Wellhead device for plunger gas lift drainage gas recovery and using method

Abstract

The invention belongs to the technical field of gas production devices, and particularly provides a plunger gas lift drainage gas production wellhead device and a using method.The plunger gas lift drainage gas production wellhead device comprises a plunger, a gas production tree, an oil pipe, a pressure transmitter, a first pipeline assembly and a control valve and further comprises a simple wellhead assembly and a buffer positioner, and the buffer positioner is connected into the oil pipe; the plunger is located in the oil pipe above the buffer positioner, the gas production tree is connected to the oil pipe on the buffer positioner, the simple wellhead assembly is connected to the oil pipe above the gas production tree, the first pipeline assembly is connected to the side face of the gas production tree, and the pressure transmitter and the control valve are connected to the first pipeline assembly. The problems that an existing wellhead device comprises numerous components and pipelines, the structure is complex, the manufacturing and operation difficulty is large, the occupied area is large, the workload is large, and the production efficiency is low are solved. Under the condition that functions and performance are not reduced, the manufacturing difficulty of the device is reduced, the production cycle is shortened, the workload is reduced, and the production efficiency is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of gas production devices, and in particular relates to a wellhead device for plunger gas lift water drainage and gas production and a use method thereof. Background Art

[0002] The existing plunger gas lift drainage and gas production device includes many components and pipelines, has a complex structure, is difficult to manufacture and operate, occupies a large area, has a large workload, and has low production efficiency. There is an urgent need for a device that can reduce the manufacturing difficulty of the plunger gas lift drainage and gas production device, reduce the working cycle and workload, and improve production efficiency without reducing functions or performance.

[0003] The Chinese patent document with the publication number CN113669240A discloses a plunger and a wellhead gas production system, wherein an axially extending long hole is provided inside the plunger, a first liquid inlet channel connected to the long hole is provided at one end of the plunger, and an atomization channel connected to the long hole is provided radially in the plunger; a plugging member is provided in the long hole, and the plugging member is slidably sealed with the inner wall of the long hole; the plugging member is configured to: move from the equilibrium state to the atomization state under the action of pressure, so that the liquid in the long hole is ejected from the atomization channel. When the plunger of the present application works in the well, it can move up and down under the action of the pressure in the well to discharge the accumulated water in the well, and the accumulated water below the plunger can enter the top of the plunger through the atomization channel and be pushed out of the wellhead by the plunger, thereby improving the drainage efficiency of the plunger. However, the document solves the problem of using the plunger to improve the drainage efficiency, and does not solve the problem that the wellhead device of the present application includes many components and pipelines, a complex structure, a large manufacturing and operation difficulty, a large area, a large workload, and a low production efficiency. Summary of the invention

[0004] The present invention provides a plunger gas lift wellhead device for drainage and gas production and a method of use thereof, aiming to overcome the problems in the prior art that the wellhead device includes numerous components and pipelines, has a complex structure, is difficult to manufacture and operate, occupies a large area, has a large workload, and has low production efficiency.

[0005] To this end, the present invention provides a wellhead device for plunger gas lift water drainage and gas production, including a plunger, a gas production tree, an oil pipe, a pressure transmitter, a pipeline assembly and a control valve, and also includes a simple wellhead assembly and a buffer positioner. The buffer positioner is connected to the oil pipe, and the plunger is located in the oil pipe above the buffer positioner. The oil pipe on the buffer positioner is connected to the gas production tree, and the oil pipe above the gas production tree is connected to the simple wellhead assembly. The side of the gas production tree is connected to the pipeline assembly, and the pipeline assembly is connected to the pressure transmitter and the control valve.

[0006] Preferably, the simple wellhead assembly comprises a buffer spring and a blowout preventer, the buffer spring is connected to the blowout preventer, the lower part of the blowout preventer is internally connected to the oil pipe, and the lower part of the blowout preventer is externally connected to the gas production tree.

[0007] Preferably, the simple wellhead assembly further comprises an impact block, and the impact block is connected to the lower end of the buffer spring.

[0008] Preferably, the simple wellhead assembly further comprises a flange seat, the upper end of the flange seat is connected to the impact block, the upper part of the flange seat is sleeved in the lower part of the blowout preventer, and the outer side of the lower end of the flange seat is connected to the gas production tree.

[0009] Preferably, the simple wellhead assembly further comprises a locking ring, and the lower end of the buffer spring is connected to the impact block via the locking ring.

[0010] Preferably, the simple wellhead assembly further comprises a catcher, which is connected to the side of the flange seat and is located below the blowout preventer.

[0011] Preferably, the simple wellhead assembly further comprises a handle, and the handle is connected to the outer side of the upper end of the blowout preventer.

[0012] Preferably, the simple wellhead assembly further comprises a sealing ring, and the sealing ring is sleeved between the flange seat and the blowout preventer cap.

[0013] Preferably, the wellhead device for plunger gas lift drainage and gas production also includes a retaining ring, which is sleeved between the flange seat and the blowout preventer.

[0014] A method for using a wellhead device for plunger gas lift water drainage and gas production comprises the following steps:

[0015] During gas production, after the control valve is opened, the downhole pressure difference pushes the plunger upward to the simple wellhead assembly and contacts the impact block, and the buffer spring prevents the plunger from moving upward; the downhole liquid and gas are discharged to the outside of the well through the pipeline assembly, and the control valve is closed after the tubing pressure is reduced, and the plunger moves downward to the upper end of the buffer positioner, and the plunger stops moving; a cycle of plunger gas lift drainage and gas production is completed, and the above actions are repeated after the formation pressure is restored to complete gas production;

[0016] When the plunger is released, the gas tree is closed, the blowout preventer is removed, the catcher is opened, the plunger is released, the blowout preventer is installed, the gas tree is opened, the catcher releases the plunger, and the plunger moves down to the upper end of the buffer positioner to complete the plunger release.

[0017] Beneficial effects of the present invention:

[0018] 1. The plunger gas lift drainage and gas production wellhead device and use method provided by the present invention are as follows: during gas production, after the control valve is opened, the downhole pressure difference pushes the plunger upward to the simple wellhead assembly and contacts the impact block, and the buffer spring prevents the plunger from moving upward; the downhole liquid and gas are discharged to the outside of the well through the pipeline assembly, and the control valve is closed after the oil pipe pressure is reduced, the plunger moves downward to the upper end of the buffer positioner, and the plunger stops moving; a cycle of plunger gas lift drainage and gas production is completed, and the above actions are repeated after the formation pressure is restored to complete gas production; when the plunger is released, the gas production tree is closed, the blowout preventer is removed, the catcher is opened, the plunger is released, the catcher catches the plunger, the blowout preventer is installed, the gas production tree is opened, the catcher releases the plunger, the plunger moves downward to the upper end of the buffer positioner, and the plunger is released. After the plunger reaches the wellhead, it can achieve the functions of buffering, launching, sealing and blowout prevention; there is no need to set an additional buffer spring on the buffer positioner, and the simple wellhead assembly has a bypass-free design, which avoids problems such as on-site high-pressure pipeline welding procedures, hot work approval, and pipeline component leakage caused by welding deformation; it reduces production costs and shortens the construction period. Without reducing functions and performance, it reduces the difficulty of device manufacturing, reduces working cycles and workload, and improves production efficiency.

[0019] 2. In the plunger gas lift wellhead device for drainage and gas production provided by the present invention, the locking ring is connected to the blowout preventer through a thread, so that the buffer spring is in a slightly compressed state to prevent the buffer spring from being compressed or rebounded, and at the same time, it has a limiting effect on the buffer spring to prevent it from moving laterally. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention will be further described in detail below with reference to the accompanying drawings.

[0021] Figure 1 It is a schematic diagram of the structure of a wellhead device for plunger gas lift water drainage and gas production;

[0022] Figure 2 It is a structural schematic diagram of a simple wellhead assembly;

[0023] Figure 3 It is a schematic diagram of the structure of the connection between the buffer spring, the lock ring and the impact block;

[0024] Figure 4 It is a schematic diagram of the structure of the locking ring.

[0025] Explanation of the reference numerals: 1. Simple wellhead assembly; 2. Plunger; 3. Gas tree; 4. Oil pipe; 5. Buffer positioner; 6. Pressure transmitter; 7. Pipeline assembly one; 8. Control valve; 101. Buffer spring; 102. Stud; 103. Nut one; 104. Flange seat; 105. Set screw one; 106. Retaining ring; 107. Sealing ring; 108. Blowout preventer; 109. Impact block; 110. Locking ring; 111. Flange gasket; 112. Handle; 113. Nut two; 114. Catcher; 115. Set screw two. DETAILED DESCRIPTION

[0026] Embodiment 1:

[0027] like Figure 1-Figure 4 As shown, a wellhead device for plunger gas lift drainage gas production includes a plunger 2, a gas tree 3, an oil pipe 4, a pressure transmitter 6, a pipeline assembly 7 and a control valve 8, and is characterized in that it also includes a simple wellhead assembly 1 and a buffer positioner 5, the buffer positioner 5 is connected to the oil pipe 4, the plunger 2 is located in the oil pipe 4 above the buffer positioner 5, the oil pipe 4 on the buffer positioner 5 is connected to the gas tree 3, the oil pipe 4 above the gas tree 3 is connected to the simple wellhead assembly 1, the side of the gas tree 3 is connected to the pipeline assembly 7, and the pipeline assembly 7 is connected to the pressure transmitter 6 and the control valve 8.

[0028] Specifically, the control valve 8 includes an electric regulating valve, an emergency shut-off valve, a gate valve, etc.; the control valve 8 is an existing structure, and the original structure is not changed, and it is selected according to the situation; the pipeline assembly 7 is an existing high-pressure pipeline assembly; the simple wellhead assembly 1 is installed at the top of the gas production tree 3, and the buffer locator 5 is fixed on the inner wall of the oil pipe 4 at a predetermined position underground. When the control valve 8 is opened, the plunger 2 rises to the simple wellhead assembly 1 under the action of the underground pressure difference, and the plunger 2 carries the underground gas and liquid out through the pipeline assembly 7, keeping the control valve 8 open, and the gas and liquid continue to flow out, and the control valve 8 is closed after the pressure is reduced; after the control valve 8 is closed, the plunger 2 moves downward to the upper end of the buffer locator 5 under the action of its own gravity, completing a cycle of gas production.

[0029] The simple wellhead assembly 1 of the present invention has no bypass design, thereby avoiding problems such as on-site high-pressure pipeline welding procedures, hot work approval, and pipeline component leakage caused by welding deformation; reducing production costs and shortening the construction period.

[0030] The plunger 2 can have the functions of buffering, launching, sealing and blowout prevention after reaching the wellhead; there is no need to set an additional buffer spring on the buffer positioner 5, which reduces the difficulty of device manufacturing, reduces the short working cycle and workload, and improves production efficiency without reducing functions and performance.

[0031] Preferably, the simple wellhead assembly 1 comprises a buffer spring 101 and a blowout preventer 108 , the buffer spring 101 is connected to the blowout preventer 108 , the lower part of the blowout preventer 108 is internally connected to the oil pipe 4 , and the lower part of the blowout preventer 108 is externally connected to the gas production tree 3 .

[0032] The buffer spring 101 is used to prevent the plunger 2 from moving upward and has a buffering function; the spray-proof cap 108 prevents gas and liquid from spraying out and has a spray-proof function. Specifically, the upper end of the buffer spring 101 is connected to the spray-proof cap 108 through a nut 113.

[0033] Preferably, the simple wellhead assembly 1 further includes an impact block 109 , and the impact block 109 is connected to the lower end of the buffer spring 101 .

[0034] The impact block 109 serves to limit the plunger 2 , thereby preventing the plunger 2 from being stuck in the buffer spring 101 after impact.

[0035] Preferably, the simple wellhead assembly 1 further comprises a flange seat 104 , the upper end of the flange seat 104 is connected to the impact block 109 , the upper part of the flange seat 104 is sleeved in the lower part of the blowout preventer 108 , and the lower end of the flange seat 104 is connected to the gas production tree 3 on the outer side.

[0036] The anti-spray cap 108 is conveniently connected to the gas tree 3 through the flange seat 104, and the structure is simple and the installation and disassembly are convenient.

[0037] Preferably, a flange gasket 111 is disposed and connected to the lower side of the flange seat 104. The flange gasket 111 improves the sealing and fixing performance of the flange seat 104 and the gas tree 3.

[0038] Preferably, the side of the flange seat 104 is connected to the gas tree 3 through a combination of a stud 102 and a nut 103; the structure is simple and the installation and disassembly are convenient.

[0039] Preferably, the simple wellhead assembly 1 further includes a locking ring 110 , and the lower end of the buffer spring 101 is connected to the impact block 109 via the locking ring 110 .

[0040] The lock ring 110 is connected to the spray-proof cap 108 through threads, so that the buffer spring 101 is in a slightly compressed state to prevent the buffer spring 101 from being compressed or rebounded, and at the same time, it has a limiting effect on the buffer spring 101 to prevent it from moving laterally.

[0041] Preferably, the inner hole of the locking ring 110 is hexagonal, and may also be triangular, quadrilateral, pentagonal, etc.; the structure is simple, and can be selected according to actual conditions, and has good versatility.

[0042] Preferably, the simple wellhead assembly 1 further includes a catcher 114 , which is connected to a side of the flange seat 104 and is located below the blowout preventer 108 .

[0043] The catcher 114 includes a sleeve and a catch rod. The sleeve is horizontally arranged. The horizontal center axis of the sleeve is upwardly connected to the catch rod. By extending the catch head of the catch rod into the cavity in the flange seat 104, the plunger 2 is prevented from moving downward, thereby playing the role of capturing the plunger 2; by withdrawing the catch head of the catch rod from the cavity in the flange seat 104, the plunger 2 is released and the plunger 2 is released. The structure is simple and it is convenient to capture and release the plunger 2.

[0044] Specifically, the catcher 114 and the flange seat 104 are connected by a set screw 115. The stability of the connected structure is improved, the structure is simple, and the installation and disassembly are convenient.

[0045] Preferably, the simple wellhead assembly 1 further includes a handle 112 , and the handle 112 is connected to the outer side of the upper end of the blowout preventer 108 .

[0046] The handle 112 is convenient for opening and closing the spray cap 108, and has a simple structure and is easy to operate.

[0047] Preferably, the simple wellhead assembly 1 further comprises a sealing ring 107 , and the sealing ring 107 is sleeved between the flange seat 104 and the blowout preventer 108 .

[0048] The sealing ring 107 improves the air tightness of the connection between the flange seat 104 and the spray cap 108 .

[0049] Preferably, the plunger gas lift wellhead device for water drainage and gas production further includes a retaining ring 106 , which is sleeved between the flange seat 104 and the blowout preventer 108 .

[0050] The retaining ring 106 plays the role of axial limiting to prevent axial movement between the flange seat 104 and the spray cap 108. Specifically, the flange seat 104 and the spray cap 108 are connected by a set screw 105 to improve the stability of the connection and facilitate installation and disassembly.

[0051] Embodiment 2:

[0052] Based on Example 1, a method for using a wellhead device for plunger gas lift drainage and gas production includes the following steps:

[0053] During gas production, after the control valve 8 is opened, the downhole pressure difference pushes the plunger 2 upward to the simple wellhead assembly 1 and contacts the impact block 109, and the buffer spring 101 prevents the plunger 2 from moving upward; the downhole liquid and gas are discharged to the outside of the well through the pipeline assembly 7, and the control valve 8 is closed after the pressure of the oil pipe 4 is reduced, and the plunger 2 moves downward to the upper end of the buffer positioner 5, and the plunger 2 stops moving; a cycle of plunger gas lift drainage gas production is completed, and the above actions are repeated after the formation pressure is restored to complete gas production;

[0054] When the plunger is released, the gas tree 3 is closed, the blowout preventer 108 is removed, the catcher 114 is opened, the plunger 2 is released, the blowout preventer 108 is installed, the gas tree 3 is opened, the catcher 114 releases the plunger 2, and the plunger 2 moves downward to the upper end of the buffer positioner 5, completing the plunger release.

[0055] Specifically, during gas production (normal working state): after the electric regulating valve is opened, under the action of the downhole pressure difference, the plunger 2 moves up to the simple wellhead assembly 1 and contacts the impact block 109. Under the action of the buffer spring 101, the movement of the plunger 2 tends to stop, and the downhole liquid and gas are discharged to the outside of the well through the high-pressure pipeline. After the oil pipe pressure is reduced, the electric regulating valve is closed; after closing the electric regulating valve, the plunger moves downward to the upper end of the buffer positioner 5 under the action of its own gravity, and the plunger 2 stops moving; the above is one cycle of plunger 2 gas lift drainage and gas production cycle, and the above actions are repeated after the formation pressure is restored.

[0056] Plunger 2 placement: close the axial valve in the gas tree, remove the blowout preventer 108, rotate the catcher 114 to extend its catch head to the maximum, place the plunger, install the blowout preventer and ensure that it is sealed reliably, open the axial valve in the gas tree, rotate the catcher 114 to retract its catch head, and plunger 2 moves downward to the upper end of the buffer positioner 5 under its own gravity. The plunger placement is completed, and the well can be opened for trial operation only after the installation inspection is qualified.

[0057] By changing the internal structure of the wellhead device, the present invention can realize the buffering, launching, sealing and blowout prevention functions of the plunger 2 after reaching the wellhead, thereby reducing the manufacturing difficulty of the blowout preventer assembly, reducing the production cycle and workload, and improving production efficiency without reducing functions or performance.

[0058] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by terms such as "front", "inside", "right", etc. is based on the orientation or positional relationship shown in the drawings, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, the terms describing the positional relationship in the drawings are only used for illustrative purposes and cannot be understood as a limitation on the present invention.

[0059] The above examples are merely illustrative of the present invention and do not constitute a limitation on the protection scope of the present invention. All designs that are the same or similar to the present invention fall within the protection scope of the present invention.

Claims

1. A wellhead device for plunger gas lift water drainage and gas production, comprising a plunger (2), a gas tree (3), an oil pipe (4), a pressure transmitter (6), a pipeline assembly (7) and a control valve (8), characterized in that: The invention also comprises a simple wellhead assembly (1) and a buffer positioner (5), wherein the buffer positioner (5) is connected to an oil pipe (4), a plunger (2) is located in the oil pipe (4) above the buffer positioner (5), the oil pipe (4) on the buffer positioner (5) is connected to a gas production tree (3), the oil pipe (4) above the gas production tree (3) is connected to the simple wellhead assembly (1), the side of the gas production tree (3) is connected to a pipeline assembly (7), and the pipeline assembly (7) is connected to a pressure transmitter (6) and a control valve (8).

2. The plunger gas lift wellhead device for water drainage and gas production according to claim 1, characterized in that: The simple wellhead assembly (1) comprises a buffer spring (101) and a blowout preventer (108), wherein the buffer spring (101) is connected to the blowout preventer (108), the lower part of the blowout preventer (108) is internally connected to an oil pipe (4), and the lower part of the blowout preventer (108) is externally connected to a gas production tree (3).

3. The plunger gas lift wellhead device for water drainage and gas production according to claim 2, characterized in that: The simple wellhead assembly (1) further comprises a striking block (109), wherein the striking block (109) is connected to the lower end of the buffer spring (101).

4. The plunger gas lift wellhead device for water drainage and gas production as claimed in claim 3, characterized in that: The simple wellhead assembly (1) further comprises a flange seat (104), the upper end of the flange seat (104) is connected to a striker block (109), the upper part of the flange seat (104) is sleeved in the lower part of a blowout preventer (108), and the lower end of the flange seat (104) is connected to a gas production tree (3) on the outer side.

5. The plunger gas lift wellhead device for water drainage and gas production as claimed in claim 4, characterized in that: The simple wellhead assembly (1) further comprises a locking ring (110), and the lower end of the buffer spring (101) is connected to the impact block (109) via the locking ring (110).

6. The plunger gas lift wellhead device for water drainage and gas production as claimed in claim 5, characterized in that: The simple wellhead assembly (1) further comprises a catcher (114), the catcher (114) being connected to the side of the flange seat (104), and the catcher (114) being located below the blowout preventer (108).

7. The wellhead device for water drainage and gas production by plunger gas lift according to claim 6, characterized in that: The simple wellhead assembly (1) further comprises a handle (112), and the handle (112) is connected to the outer side of the upper end of the blowout preventer (108).

8. The plunger gas lift wellhead device for water drainage and gas production as claimed in claim 7, characterized in that: The simple wellhead assembly (1) further comprises a sealing ring (107), and the sealing ring (107) is sleeved between the flange seat (104) and the spray-proof cap (108).

9. The wellhead device for water drainage and gas production by plunger gas lift according to claim 8, characterized in that: The plunger gas lift wellhead device for water drainage and gas production also includes a retaining ring (106), which is sleeved between the flange seat (104) and the blowout preventer (108).

10. The method for using the wellhead device for water drainage and gas production by plunger gas lift according to claim 8, characterized in that: The steps include: During gas extraction, after the control valve (8) is opened, the downhole pressure difference pushes the plunger (2) upward to the simple wellhead assembly (1) and contacts the impact block (109), and the buffer spring (101) prevents the plunger (2) from moving upward; the downhole liquid and gas are discharged to the outside of the well through the pipeline assembly (7), and after the pressure of the oil pipe (4) is reduced, the control valve (8) is closed, and the plunger (2) moves downward to the upper end of the buffer positioner (5), and the plunger (2) stops moving; a cycle of plunger gas lift drainage gas extraction is completed, and the above-mentioned action is repeated after the formation pressure is restored to complete gas extraction; When the plunger is deployed, the gas tree (3) is closed, the spray cap (108) is removed, the catcher (114) is opened, the plunger (2) is deployed, the catcher (114) catches the plunger (2), the spray cap (108) is installed, the gas tree (3) is opened, the catcher (114) releases the plunger (2), and the plunger (2) moves downward to the upper end of the buffer positioner (5), completing the plunger deployment.

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