Gas well suction and drainage system and method

Abstract

The present invention belongs to the technical field of petroleum fracturing, and specifically discloses a gas well suction and drainage system and method. It includes an oil pipe, a drainage system and a control system; the drainage system is arranged in the oil pipe, a check valve is arranged on the top of the drainage system, the outlet of the check valve is connected to the inlet of the energy chamber, a jet is arranged on the bottom of the drainage system, the exhaust port of the energy chamber is connected to the jet, the liquid level signal output end of the drainage system is connected to the signal input end of the control system, and the control signal output end of the control system is connected to the control signal input end of the drainage system. The present invention controls the drainage system to absorb liquid, and uses the liquid gasification as the rising kinetic energy to discharge the absorbed liquid out of the well, so as to efficiently remove the liquid in the well, increase the production, and reduce the accident rate.

Description

Technical Field

[0001] The invention belongs to the technical field of petroleum fracturing, and in particular relates to a gas well suction and drainage system and method. Background Art

[0002] For water-bearing reservoirs, after hydraulic fracturing, due to the large water production of some wells, which is higher than the critical liquid carrying rate of the gas well, a large amount of liquid in the wellbore cannot be discharged, and the natural gas production decreases. The existing nitrogen gas lift process is costly and has poor continuity, while the plunger drainage gas production process requires the target well to have a corresponding gas production to discharge the accumulated liquid in the wellbore. The early suction and drainage devices have well control risk problems such as wire rope winding.

[0003] Nitrogen gas lift costs 4,000 yuan per hour, and each well requires an average of 30 hours of gas lift, totaling 120,000 yuan, which is quite costly.

[0004] Nitrogen gas lift is mainly used when liquid accumulation is serious, and is not used throughout the drainage process. Therefore, the drainage is discontinuous, resulting in the inability to discharge the liquid in time, affecting production. Summary of the invention

[0005] The present invention provides a gas well suction and drainage system and method, so as to solve the technical problem that it is difficult to drain the gas well, resulting in safety accidents and reduced gas well production.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0007] In a first aspect, a gas well pumping and drainage system includes an oil pipe, a drainage system and a control system;

[0008] The drainage system is arranged in the oil pipe, a check valve is provided on the top of the drainage system, the outlet of the check valve is connected to the inlet of the energy chamber, a jet port is provided at the bottom of the drainage system, the exhaust port of the energy chamber is connected to the jet port, a liquid level signal acquisition device is arranged in the drainage system, a signal output end of the liquid level signal acquisition device is connected to the control system, and a control signal output end of the control system is connected to a control signal input end of the drainage system.

[0009] A further improvement of the present invention is that the oil pipe is vertically arranged on the ground, an inner oil pipe higher than the oil pipe is arranged on the outside of the oil pipe, casings are arranged on both sides of the lower part of the inner oil pipe, oil pipe outlets are arranged on both sides of the upper part of the inner oil pipe, a charging pile is arranged on the top of the inner oil pipe, and a main control room is arranged above the charging pile.

[0010] A further improvement of the present invention is that a rechargeable battery is connected to the power input end of the drainage system.

[0011] A further improvement of the present invention is that two normally closed sleeve valves are provided on each side of the sleeve, namely a first sleeve valve, a second sleeve valve, a third sleeve valve and a fourth sleeve valve.

[0012] A further improvement of the present invention is that two oil pipe outlet valves are arranged on each side of the oil pipe outlet, the first oil pipe outlet valve and the second oil pipe outlet valve are close to the inner oil pipe, and the third oil pipe outlet valve and the fourth oil pipe outlet valve are far from the inner oil pipe.

[0013] A further improvement of the present invention is that the two oil pipe outlets are respectively connected to the first liquid storage tank or the second liquid storage tank.

[0014] A further improvement of the present invention is that a drain / liquid inlet valve is provided in the inner oil pipe below the charging pile.

[0015] A further improvement of the present invention is that a first inner oil pipe valve is provided at the lower part of the inner oil pipe, and a second inner oil pipe valve is provided at the upper part, and the two inner oil pipe valves are between the casing and the oil pipe outlet.

[0016] A further improvement of the present invention is that the drainage system further comprises an air inlet and an air outlet, the air inlet is arranged at the top of the drainage system, and the air outlet is arranged at the side of the drainage system.

[0017] In a second aspect, a gas well pumping and drainage method comprises the following steps:

[0018] The drainage system enters the preset position of the oil pipe;

[0019] When the liquid level reaches the preset line of the drainage system, the control system controls the drainage system to open the check valve and suck part of the liquid into the energy chamber. The liquid is gasified and ejected from the jet port, so that the drainage system rises to the oil pipe outlet and discharges excess liquid to the liquid storage tank. Then the drainage system rises to the charging pile to start charging.

[0020] The drainage system that has completed charging opens the air inlet and outlet to discharge excess gas, and repeats the above steps until all the accumulated liquid in the well is drained.

[0021] Compared with the prior art, the present invention has at least the following beneficial effects:

[0022] The present invention controls the liquid drainage system to absorb liquid, and uses the liquid gasification as rising kinetic energy to discharge the absorbed liquid out of the well, thereby efficiently removing the liquid in the well, increasing the production and reducing the accident rate.

[0023] The present invention provides a charging pile and a charging battery for the drainage system, so that the drainage system can be circulated and used more conveniently.

[0024] The present invention provides an air inlet and an air outlet for the liquid discharge system, and after the liquid discharge system rises, the excess gas is discharged, so that the liquid discharge system can be circulated. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0026] Figure 1 An overall schematic diagram of a gas well pumping and drainage system of the present invention;

[0027] Figure 2 A schematic structural diagram of a drainage system of a gas well suction and drainage system of the present invention.

[0028] In the figure: 1. first inner oil pipe valve; 2. first casing valve; 3. second casing valve; 4. second inner oil pipe valve; 5. third casing valve; 6. fourth casing valve; 7. venting / liquid inlet valve; 8. first oil pipe outlet valve; 9. second oil pipe outlet valve; 10. third oil pipe outlet valve; 11. fourth oil pipe outlet valve; 12. charging pile; 13. main control room; 14. drainage system; 15. first liquid storage tank; 16. second liquid storage tank; 17. ground; 18. oil pipe; 19. oil pipe outlet; 20. inner oil pipe; 21. casing; 100. check valve; 101. energy chamber; 102. air outlet; 103. air inlet; 104. rechargeable battery; 105. jet nozzle. DETAILED DESCRIPTION

[0029] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other without conflict.

[0030] The following detailed description is an exemplary description, which is intended to provide further detailed description of the present invention. Unless otherwise specified, all technical terms used in the present invention have the same meaning as those generally understood by those skilled in the art to which the present invention belongs. The terms used in the present invention are only for describing specific embodiments, and are not intended to limit the exemplary embodiments according to the present invention.

[0031] Example 1

[0032] like Figure 1 As shown, a gas well suction and drainage system includes an oil pipe 18, a drainage system 14 and a main control room 13;

[0033] The drainage system 14 is arranged in the oil pipe 18, and a check valve 100 is arranged on the top of the drainage system 14, and the outlet of the check valve 100 is connected to the inlet of the energy chamber 101. A jet port 105 is arranged at the bottom of the drainage system 14, and the exhaust port of the energy chamber 101 is connected to the jet port 105. A liquid level signal acquisition device is arranged in the drainage system 14, and the signal output end of the liquid level signal acquisition device is connected to the control system, and the control signal output end of the control system is connected to the control signal input end of the drainage system 14.

[0034] The oil pipe 18 is vertically arranged on the ground 17, and an inner oil pipe 20 higher than the oil pipe is arranged on the outside of the oil pipe 18, casings 21 are arranged on both sides of the lower part of the inner oil pipe 20, and oil pipe outlets 19 are arranged on both sides of the upper part of the inner oil pipe 20. A charging pile 12 is arranged on the top of the inner oil pipe 20, and a main control room 13 is arranged above the charging pile 12, and a control system is arranged in the main control room 13.

[0035] The drainage system 14 is used to enter the oil pipe 18 and absorb the liquid in the oil pipe through the one-way valve 100. The absorbed liquid enters the energy chamber 101 for vaporization. The vaporized airflow is discharged from the jet port 103 to make the drainage system 14 rise along the oil pipe 18. When the drainage system 14 reaches the charging pile 12, it charges the rechargeable battery 104. After charging is completed, the air outlet 102 and the air inlet 103 are opened to discharge excess gas, so that the drainage system 14 sinks along the oil pipe 18 again.

[0036] The power input end of the liquid discharge system 14 is connected to a rechargeable battery 104, which is used to supply power to the one-way valve 100, the energy chamber 101, the air outlet 102, the air inlet 103 and the jet 105, so that the one-way valve 100, the air outlet 102, the air inlet 103 and the jet 105 can be switched on and off with the control system; so that the temperature in the energy chamber 101 is sufficient to vaporize the liquid.

[0037] Two normally closed casing valves are provided on each side of the casing 21 , namely a first casing valve 2 , a second casing valve 3 , a third casing valve 5 and a fourth casing valve 6 .

[0038] Two oil pipe outlet valves are arranged on each side of the oil pipe outlet 19 , the first oil pipe outlet valve 8 and the second oil pipe outlet valve 9 are close to the inner oil pipe 20 , and the third oil pipe outlet valve 10 and the fourth oil pipe outlet valve 11 are far away from the inner oil pipe 20 .

[0039] The two oil pipe outlets 19 are connected to the first liquid storage tank 15 or the second liquid storage tank 16 respectively.

[0040] A drain / liquid inlet valve 7 is provided in the inner oil pipe 20 below the charging pile 12 .

[0041] A first inner oil pipe valve 1 is provided at the lower part of the inner oil pipe 20 , and a second inner oil pipe valve 4 is provided at the upper part. The two inner oil pipe valves are between the casing 21 and the oil pipe outlet 19 .

[0042] The drainage system 14 further includes an air inlet 103 and an air outlet 102 . The air inlet 103 is arranged at the top of the drainage system 14 , and the air outlet 102 is arranged at the side of the drainage system 14 .

[0043] Example 2

[0044] A gas well pumping and drainage method, based on the gas well pumping and drainage system described in Example 1, comprises the following steps:

[0045] Open the first inner oil pipe valve 1, the first oil pipe outlet valve 8, the second oil pipe outlet valve 9 and the venting / liquid inlet valve 7, close the second inner oil pipe valve 4, the third oil pipe outlet valve 10 and the fourth oil pipe outlet valve 11, release the pressure to a balanced state, and then the drainage system 14 sinks along the inner oil pipe to the preset position of the oil pipe 18;

[0046] Close the vent / liquid inlet valve 7, the air inlet 103 and the air outlet 102 of the drainage system 14, open the second inner oil pipe valve 4, and the drainage system 14 enters the oil pipe 18; open the third oil pipe outlet valve 10 and the fourth oil pipe outlet valve 11, close the air inlet 103 and the air outlet 102 of the drainage system 14, and the drainage system 14 starts to work;

[0047] When the liquid level of the drainage system 14 reaches the specified position, the main control room 13 controls the drainage system 14 to open the check valve 100 and suck part of the liquid into the energy chamber 101. The liquid is gasified and then ejected from the jet port 105, so that the drainage system 14 rises to the oil pipe outlet and discharges the excess liquid to the liquid storage tank. Then, the drainage system 14 rises to the charging pile 12 to start charging.

[0048] The liquid discharge system 14 that has completed charging opens the air inlet 103 and the air outlet 102 to discharge the excess gas, and repeats the above steps until the liquid accumulated in the well is completely discharged.

[0049] Applicable to unconventional water-producing reservoirs such as tight oil, tight gas and shale gas.

[0050] It is known from common technical knowledge that the present invention can be implemented by other embodiments that do not deviate from its spirit or essential features. Therefore, the above disclosed embodiments are only illustrative in all respects and are not exclusive. All changes within the scope of the present invention or within the scope equivalent to the present invention are included in the present invention.

[0051] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A gas well pumping and drainage method, based on a gas well pumping and drainage system, characterized in that: A gas well suction and drainage system, comprising an oil pipe (18), a drainage system (14) and a control system; The drainage system (14) is arranged in the oil pipe (18); a check valve (100) is arranged at the top of the drainage system (14); an outlet of the check valve (100) is connected to an inlet of an energy chamber (101); an air jet (105) is arranged at the bottom of the drainage system (14); an exhaust port of the energy chamber (101) is connected to the air jet (105); a liquid level signal acquisition device is arranged in the drainage system (14); a signal output end of the liquid level signal acquisition device is connected to a control system; and a control signal output end of the control system is connected to a control signal input end of the drainage system (14); The oil pipe (18) is vertically arranged on the ground (17); an inner oil pipe (20) higher than the oil pipe is arranged outside the oil pipe (18); casings (21) are arranged on both sides of the lower part of the inner oil pipe (20); oil pipe outlets (19) are arranged on both sides of the upper part of the inner oil pipe (20); a charging pile (12) is arranged on the top of the inner oil pipe (20); and a main control room (13) is arranged above the charging pile (12); Each side of the sleeve (21) is provided with two normally closed sleeve valves, namely a first sleeve valve (2), a second sleeve valve (3), a third sleeve valve (5) and a fourth sleeve valve (6); Two oil pipe outlet valves are provided on each side of the oil pipe outlet (19), the first oil pipe outlet valve (8) and the second oil pipe outlet valve (9) being close to the inner oil pipe (20), and the third oil pipe outlet valve (10) and the fourth oil pipe outlet valve (11) being far from the inner oil pipe (20); The inner oil pipe (20) is provided with a first inner oil pipe valve (1) at the lower part and a second inner oil pipe valve (4) at the upper part, the two inner oil pipe valves being located between the casing (21) and the oil pipe outlet (19); The drainage system (14) further comprises an air inlet (103) and an air outlet (102), wherein the air inlet (103) is arranged at the top of the drainage system (14), and the air outlet (102) is arranged at the side of the drainage system (14); Gas well pumping and drainage method, including: The drainage system (14) enters the oil pipe (18) at a preset position; When the liquid level reaches the preset line of the liquid discharge system (14), the control system controls the liquid discharge system (14) to open the check valve (100) and suck part of the liquid into the energy chamber (101). The liquid is then vaporized and ejected from the jet port (105), so that the liquid discharge system (14) rises to the oil pipe outlet (19) and discharges excess liquid to the liquid storage tank. Then, the liquid discharge system (14) rises to the charging pile (12) to start charging. The liquid discharge system (14) that has completed charging opens the air inlet (103) and the air outlet (102) to discharge excess gas, and the above steps are repeated until the liquid accumulated in the well is completely discharged.

2. A gas well pumping and drainage system according to claim 1, characterized in that: The power input end of the drainage system (14) is connected to a rechargeable battery (104).

3. A gas well pumping and drainage system according to claim 1, characterized in that: The two oil pipe outlets (19) are respectively connected to the first liquid storage tank (15) or the second liquid storage tank (16).

4. A gas well pumping and drainage system according to claim 1, characterized in that: A drain / liquid inlet valve (7) is provided in the inner oil pipe (20) below the charging pile (12).

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