CN215485965U

CN215485965U - Coal bed gas well diaphragm pump production string

Info

Publication number: CN215485965U
Application number: CN202121363436.9U
Authority: CN
Inventors: 胡皓; 秦绍锋; 郭明强; 李忠城; 张守仁; 王小东; 孔鹏; 刘广景; 张亚飞; 陈彦丽; 徐最; 刘国明; 阚亮; 马歆宁; 常风琛
Original assignee: China United Coalbed Methane Corp Ltd
Current assignee: China United Coalbed Methane Corp Ltd
Priority date: 2021-06-18
Filing date: 2021-06-18
Publication date: 2022-01-11
Anticipated expiration: 2031-06-18

Abstract

The utility model discloses a coal bed gas well diaphragm pump production string which comprises a sleeve, an oil pipe, a liquid storage pipe assembly and a diaphragm pump, wherein the sleeve is fixedly connected with the oil pipe; the oil pipe is at least partially positioned in the casing, and a first space is formed between the oil pipe and the casing; the lower end of the oil pipe is closed; the diaphragm pump comprises a pump body, wherein at least part of the pump body is positioned inside the oil pipe; the liquid storage pipe assembly is positioned inside the sleeve and below the oil pipe, a screen structure is arranged on the local pipe wall of the liquid storage pipe assembly, a liquid storage cavity of the liquid storage pipe assembly is communicated with the first space through the screen structure, and a suction inlet of the pump body is communicated with the liquid storage cavity of the liquid storage pipe assembly through a fluid channel arranged on the oil pipe; an outlet of a pump cavity of the diaphragm pump is communicated with an inner cavity of the oil pipe; according to the utility model, the suction inlet of the diaphragm pump is positioned below the oil pipe, so that the maximum liquid descending of the coal-bed gas well can be realized.

Description

Coal bed gas well diaphragm pump production string

Technical Field

The utility model relates to the technical field of coal bed gas exploitation, in particular to a coal bed gas well diaphragm pump production pipe column.

Background

In the coal bed gas mining process, a sucker rod pump is a common drainage and mining device. In the up-and-down movement process of the sucker rod, the sucker rod is contacted with the oil pipe, so that the sucker rod is rubbed with the oil pipe and even broken. The sucker rod can also generate eccentric wear with the inner wall of the oil pipe, and the eccentric wear between the sucker rod and the oil pipe can cause the sucker rod to break off from the oil pipe, thereby influencing the normal exploitation of the coal bed gas.

In recent years, rodless equipment gradually becomes the mainstream of coal bed gas production equipment, such as a hydraulic piston pump, a hydraulic jet pump, an electric submersible screw pump, a gas lift, a diaphragm pump and the like. The diaphragm has good trafficability characteristic and low energy consumption and occupies certain advantages when applied to the coal-bed gas well, however, the suction inlet of the conventional diaphragm pump is positioned at the upper end of the pump for a certain distance, so that the problem of insufficient liquid drop exists, the whole production capacity of the gas well is difficult to release, and the process applicability is limited to a certain extent.

Therefore, how to achieve sufficient liquid reduction of the diaphragm pump gas production process becomes a technical problem to be solved urgently by the technical personnel in the field.

SUMMERY OF THE UTILITY MODEL

The utility model aims to improve the performance of the diaphragm pump gas production process.

The utility model provides a coal bed gas well diaphragm pump production string which comprises a casing, an oil pipe and a diaphragm pump; wherein,

the oil pipe is at least partially positioned inside the casing pipe, and a first space is formed between the oil pipe and the casing pipe; the lower end of the oil pipe is closed; the diaphragm pump comprises a pump body at least partially located inside the oil pipe;

the pump body is characterized by further comprising a liquid storage pipe assembly, the liquid storage pipe assembly is located inside the sleeve and below the oil pipe, a screen structure is arranged on the local pipe wall of the liquid storage pipe assembly, a liquid storage cavity of the liquid storage pipe assembly is communicated with the first space through the screen structure, and a suction inlet of the pump body is communicated with the liquid storage cavity of the liquid storage pipe assembly through a fluid channel arranged on the oil pipe; and an outlet of a pump cavity of the diaphragm pump is communicated with an inner cavity of the oil pipe.

According to the utility model, the suction inlet of the diaphragm pump is positioned below the oil pipe, so that the maximum liquid descending of the coal-bed gas well can be realized.

Optionally, the pump further comprises a short section, the upper end of the short section is circumferentially and hermetically connected with the pump body, the lower end of the short section penetrates through the closed end of the oil pipe and is circumferentially and hermetically connected above the screen structure of the liquid storage pipe assembly, and a suction inlet of the pump body is connected with a liquid storage cavity of the liquid storage pipe assembly through a channel formed inside the short section.

Optionally, the liquid storage pipe assembly comprises a main pipe, a sieve pipe and a central pipe, the sieve pipe is located in the sieve pipe, the sieve pipe is connected to the upper portion of the main pipe, the central pipe is a hollow pipe with two open ends, the central pipe is located inside the main pipe and the sieve pipe, the upper end of the main pipe is open, the lower end of the main pipe is closed, the upper end of the central pipe is connected with the nipple or the oil pipe or the sieve pipe in a positioning mode, and a suction inlet of the pump body is communicated with an inner cavity of the main pipe through an inner channel of the nipple.

Optionally, the lower end of the oil pipe is of an open structure, a clamping seat joint is installed on the open structure, a mounting hole is formed in the clamping seat joint, the short section is circumferentially and hermetically installed in the mounting hole, and the sieve pipe is in threaded connection with the clamping seat joint.

Optionally, the mounting hole includes the taper hole section and the cylinder hole section that meet, the nipple joint includes taper pipe section and cylinder shaft section, the taper pipe section with the cooperation installation of taper hole section and be provided with the sealing washer between the two, cylinder hole section and corresponding the cooperation installation of cylinder shaft section.

Optionally, a plug is arranged at the lower end of the main pipe to form a closed structure;

or/, the outer wall of the screen is also provided with a steel screen.

Optionally, the diameter of the central tube ranges from 30mm to 40mm, and the diameter of the main tube 9 ranges from 68mm to 73 mm.

Optionally, the upper end of the nipple is provided with an external thread section, and the external thread section is in threaded connection with the pump body.

Optionally, the system further comprises a central rod and a second-stage hanger, the upper end of the central rod is fixed to the second-stage hanger, a part of the central rod extends into the oil pipe, and the diaphragm pump is fixed to the central rod;

or/and the cable of the diaphragm pump is fixed to the central rod.

Optionally, the device further comprises a first-stage hanger, a wellhead four-way, a second-stage hanger and a wellhead three-way, wherein the wellhead four-way supports the first-stage hanger, the wellhead three-way supports the second-stage hanger, the casing supports the wellhead four-way, and the first-stage hanger is communicated with an external corresponding pipeline through the wellhead four-way.

Drawings

FIG. 1 is a schematic structural diagram of a diaphragm pump production string of a coal-bed gas well in one embodiment of the utility model;

FIG. 2 is a schematic structural diagram of a short section in an embodiment of the present invention.

Wherein, the one-to-one correspondence between the reference numbers and the part names in fig. 1 is as follows:

the device comprises a casing pipe 1, an oil pipe 2, a diaphragm pump 3, a central rod 4, a short section 5, a tapered pipe section 51, a cylindrical shaft section 52, an external thread section 5a, a clamping seat joint 6, a sieve pipe 7, a central pipe 8, a main pipe 9, a plug 10, a wellhead cross joint 11, a wellhead cross joint 12, a wellhead cross joint 13, a first-stage hanger and a second-stage hanger 14.

Detailed Description

In order to make the technical solutions of the present invention better understood by those skilled in the art, the present invention will be further described in detail with reference to the accompanying drawings and specific embodiments.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a diaphragm pump production string of a coal-bed gas well according to an embodiment of the present invention.

The utility model provides a production string of a diaphragm pump 3 of a coal bed gas well, which comprises a casing 1, an oil pipe 2 and the diaphragm pump 3.

The structure of the casing 1 can refer to the prior art, and the casing 1 can be suspended and fixedly connected with a wellhead four-way 11 through a first-stage hanger 13. The wellhead cross 11 is connected with corresponding external pipelines.

According to the utility model, the oil pipe 2 is at least partially positioned inside the casing 1, and a first space is formed between the oil pipe and the casing. The lower end of the oil pipe 2 is closed, the lower end of the oil pipe 2 can be directly processed into a closed structure, of course, the lower end of the oil pipe 2 can also be realized by plugging a plugging block in the open structure, and a specific embodiment will be described in detail later.

The diaphragm pump 3 comprises a pump body, and the pump body is at least partially positioned inside the oil pipe 2; the diaphragm pump 3 specifically comprises a suction inlet, a part located at the suction inlet and used at night, a pump cavity, a discharge valve and the like, and when the diaphragm pump works, under the action of pumping power, external liquid enters the pump cavity from a liquid inlet valve of the suction inlet, and is discharged from the discharge valve after being pressurized by the pump cavity.

The production string of the coal bed gas well diaphragm pump 3 can further comprise a liquid storage pipe assembly, the liquid storage pipe assembly is positioned inside the sleeve 1 and below the oil pipe 2, a screen structure is arranged on the local pipe wall of the liquid storage pipe assembly, a liquid storage cavity of the liquid storage pipe assembly is communicated with the first space through the screen structure, and a suction inlet of the pump body is communicated with the liquid storage cavity of the liquid storage pipe assembly through a fluid channel arranged on the oil pipe 2; the outlet of the pump cavity of the diaphragm pump 3 is communicated with the inner cavity of the oil pipe 2.

According to the utility model, the suction inlet of the diaphragm pump 3 is positioned below the oil pipe 2, so that the maximum liquid descending of the coal-bed gas well can be realized.

Referring to fig. 2, fig. 2 is a schematic structural diagram of a short joint according to an embodiment of the present invention.

In a specific embodiment, 3 production tubular columns of coal bed gas well diaphragm pump can also include nipple joint 5, the upper end circumference sealing connection pump body of nipple joint 5, wherein nipple joint 5 can pass through threaded connection with the pump body, the nipple joint 5 promptly and with the pump body the two be provided with matched with helicitic texture respectively, for example the upper end of nipple joint 5 is provided with the external screw thread section, the pump body is provided with the internal thread.

The lower end of the short section 5 penetrates through the closed end of the oil pipe 2 and is circumferentially and hermetically connected above the screen mesh structure of the liquid storage pipe assembly, and the suction inlet of the pump body is connected with the liquid storage cavity of the liquid storage pipe assembly through a channel formed in the short section 5.

The suction end of the diaphragm pump 3 can be supported in the oil pipe 2 in an auxiliary mode through the short section 5, and the working stability of the diaphragm pump 3 is improved.

Specifically, the liquid storage pipe assembly of the production pipe column of the coal bed gas well diaphragm pump 3 can further comprise a liquid storage pipe assembly which comprises a main pipe 9, a sieve pipe 7 and a central pipe 8, wherein the sieve pipe 7 is located on the sieve pipe 7, the sieve pipe 7 is connected above the main pipe 9, the central pipe 8 is a hollow pipe with two open ends, the central pipe 8 is located inside the main pipe 9 and the sieve pipe 7, the upper end of the main pipe 9 is open, the lower end of the main pipe is closed, and the lower end of the main pipe 9 can be provided with a plug 10 for forming a closed structure.

The upper end of the main pipe 9 is connected to the short section 5 or the closed end of the oil pipe 2, the upper end of the central pipe 8 is connected with the short section 5 or the oil pipe 2 or the sieve pipe 7 in a positioning mode, and a suction inlet of the pump body is communicated with an inner cavity of the main pipe 9 through an inner channel of the short section 5 and the central pipe 8.

During operation, start the operation of diaphragm pump 3, the inside water of first space, buggy, gaseous annular space that gets into to be responsible for 9 and the two formation of center tube through the screen pipe structure, in this annular space: gas upward flow, flow into first space again through the screen pipe structure and along first space upward flow, water, buggy downward flow, flow to 8 bottoms of center tubes after, water changes the flow direction, along 8 inside upward flows of center tubes, get into the pump chamber of diaphragm pump 3 through

nipple joint

5, 3 feed liquor valves of diaphragm pump, discharge along 2 inner chambers of oil pipe to ground from the bleeder valve after 3 pressurizations of diaphragm pump, the buggy deposits to the bottom of being responsible for 9 under the action of gravity. Therefore, the water flowing into the oil pipe 2 is purified water, the gas content is greatly reduced, and the air lock fault can be effectively prevented.

In a specific embodiment, the lower end of the oil pipe 2 is of an open structure, the open structure is provided with a clamping seat joint 6, the clamping seat joint 6 is provided with a mounting hole, the short section 5 is circumferentially and hermetically mounted in the mounting hole, and the sieve pipe is in threaded connection with the clamping seat joint 6.

Go into the outer tubular column of using oil pipe 2 as the main part earlier in-process, from top to bottom do in proper order: oil pipe 2, cassette joint 6, be responsible for 9, screen pipe, end cap 10,

center tube

8, 2 upper ends of oil pipe are connected with first order hanger 13, sit and hang in well head cross 11, and the lower tip is connected with cassette joint 6 (the two can screw thread sealing connection, certainly also can be other modes), and the outside and the stock solution pipe assembly of cassette joint 6 lower extreme are connected, sit through first order hanger 13 after down to the design degree of depth and hang in well head cross 11.

The outer end part of the clamping seat joint 6 can be connected with the sieve tube in a sealing mode (the two can be in threaded connection, and certainly can also be connected in other modes), the inner part of the lower end of the clamping seat joint is connected with the upper end of the central tube 8 through threads, and the bottom end of the central tube 8 has a certain distance from the plug 10.

After the completion is gone into down to outer tubular column, go into the inlayer tubular column down, from top to bottom do in proper order: well core rod 4, diaphragm pump 3, nipple joint 5, 4 lower extremes of well core rod and 3 threaded connection of diaphragm pump, the upper end is connected with second grade hanger 14 and is sat and hang in well

head tee bend

12, 3 lower extremes of diaphragm pump pass through the screw thread part and are connected with nipple joint 5, the outside cover has circular seal ring in the seal groove of nipple joint 5 lower extreme, down to the cassette joint 6 after, in nipple joint 5 got into cassette joint 6, push down a basis weight, realize sealing between first space and the 2 inner chambers of oil pipe through extrusion circular seal ring and separate.

Specifically, the mounting hole of the cassette joint 6 comprises a conical hole section and a cylindrical hole section which are connected, the short section 5 comprises a conical pipe section 51 and a cylindrical shaft section 52, the conical pipe section 51 and the conical hole section are installed in a matched mode, a sealing ring is arranged between the conical pipe section 51 and the conical hole section, and the cylindrical hole section and the corresponding cylindrical shaft section 52 are installed in a matched mode. The sealing ring may be a rubber seal.

The upper end part of a short section 5 of a production pipe column of the coal bed gas well diaphragm pump 3 is provided with an external thread section 5a, and the external thread section 5a is in threaded connection with the pump body.

As mentioned above, the production string of the coal bed gas well diaphragm pump 3 further comprises the central rod 4 and the second-stage hanger 14, the upper end portion of the central rod 4 is fixed on the second-stage hanger 14, the part of the central rod 4 extends into the oil pipe 2, and the diaphragm pump 3 is fixed on the central rod 4.

In the above embodiments, the cable of the membrane pump 3 may be fixed to the central rod 4.

The length of the sub 5, screen can be determined according to the specific application, for example, in one embodiment the screen is about 2-3 m. The length of the sieve tube can be increased or shortened according to the water yield so as to adjust the liquid inlet capacity of the sieve tube.

The diameter range of the central pipe 8 is 30-40 mm, the diameter range of the main pipe 99 is 68-73 mm, the diameter difference between the main pipe 9 and the central pipe 8 is increased, the flow velocity of fluid in an annular space formed by the main pipe 9 and the central pipe 8 can be reduced, gas-liquid separation is facilitated, the diameter of the central pipe 88 is increased, the flow velocity of fluid in the central pipe can be reduced, coal dust precipitation is facilitated, and the coal-bed gas well can be set according to specific requirements of a coal-bed gas well.

In the above embodiments, the outer wall of the sieve tube is provided with a steel sieve. The aperture of the screen is selected according to actual needs, and is not particularly limited herein.

In order to improve the filtering effect on the pulverized coal, the outer wall of the sieve tube 7 is provided with a steel filter screen. The pore size of the sand screen is selected according to actual needs, and is not particularly limited herein.

The coal bed gas well diaphragm pump production pipe column provided by the utility model is described in detail. The principles and embodiments of the present invention are explained herein using specific examples, which are presented only to assist in understanding the method and its core concepts. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention.

Claims

1. A coal bed gas well diaphragm pump production pipe column is characterized by comprising a casing (1), an oil pipe (2) and a diaphragm pump (3); wherein,

the oil pipe (2) is at least partially positioned inside the casing (1), and a first space is formed between the oil pipe and the casing; the lower end of the oil pipe (2) is closed; the diaphragm pump (3) comprises a pump body which is at least partially located inside the oil pipe (2);

the pump body is characterized by further comprising a liquid storage pipe assembly, the liquid storage pipe assembly is located inside the sleeve (1) and below the oil pipe (2), a screen structure is arranged on a local pipe wall of the liquid storage pipe assembly, a liquid storage cavity of the liquid storage pipe assembly is communicated with the first space through the screen structure, and a suction inlet of the pump body is communicated with the liquid storage cavity of the liquid storage pipe assembly through a fluid channel arranged on the oil pipe (2); and an outlet of a pump cavity of the diaphragm pump (3) is communicated with an inner cavity of the oil pipe (2).

2. The diaphragm pump production string for the coal-bed gas well as defined in claim 1, further comprising a short joint (5), wherein the upper end of the short joint (5) is circumferentially and hermetically connected with the pump body, the lower end of the short joint (5) penetrates through the closed end of the oil pipe (2) and is circumferentially and hermetically connected above the screen structure of the liquid storage pipe assembly, and the suction inlet of the pump body is connected with the liquid storage cavity of the liquid storage pipe assembly through a channel formed in the short joint (5).

3. The diaphragm pump production string for coal bed gas well as defined in claim 2, wherein the liquid storage pipe assembly comprises a main pipe (9), a screen pipe (7) and a central pipe (8), the screen structure is located on the screen pipe (7), the screen pipe (7) is connected above the main pipe (9), the central pipe (8) is a hollow pipe with two open ends, the central pipe (8) is located inside the main pipe (9) and the screen pipe (7), the main pipe (9) is open at the upper end and closed at the lower end, the upper end of the central pipe (8) is connected with the nipple (5) or the oil pipe (2) or the screen pipe (7) in a positioning manner, and the suction inlet of the pump body is communicated with the inner cavity of the main pipe (9) through the inner channel of the nipple (5) and the central pipe (8).

4. The diaphragm pump production string for coal bed gas wells as defined in claim 3, wherein the lower end of the oil pipe (2) is an open structure, the open structure is provided with a clamping seat joint (6), the clamping seat joint (6) is provided with a mounting hole, the short joint (5) is circumferentially and hermetically mounted in the mounting hole, and the sieve pipe (7) is in threaded connection with the clamping seat joint (6).

5. The diaphragm pump production string for coal-bed gas wells, as set forth in claim 4, characterized in that the installation hole comprises a tapered bore section and a cylindrical bore section which are connected, the nipple (5) comprises a tapered bore section (51) and a cylindrical shaft section (52), the tapered bore section (51) and the tapered bore section are installed in a matching manner with a sealing ring arranged therebetween, and the cylindrical bore section and the corresponding cylindrical shaft section (52) are installed in a matching manner.

6. The diaphragm pump production string for coal-bed gas wells as defined in claim 3, wherein the lower end of the main pipe (9) is provided with a plug for forming a closed structure;

or/and the outer wall of the screen is also provided with a steel screen.

7. Coal-bed gas well diaphragm pump production string according to any of claims 3 to 6, characterized in that the central pipe (8) has a diameter in the range of 30mm to 40mm and the main pipe (9) has a diameter in the range of 68mm to 73 mm.

8. The coal-bed gas well diaphragm pump production string according to any one of claims 2 to 6, characterized in that the upper end of the nipple (5) is provided with an external threaded section (5a), and the external threaded section (5a) is in threaded connection with the pump body.

9. The diaphragm pump production string for coal-bed gas wells according to any one of claims 1 to 6, characterized by further comprising a central rod (4) and a second-stage hanger, wherein the upper end of the central rod (4) is fixed to the second-stage hanger, a part of the central rod (4) extends into the oil pipe (2), and the diaphragm pump (3) is fixed to the central rod (4);

or/and the cable of the diaphragm pump (3) is fixed to the central rod (4).

10. The diaphragm pump production string for coal-bed gas wells as defined in claim 9, further comprising a first-stage hanger, a wellhead four-way, and a wellhead three-way, wherein the wellhead four-way supports the first-stage hanger, the wellhead three-way supports the second-stage hanger, the casing (1) is supported by the wellhead four-way, and the first-stage hanger is communicated with an external corresponding pipeline through the wellhead four-way.