Oil well non-contact casing gas recovery device and method

Abstract

The invention discloses an oil well non-contact casing gas recovery device and belongs to the technical field of oil production engineering. Comprising a gas compression pressurizing device, a pressure regulator, a Christmas tree and a connecting pipeline, a gas compression pressurizing device compresses air, the compressed air passes through a high-pressure gas outlet and a high-pressure gas inlet of a pressure regulator through a pipeline I to drive the pressure regulator to work, a casing gas inlet of the pressure regulator is connected with a wellhead casing gas outlet of a Christmas tree through a pipeline II, and oil well shaft casing gas is pumped and pressurized through the pressure regulator. And through a casing gas outlet of the pressure regulator, the casing gas outlet is connected with a wellhead casing gas inlet trunk interface of the Christmas tree through a pipeline III, and the casing gas is recycled and enters a trunk line. In the pressurization and suction process, the time controller and the pressure controller are used for controlling start and stop of the compressor to control the pressure regulator to work. The non-contact working mode of electrical equipment and suction equipment is achieved when casing gas is recycled in an oil field, the anti-explosion grade is reduced, and safe production of the oil field is guaranteed.

Description

Technical Field

[0001] This invention belongs to the field of oilfield production engineering technology, specifically a non-contact casing gas recovery device and method for oil wells. Background Technology

[0002] Currently, as oilfield development deepens and formation energy decreases, gases originally dissolved in crude oil gradually precipitate out. With decreasing pressure, the amount of precipitated gas increases, accumulating between the tubing and casing in the wellbore – a phenomenon known as casing gas. This precipitated gas causes a decrease in pump efficiency during oil production, and in severe cases, pump gas locks the well, preventing oil production. This is particularly problematic for heavy oil wells, where casing gas affects the injection of fluids from the casing to the pump. Whether through hot washing, chemical dosing, or water injection under the pump, the presence of casing gas prevents the pressure from being reduced to zero. Furthermore, the increased pressure from accumulated casing gas significantly damages the chemical dosing pump. Due to pressure resistance, the pump operates under high load, leading to rapid plunger wear, high failure rate, and short service life. Another issue arises when the well requires water injection into the pump barrel; the presence of casing pressure causes large fluctuations in the water injection volume, preventing normal production. On-site, to address the issue of high casing pressure caused by increased casing gas, a method of balancing casing and mains pressure is generally adopted for recovery. However, this method is affected by the mains pressure; high mains pressure results in high casing pressure, and low mains pressure results in low casing pressure. It cannot provide stable casing pressure, and its effect is not significant for wells that require pump-assisted chemical and water injection. In order to reduce casing pressure, management has adopted methods such as increasing the power of the chemical injection machine and increasing the water injection pressure. However, since this cannot fundamentally solve the casing pressure problem, it not only increases costs but also has little effect.

[0003] The following comparison was made with existing patent technologies based on the search results: Comparison document 1 This invention relates to a device and method for recovering and sampling casing gas in oil wells (application number 202111294532.7). It includes a dewatering tank, a pressure gauge, a shut-off valve, a gas collecting pipe, a check valve I, a control valve, a tee joint, a sampling valve, and a sampling elbow. The dewatering tank is connected to the casing gate valve and the pressure gauge. Both ends of the gas collecting pipe are connected to the dewatering tank and one end of the check valve I, respectively. The other end of the check valve I is connected to the tee joint. The tee joint is connected to one end of the control valve and one end of the sampling valve, respectively. The other end of the control valve is connected to the return oil pipeline. The other end of the sampling valve is connected to one end of the sampling elbow. While this invention solves the dual production problems of casing gas recovery and sampling to prevent freezing and blockage, and prevents casing gas from polluting the external environment, its simple structure makes pressure difficult to control and operation inconvenient.

[0004] Comparison document 2 A casing gas recovery device for oil wells, application number 201410762610.5, includes: a power unit, a primary single-screw compressor pump, a connecting device, and a secondary single-screw pump connected in sequence. The connection between the power unit and the primary single-screw compressor pump has an intake chamber, with an intake pipe installed above and communicating with the intake chamber. The tail end of the secondary single-screw pump has a discharge chamber, with a discharge pipe installed above and communicating with the discharge chamber. One end of a lubricant return flow limiting pipe is connected to the lower part of the intake chamber, and the other end is connected to the lower part of a lubricant return flow limiting valve. The upper part of the lubricant return flow limiting valve is connected to the lower part of the discharge chamber. The intake chamber is filled with lubricant. This invention collects casing gas through a secondary single-screw pump and directly compresses natural gas via a controlled motor, which poses certain safety risks.

[0005] Comparison document 3 A multi-parameter integrated oil well gas acquisition and casing gas recovery device (application number 201910177684.5) comprises a display screen, a back pressure sensor, a partition, a data transmission module, a left clamp head, an upper clamp head, a control microcontroller, a casing gas flow valve I, a casing pressure sensor, a casing gas pressure regulating valve, an oil turbine, a gas turbine, a housing, a generator control motor, a right clamp head, a stroke collector, a current collector, a battery, and a magnetic coupling. This invention centralizes the parameter acquisition sensors within the housing, displays the parameters on the screen, and utilizes multiple collectors for self-generation. This solves the problems of messy electrical wiring layout and difficult explosion-proof protection, replaces the easily damaged mechanical pressure gauges, and solves the throttling and cooling problem. Although this invention achieves constant-pressure gas recovery in casing through acquisition and analysis, enabling reasonable casing pressure and oil well dynamic fluid level control, its complex structure, high manufacturing difficulty, and high cost hinder its widespread application.

[0006] In summary, the aforementioned oil well casing gas recovery equipment suffers from high costs due to its explosion-proof rating, complex structure, difficult manufacturing, and high price, and also poses certain safety risks. Therefore, a satisfactory solution to the problem of oil well casing gas recovery remains elusive. Summary of the Invention

[0007] To address the problems existing in the prior art, this invention provides a non-contact casing gas recovery device and method for oil wells. This invention has good explosion-proof performance and recovers clean casing gas. It is not only suitable for casing gas recovery in remote oilfield wells, single-well oil-pulling wells in elevated tanks, and wells with insufficient fluid supply, but also for cluster well groups, solving the problem of unsatisfactory casing gas recovery effect or high recovery cost in oilfields.

[0008] The technical solution of this invention is implemented as follows: A non-contact casing gas recovery device for oil wells includes: a gas compression and pressurization device, a pressure regulating section, a Christmas tree, pipeline I, pipeline II, pipeline III, check valve II, and check valve III; characterized in that: the gas compression and pressurization device compresses air, and the compressed air passes through the high-pressure gas outlet and through pipeline I to the high-pressure gas inlet of the pressure regulator to drive the pressure regulator to work; the casing gas inlet of the pressure regulator is connected to the casing gas outlet at the wellhead of the Christmas tree through pipeline II to draw in casing gas from the oil well, pressurizes it through the pressure regulator, and passes through the casing gas outlet of the pressure regulator; the casing gas outlet is connected to the casing gas inlet at the wellhead of the Christmas tree through pipeline III to recover the casing gas into the main pipeline.

[0009] As a preferred embodiment of the present invention, the gas compression and pressurization device is located near the electrical components of the oil well pumping equipment, and the gas compression and pressurization device is powered by the oil well power supply system.

[0010] As a preferred embodiment of the present invention, the gas compression and pressurization device comprises a control section and a compression and pressurization section, wherein the control section and the compression and pressurization section are installed in a skid-mounted gas compression and pressurization device.

[0011] As a preferred embodiment of the present invention, the high-pressure gas outlet of the pressure regulator is provided with a check valve I, and the installation of check valve I at the high-pressure gas outlet is a pressure-free setting.

[0012] As a preferred embodiment of the present invention, the pressure sensor of the pressure regulator is connected to the pressure controller of the control section via a signal line.

[0013] As a preferred embodiment of the present invention, the housing of the pressure regulator is fitted with a door, and the door is hinged to the housing.

[0014] As a preferred embodiment of the present invention, a one-way valve II is provided between the pipeline II and the wellhead casing gas outlet of the wellhead of the production tree.

[0015] As a preferred embodiment of the present invention, a one-way valve III is provided between the pipeline III and the wellhead casing gas inlet of the wellhead of the production tree.

[0016] As a preferred embodiment of the present invention, the control section includes an adjustment control box and a terminal box, wherein the adjustment control box and the terminal box are arranged vertically.

[0017] As a preferred embodiment of the present invention, the control section includes a start / stop button, a time controller, and a pressure controller, all of which are installed inside the control section's housing.

[0018] In a preferred embodiment of the present invention, the start / stop button of the control section is wired to the terminal box to control the motor circuit, and the start / stop button controls the start and stop of the motor.

[0019] As a preferred embodiment of the present invention, the compression and pressurization section consists of a control motor and a compressor, both of which are installed in a skid-mounted gas compression and pressurization device.

[0020] In a preferred embodiment of the present invention, the control unit is equipped with two control box doors arranged vertically, and the two control box doors are connected by hinges.

[0021] As a preferred embodiment of the present invention, the compression and pressurization section is equipped with four grille doors in the skid, and the grille doors are connected to the skid body by hinges.

[0022] In a preferred embodiment of the present invention, the time controller is connected to the start / stop button, and the time controller controls the running time of the motor.

[0023] In a preferred embodiment of the present invention, the pressure controller is connected to the pressure sensor via a signal line. The pressure sensor collects the inlet pressure of the casing gas and, in conjunction with the time controller, controls the start and stop of the motor.

[0024] In a preferred embodiment of the present invention, the control motor circuit is connected to the terminal box, and the control motor is equipped with a V-belt pulley I.

[0025] In a preferred embodiment of the present invention, the compressor and the control motor work together to compress and pressurize air, and the compressor is equipped with a V-belt pulley II which is connected to the control motor V-belt pulley I via a V-belt.

[0026] To ensure safe production in oilfields, the gas compression and pressurization section of the aforementioned non-contact casing gas recovery device for oil wells is kept at least 10 meters away from the wellhead tree.

[0027] As a method for non-contact casing gas recovery in oil wells according to the present invention, the method includes the following steps: Step 1. Set the time controller to start and stop the motor interval, and then set the pressure controller to start and stop the suction motor, controlling the maximum and minimum pressure. Step 2. Open the wellhead production tree control valve, press the start / stop button to start the control motor, the control motor drives the compressor to work through the V-belt, the compressor compresses and pressurizes the air through the high-pressure hose to the high-pressure gas inlet of the pressure regulator, the high-pressure gas drives the pressure regulator to pressurize the casing gas that has passed through the casing gas outlet and casing gas inlet of the wellhead, and then enters the trunk line through the casing gas outlet and the casing gas inlet of the wellhead. Step 3. After running for a period of time, based on the oil well production status and real-time pressure monitoring by the pressure sensor, adjust the pressure controller to determine the pump stop pressure and start pressure during suction. At the same time, based on the gas volume in the oil well casing, determine the start and stop interval of the control motor by setting the time controller. The optimal start and stop control motor time is determined by the cooperation of the pressure controller and the time controller.

[0028] As a preferred embodiment of the present invention, a gas compression and pressurization device of a non-contact casing gas recovery device for oil wells is used to control multiple pressure regulators. At the same time, multiple pressure controllers and time controllers need to be configured and work together to realize casing gas recovery for multiple oil wells in a well group. Compared with the prior art, the present invention has the following advantages:

[0029] 1. This invention controls the oil well casing pressure to the required pressure by controlling the compressor driven by the motor, and recovers and pressurizes the gas in the oil well casing for delivery. The outlet pressure is high. Because the power unit and the pressure regulator are isolated, the explosion-proof level of the equipment is reduced, the explosion-proof performance is good, and the cost is reduced.

[0030] 2. The driving gas of the pressure regulator used in this invention does not mix with the casing gas during operation, ensuring the cleanliness of the recovered casing gas.

[0031] 3. This invention rationally controls the start-up and shutdown times based on the amount of gas produced by the oil well. It is not only suitable for casing gas recovery in remote oilfield wells, single-well oil extraction wells in elevated tanks, and wells with insufficient fluid supply, but also for cluster well groups, where one compressor can simultaneously control the pressure regulators of multiple oil wells, thus achieving rational resource allocation.

[0032] 4. This invention controls the minimum suction pressure by setting a pressure controller, and by setting a time controller in conjunction with the pressure controller, it can reasonably extract casing gas, avoiding unlimited extraction of casing gas, which would cause negative pressure and damage to well equipment and facilities.

[0033] 5. This invention can record the casing gas pressure in a timely manner by setting a pressure sensor.

[0034] 6. This invention increases ventilation and heat exchange by setting up a grille door. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the overall structure of the present invention. In the diagram: 1. Gas compression and pressurization device; 1-1. Control section; 1-2. Adjustment control box; 1-2-1. Control box door; 1-2-2. Start / stop button; 1-2-3. Time controller; 1-2-4. Pressure controller; 1-2-5. Terminal box; 1-3. Compression and pressurization section; 1-3-1. Control motor; 1-3-2. V-belt pulley I; 1-3-3. Compressor; 1-3-4. V-belt pulley II; 1-3-5. High-pressure gas outlet; 1-3-6. Three 1. Angle belt, 1-3-7. Grille door; 2. Pressure regulating section, 2-1. Outer shell, 2-2. Door, 2-3. Pressure regulator, 2-4. Casing gas inlet, 2-5. Casing gas outlet, 2-6. High-pressure gas outlet, 2-7. High-pressure gas inlet, 2-8. Pressure sensor, 2-9. Check valve I; 3. Wellhead, 3-1. Wellhead casing gas inlet, 3-2. Wellhead casing gas outlet; 4. Pipeline I; 5. Pipeline II; 6. Pipeline III; 7. Check valve II; 8. Check valve III. Detailed Implementation

[0036] To further understand the invention's content, features, and effects, the following embodiments are described in detail with reference to the accompanying drawings.

[0037] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings. Example 1

[0038] like Figure 1 As shown, the present invention discloses a non-contact casing gas recovery device for oil wells, comprising: a gas compression and pressurization device 1, a pressure regulating section 2, a treehouse 3, pipeline I 4, pipeline II 5, pipeline III 6, check valve II 7, and check valve III 8; characterized in that: the gas compression and pressurization device 1 compresses air, and the compressed air passes through the high-pressure gas outlet 1-3-5 and through pipeline I 4 to the high-pressure gas inlet 2-7 of the pressure regulating section 2 to drive the pressure regulating section 2 to work; the casing gas inlet 2-4 of the pressure regulating section 2 is connected to the wellhead casing gas outlet 3-2 of the treehouse 3 through pipeline II 5 to draw in the casing gas from the oil well, pressurizes it through the pressure regulating section 2, and passes through the casing gas outlet 2-5 of the pressure regulating section 2; the casing gas outlet 2-5 is connected to the wellhead casing gas inlet 3-1 of the treehouse 3 through pipeline III 6 to recover the casing gas into the main pipeline.

[0039] Specifically, the gas compression and pressurization device 1 is located near the electrical components of the oil well pumping equipment, and the gas compression and pressurization device 1 is powered by the oil well power supply system.

[0040] Specifically, the gas compression and pressurization device 1 consists of a control part 1-1 and a compression and pressurization part 1-3, which are installed in a skid-mounted gas compression and pressurization device 1.

[0041] Specifically, the pressure regulating section 2 has a check valve I2-9 installed at the high-pressure gas outlet 2-6, and the check valve I2-9 installed at the high-pressure gas outlet 2-6 is a pressure-free setting.

[0042] Specifically, the pressure sensor 2-8 of the pressure regulating part 2 is connected to the pressure controller 1-2-4 of the control part 1-1 via a signal line.

[0043] Specifically, a door 2-2 is installed on the outer shell 2-1 of the pressure regulating part 2, and the door 2-2 is hinged to the outer shell 2-1.

[0044] Specifically, a one-way valve II7 is provided between the pipeline II5 and the wellhead casing gas outlet 3-2 of the wellhead of the production tree 3 to prevent natural gas backflow.

[0045] Specifically, a one-way valve III8 is provided between the pipeline III6 and the wellhead casing gas inlet 3-1 of the wellhead of the production tree 3 to prevent the produced fluid from flowing back into the pressure regulating section 2.

[0046] Specifically, the control section 1-1 includes an adjustment control box 1-2 and a terminal box 1-2-5, which are arranged vertically.

[0047] Specifically, the control unit 1-1 includes a start / stop button 1-2-2, a time controller 1-2-3, and a pressure controller 1-2-4, all of which are installed inside the housing of the control unit 1-1.

[0048] Specifically, the start / stop button 1-2-2 of the control section 1-1 is connected to the terminal box 1-2-5 to control the circuit of motor 1-3-1, and the start / stop button 1-2-2 controls the start and stop of motor 1-3-1.

[0049] Specifically, the compression and pressurization section 1-3 consists of a control motor 1-3-1 and a compressor 1-3-3. Both the control motor 1-3-1 and the compressor 1-3-3 are installed inside the skid-mounted gas compression and pressurization device 1, which facilitates skid-mounted transportation.

[0050] Specifically, the control unit 1-1 is equipped with two control box doors 1-2-1, which are arranged vertically and connected by hinges.

[0051] Specifically, the compression and pressurization part 1-3 has four grille doors 1-3-7 installed in the skid, and the grille doors 1-3-7 are connected to the skid body by hinges.

[0052] Specifically, the time controller 1-2-3 is connected to the start / stop button 1-2-2, and the time controller 1-2-3 controls the running time of the motor 1-3-1.

[0053] Specifically, the pressure controller 1-2-4 is connected to the pressure sensor 2-8 via a signal line. The pressure sensor 2-8 collects the inlet pressure of the casing gas and works in conjunction with the time controller 1-2-3. The pressure controller 1-2-4 controls the start and stop of the motor 1-3-1.

[0054] The above solution avoids the ineffective operation of pressure controllers 1-2-4 and pressure regulators 2-3 caused by motor 1-3-1 running for extended periods, and also extends their service life.

[0055] Specifically, the control motor 1-3-1 circuit is connected to the terminal box 1-2-5, and the control motor 1-3-1 is equipped with a V-belt pulley I1-3-2.

[0056] Specifically, the compressor 1-3-3 works in conjunction with the control motor 1-3-1 to compress and pressurize air. The compressor 1-3-3 is equipped with a V-belt pulley II 1-3-4, which is connected to the control motor 1-3-1 via a V-belt I 1-3-2.

[0057] By setting up a 1-3-6 V-belt drive, the power transmission efficiency is improved. Example 2 1. An installation method for a non-contact casing gas recovery device for oil wells:

[0058] First, a gas compression and pressurization device 1 of a non-contact casing gas recovery device for oil wells is installed next to the electrical control cabinet of the pumping equipment, at a distance of more than 10m from the wellhead tree. Second, connect the power supply from the oil pumping equipment control cabinet to the terminal box 1-2-5, and connect the high-pressure gas outlet 1-3-5 of the compression and pressurization section 1-3 to the high-pressure gas inlet 2-7 of the pressure regulator 2-3 using a high-pressure hose. Third, connect the pressure controller 1-2-4 and the pressure sensor 2-8 using a data acquisition cable; Fourth, use a high-pressure hose to connect the wellhead casing gas outlet 3-2 to the casing gas inlet 2-4, and finally use a high-pressure hose to connect the casing gas outlet 2-5 to the wellhead casing gas inlet 3-1. 2. A non-contact casing gas recovery method for oil wells:

[0059] Step 1. Set the time interval for starting and stopping the control motor 1-3-1 of the time controller 1-2-3 in the regulating control box 1-2 of this invention, and then set the maximum and minimum pressure of the suction start and stop control motor 1-3-1 of the pressure controller 1-2-4; Step 2. Open the wellhead production tree 3 control valve, press the start / stop button 1-2-2 to start the control motor 1-3-1. The control motor 1-3-1 drives the compressor 1-3-3 through the V-belt 1-3-6. The compressor 1-3-3 compresses and pressurizes the air, which reaches the high-pressure air inlet 2-7 of the pressure regulator 2-3 through the high-pressure hose. The high-pressure air drives the pressure regulator 2-3 to pressurize the casing air that has passed through the wellhead casing air outlet 3-2 and casing air inlet 2-4, and then enters the main line through the casing air outlet 2-5 and the wellhead casing air inlet 3-1. Step 3. After the invention has been running for a period of time, based on the oil well production status and the real-time pressure monitoring of pressure sensor 2-8, the pressure controller 1-2-4 is adjusted to determine the pump stop pressure and start pressure during suction. At the same time, based on the gas volume in the oil well casing, the start and stop interval of control motor 1-3-1 is determined by setting time controller 1-2-3. Through the cooperation of pressure controller 1-2-4 and time controller 1-2-3, the optimal start and stop time of control motor 1-3-1 is determined. Example 3

[0060] The present invention discloses a non-contact casing gas recovery device for oil wells. Its gas compression and pressurization device 1 compresses air. The compressed air passes through a high-pressure gas outlet 1-3-5 and is connected via pipeline I4 to the high-pressure gas inlet 2-7 of a pressure regulating section 2, driving the pressure regulating section 2 to operate. The casing gas inlet 2-4 of the pressure regulating section 2 is connected via pipeline II5 to the wellhead casing gas outlet 3-2 of the wellhead of the Christmas tree 3, drawing in casing gas from the oil well. After being pressurized by the pressure regulating section 2, the gas passes through the casing gas outlet 2-5 of the pressure regulating section 2. The casing gas outlet 2-5 is connected via pipeline III6 to the wellhead casing gas inlet 3-1 of the wellhead of the Christmas tree 3, recovering the casing gas and sending it into the main pipeline.

[0061] A non-contact casing gas recovery device for oil wells utilizes a gas compression and pressurization device 1 to control multiple pressure regulating parts 2. By configuring multiple pressure controllers 1-2-4 and time controllers 1-2-3 to work in coordination, casing gas recovery can be achieved from multiple oil wells in a well group. This aims to improve the economic benefits of the oilfield.

[0062] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0063] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A non-contact casing gas recovery device for oil wells, comprising: Gas compression and pressurization device (1), pressure regulation section (2), wellhead (3), pipeline I (4), pipeline II (5), pipeline III (6), check valve II (7), check valve III (8); characterized in that: the gas compression and pressurization device (1) compresses air, the compressed air passes through the high pressure gas outlet (1-3-5) and through pipeline I (4) to drive the pressure regulation section (2) to work, the casing gas inlet (2-4) of the pressure regulation section (2) is connected to the wellhead casing gas outlet (3-2) of the wellhead (3) through pipeline II (5), the casing gas inlet (2-4) of the pressure regulation section (2) is pressurized, and through the casing gas outlet (2-5) of the pressure regulation section (2), the casing gas outlet (2-5) is connected to the wellhead casing gas inlet (3-1) of the wellhead (3) through pipeline III (6), and the casing gas is recovered and enters the trunk line.

2. The non-contact casing gas recovery device for oil wells according to claim 1, characterized in that: The gas compression and pressurization device (1) is located near the electrical components of the oil well pumping equipment, and the gas compression and pressurization device (1) is powered by the oil well power supply system.

3. The non-contact casing gas recovery device for oil wells according to claim 1, characterized in that: The gas compression and pressurization device (1) consists of a control part (1-1) and a compression and pressurization part (1-3), which are installed in a skid-mounted gas compression and pressurization device (1).

4. The non-contact casing gas recovery device for oil wells according to claim 1, characterized in that: The pressure regulating part (2) has a single-flow valve I (2-9) installed at the high-pressure gas outlet (2-6). The installation of the single-flow valve I (2-9) at the high-pressure gas outlet (2-6) is a pressure-free setting.

5. The non-contact casing gas recovery device for oil wells according to claim 1, characterized in that: The pressure sensor (2-8) of the pressure regulating part (2) and the pressure controller (1-2-4) of the control part (1-1) are connected by a signal line.

6. The non-contact casing gas recovery device for oil wells according to claim 1, characterized in that: The pressure regulating part (2) has a door (2-2) mounted on its outer casing (2-1), and the door (2-2) is hinged to the outer casing (2-1).

7. The non-contact casing gas recovery device for oil wells according to claim 1, characterized in that: A single-flow valve II (7) is provided between the pipeline II (5) and the wellhead casing gas outlet (3-2) of the tree (3).

8. The non-contact casing gas recovery device for oil wells according to claim 1, characterized in that: A single-flow valve III (8) is provided between the pipeline III (6) and the wellhead casing gas inlet (3-1) of the wellhead of the tree (3).

9. The non-contact casing gas recovery device for oil wells according to claim 3, characterized in that: The control unit (1-1) includes an adjustment control box (1-2) and a terminal box (1-2-5), which are arranged vertically.

10. A non-contact casing gas recovery device for oil wells according to claim 3, characterized in that: The control unit (1-1) includes a start / stop button (1-2-2), a time controller (1-2-3), and a pressure controller (1-2-4). The start / stop button (1-2-2), the time controller (1-2-3), and the pressure controller (1-2-4) are all installed inside the box of the control unit (1-1).

11. The non-contact casing gas recovery device for oil wells according to claim 3, characterized in that: The start / stop button (1-2-2) of the control section (1-1) is connected to the terminal box (1-2-5) to control the motor (1-3-1) circuit. The start / stop button (1-2-2) controls the start and stop of the motor (1-3-1).

12. The non-contact casing gas recovery device for oil wells according to claim 3, characterized in that: The compression and pressurization section (1-3) consists of a control motor (1-3-1) and a compressor (1-3-3), both of which are installed inside the skid-mounted gas compression and pressurization device (1).

13. The non-contact casing gas recovery device for oil wells according to claim 3, characterized in that: The control unit (1-1) is equipped with two control box doors (1-2-1), which are arranged vertically and connected by hinges.

14. The non-contact casing gas recovery device for oil wells according to claim 3, characterized in that: The compression and pressurization section (1-3) has four grille doors (1-3-7) installed in the skid, and the grille doors (1-3-7) are connected to the skid body by hinges.

15. The non-contact casing gas recovery device for oil wells according to claim 10, characterized in that: The time controller (1-2-3) is connected to the start / stop button (1-2-2), and the time controller (1-2-3) controls the running time of the motor (1-3-1).

16. The non-contact casing gas recovery device for oil wells according to claim 10, characterized in that: The pressure controller (1-2-4) is connected to the pressure sensor (2-8) via a signal line. The pressure sensor (2-8) collects the inlet pressure of the casing gas and works in conjunction with the time controller (1-2-3). The pressure controller (1-2-4) controls the motor (1-3-1) to start and stop.

17. A non-contact casing gas recovery device for oil wells according to claims 1-1, characterized in that: The control motor (1-3-1) circuit is connected to the terminal box (1-2-5), and the control motor (1-3-1) is equipped with a V-belt pulley I (1-3-2).

18. A non-contact casing gas recovery device for oil wells according to claims 1-2, characterized in that: The compressor (1-3-3) and the control motor (1-3-1) work together to compress and pressurize air. The compressor (1-3-3) is equipped with a V-belt pulley II (1-3-4) and the control motor (1-3-1) and V-belt pulley I (1-3-2) are connected together by a V-belt (1-3-6).

19. A non-contact casing gas recovery method for oil wells, comprising the following steps: Step 1. Set the time interval for the start and stop of the motor (1-3-1) of the time controller (1-2-3) of the regulating control box (1-2), and then set the maximum and minimum pressure of the suction start and stop motor (1-3-1) of the pressure controller (1-2-4). Step 2. Open the wellhead production tree (3) control valve, press the start / stop button (1-2-2) to start the control motor (1-3-1), the control motor (1-3-1) drives the compressor (1-3-3) through the V-belt (1-3-6), the compressor (1-3-3) compresses and pressurizes the air through the high pressure hose to the high pressure gas inlet (2-7) of the pressure regulator (2-3), the high pressure gas drives the pressure regulator (2-3) to pressurize the casing gas passing through the wellhead casing gas outlet (3-2) and casing gas inlet (2-4), and then enter the trunk line through the casing gas outlet (2-5) and the wellhead casing gas inlet (3-1); Step 3. After running for a period of time, based on the oil well production status and the real-time pressure monitoring of the pressure sensor (2-8), adjust the pressure controller (1-2-4) to determine the pump stop pressure and start pressure during suction. At the same time, based on the gas volume of the oil well casing, determine the start and stop interval of the control motor (1-3-1) by setting the time controller (1-2-3). Through the cooperation of the pressure controller (1-2-4) and the time controller (1-2-3), determine the optimal start and stop time of the control motor (1-3-1).

20. A non-contact casing gas recovery method for oil wells according to claim 19, characterized in that: A gas compression and pressurization device (1) of a non-contact casing gas recovery device for oil wells controls multiple pressure regulator parts (2), and multiple pressure controllers (1-2-4) and time controllers (1-2-3) need to be configured and work together to realize casing gas recovery for multiple oil wells in a well group.

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