ribas drum and two drum supports, the Ribas drum is connected to the upper end surface of the moving base through the two drum supports, and the Ribas drum is used for winding the load bearing rope.

[0019] Further, the device further comprises a jet flow backflow device, the jet flow backflow device comprises a suction inlet, a power source interface and a diffusion pipe, the suction inlet is arranged at the inlet end of the diffusion pipe, the power source interface is arranged at the inlet end of the diffusion pipe, the outlet end of the diffusion pipe is connected to a gas pipeline through a pipeline, and the suction inlet is connected to the overflow outlet of a Christmas tree four-way joint.

[0020] Compared with the prior art, the drainage gas recovery lifting system for a coal bed gas well has the following advantages:

[0021] 1. The drainage and production device of the drum machine and the corresponding drainage rod structure and directional flow channel plunger type gas and water separation system are composed; due to the increase of the inclination angle, the depth of the drainage pump is affected, especially the super long stroke drainage pump, which meets the requirements of the coal bed methane well drainage and gas production on the depth of the pump hanging.

[0022] 2. The principle of the disc type gas anchor gas separation is to use the gas collection disc as the bubble trap, to collect the bubbles, and to use the centrifugal effect of the 90° turning of the liquid flow to separate the liquid and gas. When the gas is collected and overflowed in the disc, large bubbles are formed, which float along the inner wall of the gas anchor shell to the gas cap, and then enter the oil jacket annular space through the exhaust hole, while the liquid enters the pump through the suction hole. BRIEF DESCRIPTION OF DRAWINGS

[0023] The drawings that form a part of the present application are used to provide a further understanding of the present application, the illustrative embodiments of the present application and the description thereof are used to explain the present application, and do not constitute an improper limitation on the present application. In the drawings:

[0024] Figure 1 A drainage and gas production lifting system for a coal bed methane well according to an embodiment of the present application;

[0025] Figure 2 A structure diagram of the drainage and production device of the drum machine according to an embodiment of the present application;

[0026] Figure 3 A structure diagram of the drainage and production device of the drum machine according to an embodiment of the present application.

[0027] BRIEF DESCRIPTION OF DRAWINGS

[0028] 1, well head guide pulley; 2, pulley bearing support; 3, top platform; 4, truss body; 5, safety operation platform; 6, pin shaft; 7, adjusting pull rod; 8, base pedestal; 9, lower limit sliding rail; 10, upper limit sliding rail; 11, moving base; 12, moving roller; 13, horizontal reversing wheel; 14, ribas roller; 15, roller support; 16, first coupling; 17, speed reducer; 18, rope arranging mechanism; 19, motor; 20, second coupling; 21, manual-electric integrated brake; 22, load bearing rope; 23, cable joint; 24, first sealing plunger; 25, second sealing plunger; 26, suspension sealer; 27, Christmas tree cross; 28, sealing sleeve; 29, flow guiding short connection; 30, positioning short connection; 31, blowout prevention manual gate valve; 32, telescopic blowout prevention pipe; 33, jet flow backflow device; 34, tubing hanger; 35, tubing head large cross; 36, first tubing structure; 37, conical pump cylinder; 38, self-cleaning guide fixed valve; 39, disc type liquid-gas separator; 40, siphon tail pipe; 41, continuous oil rod; 42, safety joint; 43, positive and negative connection head; 44, sucker rod; 45, pump pull rod; 46, double closed structure plunger. DETAILED DESCRIPTION

[0029] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0030] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, the terms "first", "second" and the like are only for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined with "first", "second" and the like can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise stated, the meaning of "a plurality of" is two or more.

[0031] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connection", "linking" should be understood in a broad sense, for example, it can be fixed connection, or detachable connection, or integral connection; it can be mechanical connection, or electrical connection; it can be direct connection, or indirect connection through intermediate medium, or internal connection of two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0032] The present application will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

[0033] A drainage gas recovery lifting system for coal bed methane well, as shown in Figure 1 、 Figure 2 and Figure 3 , comprising a drum-type machine drainage recovery device and a machine drainage gas recovery lifting system; the output end of the drum-type machine drainage recovery device is connected with the load rope 22 of the machine drainage gas recovery lifting system; the machine drainage gas recovery lifting system comprises a first oil pipe structure 36, a pumping rod structure and a directional flow channel plunger type gas-water separation system, the first oil pipe structure 36 is arranged in the wellbore of the gas well, the pumping rod structure is arranged in the first oil pipe structure 36, the bottom of the pumping rod structure is connected with the continuous oil rod 41 of the directional flow channel plunger type gas-water separation system, and the top of the directional flow channel plunger type gas-water separation system is detachably connected with the first oil pipe structure 36.

[0034] The pumping rod structure comprises the load rope 22, a sealing sleeve 28, a flow guide short circuit 29, a positioning short circuit 30 and a dynamic sealing structure, one end of the load rope 22 is connected with the output end of the drum-type machine drainage recovery device, the other end of the load rope 22 is connected with the dynamic sealing structure, the dynamic sealing structure is slidably arranged inside the sealing sleeve 28, the dynamic sealing structure is connected with the continuous oil rod 41, the flow guide short circuit 29 and the positioning short circuit 30 are arranged at the bottom of the sealing sleeve 28, and the positioning short circuit 30 is detachably connected with the bottom of the first oil pipe structure 36.

[0035] The dynamic sealing structure comprises a first sealing plunger 24 and a second sealing plunger 25, the top of the first sealing plunger 24 is connected with the load rope 22 through a cable joint 23, the bottom of the first sealing plunger 24 is provided with the second sealing plunger 25, and the second sealing plunger 25 is connected with the continuous oil rod 41.

[0036] The directional flow channel plunger type gas-water separation system comprises a second oil pipe structure, a continuous oil rod 41, a connecting structure, a sucker rod 44, a pump pull rod 45, a conical pump cylinder 37, a double closed structure plunger 46, a disc type liquid-gas separator 39 and a self-cleaning guide fixed valve 38. The top of the second oil pipe structure is detachably connected with the bottom of the first oil pipe structure 36. The bottom of the second oil pipe structure is connected with the conical pump cylinder 37. The bottom of the conical pump cylinder 37 is provided with the disc type liquid-gas separator 39. The top of the continuous oil rod 41 is connected with the second sealing plunger 25. The bottom of the continuous oil rod 41 is connected with the sucker rod 44 through the connecting structure. The bottom of the sucker rod 44 is connected with the double closed structure plunger 46 through the pump pull rod 45. The disc type liquid-gas separator 39 and the self-cleaning guide fixed valve 38 are both located below the double closed structure plunger 46. The self-cleaning guide fixed valve 38 is arranged between the disc type liquid-gas separator 39 and the double closed structure plunger 46. The double closed structure plunger 46 and the self-cleaning guide fixed valve 38 are both arranged in the conical pump cylinder 37. The inclination angle of the side wall of the conical pump cylinder 37 is 5°-10°.

[0037] The conical pump cylinder 37 is composed of a conical section and an equal diameter section. The conical section is located at the upper part of the equal diameter section of the pump cylinder. Since the stroke length is more than 15 m, the plunger runs in the equal diameter pump cylinder part most of the time in the upstroke. Once the conical section of the pump cylinder is exposed from the bottom of the double closed structure plunger 46, the gap between the double closed structure plunger 46 and the inner wall of the pump cylinder will suddenly increase and continuously increase with the continuous upward movement of the double closed structure plunger 46. Therefore, from the beginning of the exposure of the conical section of the pump cylinder from the bottom of the plunger, the gas accumulated in the pump cylinder is gradually replaced by the well fluid in the high pressure area of the upper part of the movable valve. The replacement process may continue until the plunger reaches the top dead center. The pumping unit can stay at the top dead center position for a certain period of time according to the actual situation to make the gas-liquid replacement more sufficient. The replacement process may also end early, which depends on the amount of gas accumulated in the pump cylinder. At the same time, with the mutual replacement process of the gas in the pump cylinder and the well fluid in the high pressure area of the upper part of the movable valve, the pressure difference between the upper and lower parts of the movable valve will gradually decrease, so that the upper and lower parts of the movable valve are in a balanced state. Therefore, the movable valve will be opened in time in the downstroke to avoid the opening lag phenomenon of the movable valve. The plunger adopts a double closed structure between the upper opening valve cover and the plunger, and a closed valve cover is added. The valve ball is installed in the closed valve cover. The valve ball can avoid hitting the opening valve cover when the valve ball is opened in the upstroke, effectively reducing the risk of breaking of the upper valve cover. The fixed valve assembly adopts a spring guide structure to ensure that the fixed valve ball of the oil well pump opens and closes freely and the valve seat remains sealed when the inclination angle of the well is ≤65°. There is a downward inclined hole on the self-cleaning cover of the fixed valve. When the flowing well fluid passes through the inclined hole in the upstroke, it will flush the bottom annulus of the pump downward to realize the self-cleaning function, so that the coal powder is not easy to deposit in the annulus, the pump efficiency is improved, and the problem of coal powder blocking the fixed valve and not discharging liquid is prevented.

[0038] The disc-type liquid-gas separator 39 uses a gas collecting disc to capture bubbles. After the bubbles are gathered, the centrifugal effect of the liquid flow turning at 90° is used to separate the liquid and gas. When the gas accumulates and overflows in the disc, it forms a large bubble, which floats up along the inner wall of the gas anchor shell to the gas cap, and then through the exhaust hole to the annular space of the oil casing. The liquid enters the suction pipe from the suction hole and enters the pump barrel of the oil pump. The small-diameter tailpipe connected to the bottom of the liquid disc-type gas anchor is used to solve the problem of the increased well inclination angle affecting the lowering depth of the oil pump. It maximizes the satisfaction of the pump lowering depth requirements for drainage and gas production in coalbed methane wells. The tailpipe is added to lower the pump inlet using the siphon principle, thereby achieving the purpose of deepening the pump.

[0039] The gas wellhead is equipped with a tubing head crossover 35 and a tree trunk crossover 27. The upper flange at the top of the tubing head crossover 35 is fixedly connected to the lower flange at the bottom of the tree trunk crossover 27. A tubing hanger 34 is installed inside the upper flange of the tubing head crossover 35, and the lower end of the tubing hanger 34 is connected to the first tubing structure 36 and the second tubing structure. An overflow outlet is opened on the side of the upper flange of the tree trunk crossover 27. The overflow outlet is connected to the suction pipe of the jet return device 33 at the wellhead. The air inlet pipe of the jet return device 33 is connected to the outlet end of the casing gate valve of the tubing head crossover 35. The diffuser is connected to the gas production pipeline. A blowout preventer (BOP) is also connected to the upper flange of the tree trunk crossover 27, and a retractable BOP 32 is installed on the upper part of the BOP.

[0040] The downhole sealing sleeve is suspended in the upper flange of the production tree cross 27 by the suspension seal 26, and is concentrically sealed with the tubing hanger 34. It is inserted into the tubing at the upper end of the downhole production string. The annular space formed by the outer wall of the sealing sleeve 28 and the inner wall of the downhole tubing is the channel for the drainage of the tubing from the mechanical pumping drainage gas production lift system to the surface. This annular channel is connected to the production fluid channel on the side of the tubing cross.

[0041] The annular space formed by the outer wall of the downhole production tubing and the inner wall of the casing in the coalbed methane well serves as the gas production channel for the mechanical pumping, drainage, gas production, and lifting system. This annular space is connected to the casing gate on the side of the casing cross passage.

[0042] The annular space formed by the guide short-circuit 29 at the bottom of the sealing working cylinder and the outer wall of the sealing sleeve 28 and the inner wall of the downhole tubing is connected. The first sealing plunger 24 and the second sealing plunger 25 of the wire rope sucker rod move up and down reciprocally under the drive of the drum of the machine pumping and production device inside the sealing working cylinder.

[0043] The lower end of the second sealing plunger 25 is connected to the downhole carbon fiber continuous sucker rod hybrid rod string, and the bottom end of the sucker rod 44 is connected to the long stroke sucker pump plunger, which is located inside the sucker pump barrel.

[0044] The downhole carbon fiber continuous sucker rod mixed rod string comprises a carbon fiber continuous sucker rod 41 and a sucker rod 44, the bottom end of the carbon fiber continuous sucker rod 41 is connected to the sucker rod 44 through a connecting structure (a safety joint 42 and a positive and negative connecting head 43), the sucker rod 44 is connected to a sucker pump plunger, the sucker pump plunger is provided with a double valve ball, a valve seat and a closed valve cover, and the sucker pump plunger is inserted into a downhole sucker pump cylinder through the sucker rod 44.

[0045] The conical pump cylinder 37 is composed of a conical section and an equal-diameter section, and the conical section is located at the upper part of the equal-diameter section. The conical anti-gas pump cylinder equal-diameter section is connected coaxially by several sections of pump cylinders plated with Cr or nitrocarburized, and the bottom end of the pump cylinder is provided with a slant hole loss prevention fixed valve ball assembly. The fixed valve assembly adopts a spring guide structure, the spring is made of Monel material, has good corrosion resistance, and the fixed valve has a downward inclined hole on the self-cleaning cover. The bottom end thread of the fixed valve assembly is connected to a disc-type gas anchor and a small-diameter tail pipe in sequence.

[0046] As shown in Figures 2-3 The drum-type machine pumping and extraction device comprises a truss support body 4, a wellhead guide pulley 1, an adjusting pull rod 7, a foundation base 8, a drum structure, a motor 19, a speed reducer 17, a rope discharging mechanism 18 and a movable base 11. The wellhead guide pulley 1 is arranged at the top of the truss support body 4, the bottom of the truss support body 4 is hingedly connected to the foundation base 8, one end of the adjusting pull rod 7 is hingedly connected to the top of the truss support body 4, and the bottom of the adjusting pull rod 7 is hingedly connected to the foundation base 8. The movable base 11 is connected to the foundation base 8 through a sliding structure. The drum structure, the motor 19 and the speed reducer 17 are arranged on the movable base 11. The output end of the motor 19 is connected to the input shaft of the speed reducer 17. The output shaft of the speed reducer 17 is a hollow shaft. One end of the output shaft of the speed reducer 17 is connected to the drum structure, and the other end of the output shaft of the speed reducer 17 is threadedly connected to the threaded end of the rope discharging mechanism 18. The fixed end of the rope discharging mechanism 18 is arranged on the foundation base 8. The load-bearing rope 22 is wound on the drum structure, and the wellhead guide pulley 1 is used for guiding the load-bearing rope 22. The drum-type machine pumping and extraction device further comprises a safety operation platform 5 arranged on the truss support body 4. The drum structure comprises a Libas drum 14 and two drum supports 15. The Libas drum 14 is connected to the upper end surface of the movable base 11 through the two drum supports 15. The Libas drum 14 is used for winding the load-bearing rope 22.

[0047] The sliding structure comprises two upper limit position sliding rails 10 and a lower limit position sliding rail 9. The upper limit position sliding rails 10 and the lower limit position sliding rail 9 are symmetrically arranged. The movable base 11 is slidably connected to the upper limit position sliding rails and the lower limit position sliding rail 9 through movable rollers 12 arranged on the side of the movable base 11. The movable base 11 is provided with radial limit position rollers.

[0048] The jet flow backflow device 33 includes a suction inlet, a power gas source interface and a diffusion pipe. The suction inlet is arranged at an inlet end of the diffusion pipe. The power gas source interface is arranged at an inlet end of the diffusion pipe. An outlet end of the diffusion pipe is connected with the gas production pipeline through a pipeline. The suction inlet is connected with the overflow outlet of the Christmas tree four-way valve 27.

[0049] The tubing hanger 34 is suspended in the upper flange of the tubing head large four-way valve 35. The tubing hanger 34 is connected with the first tubing structure 36, the conical pump cylinder 37 and the self-cleaning guide fixed valve 38 at the lower end of the conical pump cylinder 37 in sequence through threads. The fixed valve is connected with the disc type liquid gas separator 39 and the siphon tail pipe 40 in sequence. The oil jacket annular space formed by the outer wall of the first tubing structure 36 and the inner wall of the casing of the coalbed methane well is communicated with the large four-way valve gate of the tubing head large four-way valve 35 to form a gas production channel of the coalbed methane well. The load rope 22 is a steel wire rope.

[0050] The lower flange of the Christmas tree four-way valve 27 and the upper flange of the tubing head large four-way valve 35 are fixedly connected through bolts and nuts. The suspension seal device 26 is connected with the sealing working cylinder, the flow guide short connection 29 and the positioning short connection 30 in sequence through threads. The suspension seal device 26 is suspended in the upper flange of the Christmas tree four-way valve 27 through the sealing working cylinder. The annular space formed by the outer wall of the sealing sleeve 28 and the inner wall of the first tubing structure 36 is communicated with the small four-way valve gate of the Christmas tree four-way valve 27 to form a produced water channel of the coalbed methane well. The lower flange of the blowout manual gate valve 31 is fixedly connected with the upper flange of the Christmas tree four-way valve 27 through bolts. The lower flange of the telescopic blowout pipe 32 is fixedly connected with the upper flange of the blowout manual gate valve 31 through bolts. The suction inlet, the power gas source inlet and the outlet of the diffusion pipe of the jet flow backflow device 33 are respectively connected with the backflow outlet of the upper flange of the Christmas tree four-way valve 27 and the ground gas production pipeline of the tubing head large four-way valve 35. The cable joint 23 of the load rope 22 is connected with the first sealing plunger 24 and the second sealing plunger 25 in sequence. Then one end of the load rope 22 is wound and fixed on the roller.

[0051] The process rod string part in the directional flow channel plunger type gas and water separation and production system is implemented after the above implementation. The carbon fiber continuous oil rod 41 is connected with the safety joint 42, the positive and negative connection head 43, the sucker rod 44, the pump pull rod 45 and the double closed structure plunger 46 in sequence through threads. The process rod string passes through the blowout manual gate valve 31, the telescopic blowout pipe 32, the sealing working cylinder suspension seal device 26, the Christmas tree four-way valve 27, the sealing working cylinder, the flow guide short connection 29 and the positioning short connection 30 in the steel wire rope oil pumping polished rod and sealing system 2. The double closed structure plunger 46 is arranged in the conical pump cylinder 37. The whole process rod string is suspended on the telescopic blowout pipe 32 through special tools after the implementation.

[0052] Finally, the roller type machine pumping and drainage device in the machine pumping and drainage gas lifting system is implemented.

[0053] Wherein the base 8 is installed in the distance from the coalbed methane wellhead pipe head big four 35 vertical axis 1 m position, truss body 4 and adjusting pull rod 7 through the pin shaft 6 fixedly installed on the base 8, wellhead guide pulley 1 through the pulley bearing support 2 is fixedly installed on the top platform 3, safety operation platform 5 is installed on the truss body 4, ribas cylinder 14 is fixedly installed on the mobile base 11 by cylinder bearing support, the mobile base 11 is fixedly installed with motor 19 and speed reducer 17, ribas cylinder 14 is connected by cylinder bearing support through first connecting shaft 16 and the output shaft of speed reducer 17, the output shaft is connected through second connecting shaft 20 and the input shaft of speed reducer 17, motor 19 drives ribas cylinder 14 to rotate through speed reducer 17, mobile base 11 is assembled on the lower limit rail through the bottom of the roller and horizontal reverse wheel 13, the roller is provided with upper limit rail, the guide rail is composed of lower limit rail and upper limit rail, mobile base 11 can move along the lower limit rail, the output shaft of speed reducer 17 is hollow shaft, one end of the hollow output shaft is connected with the cylinder through the first connecting shaft 16, the other end of the hollow output shaft is fixedly connected with the nut, the nut is screwed on the lead screw of the rope arranging mechanism 18, the rope arranging mechanism 18 is fixedly installed on the base 8 through the support frame, the nut and the input shaft are driven to move linearly along the lead screw of the rope arranging mechanism 18 synchronously with the rotation of the lead screw and the cylinder during the rotation of the input shaft of speed reducer 17, motor 19 is connected with the control system and controlled by the control system.

[0054] After the no-load debugging of the drum type machine drainage and production device is completed, the second sealing plunger 25 and the upper joint of the carbon fiber continuous oil rod 41 are hung and manually debugged through the screw connection.

[0055] The working mode of the present example

[0056] First step, according to the geological scheme design of the coalbed methane well, the process scheme design of the machine drainage and production lifting system is carried out;

[0057] The lifting system process scheme design includes pump hanging depth, pump diameter, stroke, stroke number, carbon fiber continuous pumping rod 44 mixed rod string combination, downhole process pipe column structure, and determination of the drum type machine drainage and production device model.

[0058] Second step, according to the process scheme design requirements, the process pipe column part of the directional flow channel plunger type gas and water separation system, the pumping rod structure, the downhole operation construction of the directional flow channel plunger type gas and water separation system in the drainage and production lifting system are carried out respectively.

[0059] Third step, install the drum type machine drainage and production device;

[0060] Install the drum-type machine extraction and production device base 8, install the wellhead pulley truss support body 4 on the device base 8, adjust the truss support body 4 to adjust the well positioning adjustment pull rod 7. In this embodiment, the adjustment pull rod 7 is composed of a threaded rod and a threaded sleeve, and the threaded rod and the threaded sleeve can realize the telescopic function. Install the lower limit track, place the moving base 11 on the track, and install the motor 19, the speed reducer 17, and the Libas drum 14 on the moving trolley. Connect the control cabinet system and the motor 19.

[0061] Fourth step, debugging the drum-type machine extraction and production device

[0062] The signals of the upper dead point limit switch, the origin switch, the lower dead point limit switch, the encoder, the load sensor, the pressure transmitter, the emergency shut-off valve, and the flowmeter, and the manual-electric integrated brake 21 are respectively connected to the DI, A / D, and RS485 interfaces of the control core RTU 34 through wires. The display screen in the control system is started through man-machine dialogue. First, enter the initialization screen menu to complete the initialization operation of the drum-type machine extraction and production device, and then click to enter the main menu for manual debugging, which is mainly used for on-site manual debugging.

[0063] Fifth step, connect the cable joint 23 of the load-bearing rope 22 to the first sealing plunger 24 and the second sealing plunger 25 in turn, and then wrap and fix one end of the load-bearing rope 22 on the drum. After completion, the second sealing plunger 25 and the upper joint of the carbon fiber continuous oil rod 41 are connected through a thread. Then click to enter the main menu of the display screen in the control system for manual debugging, which is mainly used for on-site manual debugging. Detect the instrument signal once, manually test and adjust the oil well minimum / maximum stroke and the anti-collision distance, determine the upper dead point of the extraction and production device, i.e. the origin position and the lower dead point limit position, and manually test the maximum stroke.

[0064] Sixth step, trial operation

[0065] Click to enter the "intelligent control mode" menu in the main menu of the display screen in the control system to realize the automatic operation of the oil well in the normal mode. The running parameters are controlled according to the parameters set in the initialization. The controller will confirm the current position and direction according to the motor 19 or drum rotation pulse detection, and slow down and reverse when approaching the deceleration point.

[0066] Seventh step, click to enter the "control daily water discharge" method in the "intelligent control mode" menu in the main menu of the display screen in the control system. Through man-machine dialogue, manually preset the daily water production of the control system. The control system adjusts the extraction and production system according to the changes of the bottom hole flowing pressure or the liquid level to find the extraction and production lifting capacity that can meet the control target, i.e. the liquid discharge capacity of the oil pump.

[0067] The eighth step, during the well repairing operation, only need to adjust the truss body 4 to be vertical to the ground base by adjusting the pull rod 7, and then the pulley can be adjusted to be more than 700cm away from the wellhead axis.

[0068] The above only is the preferred embodiment of the present application, and does not limit the present application, any modification, equivalent replacement, improvement, 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 drainage gas recovery lift system for a coal bed methane well, characterized by: The device comprises a drum-type machine pumping and drainage device and a machine pumping and drainage gas lifting system; The output end of the drum-type machine pumping and drainage device is connected with the load rope (22) of the machine pumping and drainage gas lifting system; The machine pumping and drainage gas lifting system comprises a first oil pipe structure (36), an oil pumping rod structure and a directional flow channel plunger type gas and water separation system, the first oil pipe structure (36) is arranged in a gas well shaft, the oil pumping rod structure is arranged in the first oil pipe structure (36), the bottom of the oil pumping rod structure is connected with a continuous oil rod (41) of the directional flow channel plunger type gas and water separation system, and the top of the directional flow channel plunger type gas and water separation system is detachably connected with the first oil pipe structure (36). The oil pumping rod structure comprises a load rope (22), a sealing sleeve (28), a flow guide short circuit (29), a positioning short circuit (30) and a dynamic sealing structure, one end of the load rope (22) is connected with the output end of the drum-type machine pumping and drainage device, the other end of the load rope (22) is connected with the dynamic sealing structure, the dynamic sealing structure is slidably arranged on the inner side of the sealing sleeve (28), the dynamic sealing structure is connected with the continuous oil rod (41), the bottom of the sealing sleeve (28) is provided with the flow guide short circuit (29) and the positioning short circuit (30), and the positioning short circuit (30) is detachably connected with the bottom of the first oil pipe structure (36). The dynamic sealing structure comprises a first sealing plunger (24) and a second sealing plunger (25), the top of the first sealing plunger (24) is connected with the load rope (22) through a cable joint (23), the bottom of the first sealing plunger (24) is provided with the second sealing plunger (25), and the second sealing plunger (25) is connected with the continuous oil rod (41). The directional flow channel plunger type gas and water separation system comprises a second oil pipe structure, a continuous oil rod (41), a connecting structure, an oil pumping rod (44), a pump pulling rod (45), a conical pump cylinder (37), a double-closed structure plunger (46), a disc type liquid and gas separator (39) and a self-cleaning guide fixed valve (38), the top of the second oil pipe structure is detachably connected with the bottom of the first oil pipe structure (36), the bottom of the second oil pipe structure is connected with the conical pump cylinder (37), the bottom of the conical pump cylinder (37) is provided with the disc type liquid and gas separator (39), the top of the continuous oil rod (41) is connected with the second sealing plunger (25), the bottom of the continuous oil rod (41) is connected with the oil pumping rod (44) through the connecting structure, the bottom of the oil pumping rod (44) is connected with the double-closed structure plunger (46) through the pump pulling rod (45), the disc type liquid and gas separator (39) and the self-cleaning guide fixed valve (38) are both located below the double-closed structure plunger (46), the self-cleaning guide fixed valve (38) is arranged between the disc type liquid and gas separator (39) and the double-closed structure plunger (46), and the double-closed structure plunger (46) and the self-cleaning guide fixed valve (38) are both arranged in the conical pump cylinder (37).

2. The drainages gas recovery lifting system for coal bed methane well according to claim 1, characterized in that: The inclination angle of the side wall of the conical pump cylinder (37) is 5°-10°.

3. A gas lift system for coal bed methane wells according to any one of claims 1-2, characterized in that: The drum type machine pumping device comprises a truss support (4), a well mouth guide pulley (1), an adjusting pull rod (7), a foundation base (8), a drum structure, a motor (19), a speed reducer (17), a rope discharging mechanism (18) and a moving base (11), the truss support (4) is provided with the well mouth guide pulley (1) at the top, the truss support (4) is hinged to the foundation base (8) at the bottom, one end of the adjusting pull rod (7) is hinged to the top of the truss support (4), the bottom of the adjusting pull rod (7) is hinged to the foundation base (8), the moving base (11) is connected to the foundation base (8) through a sliding structure, the drum structure, the motor (19) and the speed reducer (17) are all arranged on the moving base (11), the output end of the motor (19) is connected to the input shaft of the speed reducer (17), the output shaft of the speed reducer (17) is a hollow shaft, one end of the output shaft of the speed reducer (17) is connected to the drum structure, the other end of the output shaft of the speed reducer (17) is threadedly connected to the threaded end of the rope discharging mechanism (18), the fixed end of the rope discharging mechanism (18) is arranged on the foundation base (8), the load bearing rope (22) is wound on the drum structure, and the well mouth guide pulley (1) is used for guiding the load bearing rope (22).

4. The drain and gas recovery lift system for a coal bed methane well of claim 3, wherein: The drum type machine pumping device further comprises a safety operation platform (5), and the safety operation platform (5) is arranged on the truss support (4).

5. The drain and gas recovery lift system for a coal bed methane well of claim 3, wherein: The sliding structure comprises two parallel guide rails, the moving base (11) is slidably connected to the two guide rails through moving rollers (12) arranged on the sides of the moving base (11), and the sides of the moving base (11) are provided with radial limiting rollers.

6. A drain and gas recovery lift system for a coal bed methane well as defined in claim 5, wherein: The guide rail is provided with an origin switch, and an upper limit switch and a lower limit switch are arranged at the front end and the rear end of the guide rail respectively.

7. The drain and gas recovery lift system for a coal bed methane well of claim 3, wherein: The drum structure comprises a Ribas drum (14) and two drum supports (15), the Ribas drum (14) is connected to the upper end surface of the moving base (11) through the two drum supports (15), and the Ribas drum (14) is used for winding the load bearing rope (22).

8. The drain and gas recovery lift system for a coal bed methane well of claim 3, wherein: The jet backflow device (33) comprises a suction inlet, a power gas source interface and a diffusion pipe, the suction inlet is arranged at the inlet end of the diffusion pipe, the power gas source interface is arranged at the inlet end of the diffusion pipe, the outlet end of the diffusion pipe is connected to the gas production pipeline through a pipeline, and the suction inlet is connected to the overflow outlet of the Christmas tree four-way valve (27).

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