An oil well oil and gas collection device

Abstract

An oil well oil and gas collection device includes a hydraulic reversing valve, a hydraulic cylinder with an oil cylinder tee and a on-off valve connected in sequence at both ends; two inlet and outlet pipes A and B are led out from the A port and B port of the hydraulic reversing valve and are respectively connected to the oil cylinder tee to push the piston in the hydraulic cylinder to move; the hydraulic reversing valve is provided with a P inlet port and a T drain port connected through a drain tee, and two P pressure guiding pipes are led out from the P inlet port and are respectively connected to the P ports of the on-off valves on both sides for liquid inlet; two T pressure guiding pipes are led out from the T drain port and are respectively connected to the T ports of the on-off valves on both sides for liquid drainage; one X pressure guiding pipe is respectively led out from the valve bottoms at both ends of the hydraulic reversing valve and is connected to the X port of the on-off valve on the same side for liquid inlet to push the spool of the reversing valve to move; one Y pressure guiding pipe is respectively led out from the valve bottom of each on-off valve and is connected to the Y port of the on-off valve on the other side to push the spool of the on-off valve to move; the A port and B port of the hydraulic reversing valve are alternately connected and communicated with the oil circuits of the P inlet port and the T drain port through the movement of its spool to change the inlet and outlet liquid directions. The present invention realizes the collection of oil well oil and gas.

Description

Technical Field

[0001] The present invention relates to the technical field of oilfield oil production, and particularly relates to an oil well casing gas recovery device. Specifically, it is an oil well oil and gas collection device. Background Art

[0002] During the oilfield production process, when the pressure of the oil well drops to the bubble point pressure, natural gas will be separated from the crude oil. Part of the separated natural gas is brought to the ground with the oil liquid, and the other part accumulates in the annular space of the oil well casing, forming casing pressure, which becomes the oil well casing gas. When the casing gas of the oil well accumulates to a certain pressure, the dynamic liquid level of the oil well will change, the dynamic liquid level will drop, and the liquid production of the oil well will decrease. In severe cases, gas locking will occur, and the gas locking phenomenon will cause the oil well to be unable to produce normally. In actual production and development, it is very difficult to utilize and recover the casing gas.

[0003] Usually, in the actual production operations of major oilfields, the gas recovery form of using a check valve to hold pressure and release gas is mostly adopted, and to a certain extent, part of the casing gas can also be recovered. However, there is an inevitable and fatal technical defect in this technology, that is, the long-term pressure holding of the casing gas directly affects the change of the submergence degree of the oil well, causes the dynamic liquid level of the oil well to drop, and reduces the normal production efficiency of the oil well.

[0004] Therefore, in some oil production operation areas of oilfields, there are phenomena of venting and ignition and burning, which cause air pollution, so it is urgent to solve. Summary of the Invention

[0005] The present invention provides an oil well oil and gas collection device, aiming to solve the technical problem that it is very difficult to utilize and recover the long-term pressure holding of the casing gas in actual production and development.

[0006] The technical solution of the present invention is as follows:

[0007] An oil well oil and gas collection device, including a hydraulic directional valve and a hydraulic cylinder; characterized in that both ends of the hydraulic cylinder 1 are respectively connected to the cylinder three-way 11, and both ends are connected to the on-off valve 12 through the cylinder three-way; two inlet and outlet pipes A pipe 131 and B pipe 132 led out from the A port and B port of the hydraulic directional valve 2 are respectively connected to the cylinder three-ways on both sides to push the piston in the hydraulic cylinder to move; the hydraulic directional valve is provided with a P inlet port 21 and a T drain port 22 connected through a drain three-way 23, and two P pressure guiding pipes 101 are led out from the port one 24 on the P inlet port and are respectively connected to the P port of the on-off valves on both sides for inlet liquid; the T drain port is provided with a port two 25 from which two T pressure guiding pipes 102 are led out and are respectively connected to the T port of the on-off valves on both sides for draining liquid; X ports 26 are respectively provided at the valve bottoms 27 at both ends of the hydraulic directional valve, and one X pressure guiding pipe 103 is led out from each to be connected to the X port of the on-off valve on the same side for inlet liquid to push the spool of the directional valve to move; one Y pressure guiding pipe 104 is led out from the valve bottom 121 of each on-off valve and is connected to the Y port of the on-off valve on the other side to push the spool of the on-off valve to move;

[0008] The A port and B port of the hydraulic directional valve 2 are alternately connected through the movement of its spool to switch the oil circuits communicating with the P inlet port and the T drain port, thereby changing the inlet and outlet liquid directions.

[0009] The described oil well oil and gas collection device, wherein the hydraulic cylinder 1 includes a cylinder body, a left piston 17, a right piston 18, a piston pull rod 141, and a sealing guide sleeve 14 inside the cylinder body. Four cavities are arranged inside the cylinder body, including symmetrically arranged A and B oil cavities at both ends and two air cavities symmetrically arranged between the two oil cavities; the sealing guide sleeve 14 is fixed in the air cavity in the middle of the cylinder, the piston pull rod passes through the guide sleeve and is in sliding fit with it, and both ends of the piston pull rod passing through both sides of the guide sleeve are respectively connected to the left piston and the right piston. Two of the air cavities 15 are formed between the left piston or the right piston and the sealing guide sleeve 14; an A oil cavity 161 is formed between the left piston and the three-way, and a B oil cavity 162 is formed between the right piston and the three-way; the sealing guide sleeve 14 is respectively provided with an air inlet hole 19 communicating with each air cavity and an exhaust hole 20 for exhausting gas from the air cavity; the air inlet hole is connected to the oil well exhaust casing through an air inlet check valve assembly 29, and the exhaust hole is connected to the T drain port of the drain three-way of the hydraulic directional valve through an exhaust check valve assembly 28.

[0010] The described oil well oil and gas collection device, wherein the spool of the on-off valve moves inside its valve body and the inner end enters the A or B oil cavity, and is pushed in and out by the left piston or the right piston; the oil in the A oil cavity or B oil cavity enters and exits through the A pipe 131 or B pipe 132, pushing the left piston and the right piston to move synchronously, and the gas in the two air cavities 15 is pumped and discharged through the air inlet hole and the exhaust hole 20.

[0011] The described oil well oil and gas collection device, wherein the hydraulic directional control valve 2 includes a valve body, a spool, valve bottoms 27 at the left and right ends, a P liquid inlet 21 and a nipple assembly 271, a T drain port 22 connected to a drain tee 23, an intelligent pressure sensor and a pressure gauge; the spool is placed inside the valve body, the valve bottoms are installed at both ends of the valve body and X ports are provided at both ends, the P liquid inlet is connected to the two sides of the valve body through the nipple assembly 271, and the T drain port is connected through the drain tee; the A port and B port of the hydraulic directional control valve are switched and alternately communicated with the oil circuits of the P liquid inlet and the T drain port by the movement of the spool, and the hydraulic directional control valve is provided with 2 T ports connected to the drain tee for draining; the X pressure guiding pipes on both sides switch and alternately push the spool of the hydraulic directional control valve to move and switch.

[0012] The described oil well oil and gas collection device, wherein the on-off valve 12 includes a valve body, a spool, a valve bottom 121, and on-off valve T, Y, P, and X ports, which are respectively connected to each pressure guiding pipe through an oil circuit block, and the on-off valve is provided with a port flange 122 connected to the flange of the oil cylinder tee.

[0013] The described oil well oil and gas collection device, wherein the on-off valve switches and alternately communicates the oil circuits of the P port with the Y port or the X port by the movement of its spool. When the oil circuit between the P port and the Y port is communicated, it pushes the spool of the on-off valve to move, and when the oil circuit between the P port and the X port is communicated, it pushes the spool of the hydraulic directional control valve to move.

[0014] The described oil well oil and gas collection device, wherein the P liquid inlet is connected to the oil well drainage pipeline, and the T drain port 22 is connected to the oil well inlet pipeline.

[0015] The described oil well oil and gas collection device, wherein a vent valve 100 is provided on the pressure guiding pipe.

[0016] The described oil well oil and gas collection device, wherein the hydraulic directional control valve is provided with a safety overflow valve, which is communicated with the inlet pipeline at the drain tee port of the T drain port.

[0017] The described oil well oil and gas collection device, wherein the gas in the gas chamber is discharged into the drain tee, mixed with the oil and then discharged into the oil well inlet pipeline, and finally enters the centralized combined station for storage and recovery.

[0018] Technical features of the present invention:

[0019] 1. The on-off valve is driven by power liquid for commutation and switching, accurate and in place, without pressure impact.

[0020] 2. The pressure guiding pipe and the vent valve on the pressure guiding pipe can ensure convenient maintenance, solve pipeline blockage, and accurately judge accidents.

[0021] 3. The intake valve assembly can automatically open and close according to the set pressure, preventing accidents such as casing deformation caused by the evacuation of casing gas.

[0022] 4. The intelligent sensing pressure gauge can achieve remote transmission monitoring.

[0023] Advantages of the present invention:

[0024] The present invention uses the hydrodynamic force of the oil well during the upstroke for liquid drainage as the driving power energy source. After the liquid entering the present invention completes the power liquid cycle, it is discharged into the inlet pipeline of the oil well through the T-port liquid drainage three-way of the present invention. After the air cavity completes the unit function of exhausting and sucking air from the oil well casing, the air in the air cavity enters the liquid drainage pipeline three-way, mixes with the oil, and is discharged into the inlet pipeline of the oil well, and then enters the centralized combined station for storage, recovery and utilization. The present invention realizes the use of the power source of the oil well liquid drainage, realizes the oil and gas collection of the oil well, completes the automatic operation of the reciprocating oil cylinder of the present invention, realizes the exhausting and sucking air of the device of the present invention, achieves the purpose of recovering the casing gas of the oil well, effectively solves the production technical problem of casing gas pressure buildup, and can also recover and utilize 90% of the low-pressure oil well casing gas, effectively utilizes the gas resources, eliminates the pollution to the atmosphere and the harm to humans caused by the external discharge of the oil well casing gas, and achieves zero emission of the oil well casing gas. Description of the drawings

[0025] Figure 1 is a three-dimensional schematic diagram of the overall structure of an oil and gas collection device of the present invention.

[0026] Figure 2 is a top view schematic diagram of the structure of the present invention.

[0027] Figure 3 is a front view schematic diagram of the structure of the present invention.

[0028] Figure 4 is a schematic diagram of the hydraulic directional control valve channel, port A, and port B.

[0029] Figure 5 is a schematic diagram of the hydraulic cylinder structure.

[0030] Figure 6 is a schematic diagram of the piston and pull rod of the hydraulic cylinder.

[0031] Figure 7 、 8 is a schematic diagram of the on-off valve structure.

[0032] Figure 8 、 10 are the top view and side view of the hydraulic directional control valve structure;

[0033] Figure 11 、 12 is a schematic diagram of the working principle of the present invention.

[0034] Description of the drawing reference numerals:

[0035] Hydraulic cylinder 1, cylinder three-way joint 11, on-off valve 12, on-off valve bottom 121, port flange 122, oil circuit block 123, vent valve 124, A pipe 131, B pipe 132, sealing guide sleeve 14, piston pull rod 141, air chamber 15, A oil chamber 161, B oil chamber 162, left piston 17, right piston 18, air inlet hole 19, exhaust hole 20

[0036] Hydraulic reversing valve 2, P liquid inlet 21, T liquid outlet 22, liquid discharge three-way joint 23, port one 24, port two 25, X port 26, hydraulic reversing valve bottom 27, short joint assembly 271, exhaust check valve assembly 28, intake check valve assembly 29

[0037] P pressure guiding pipe 101, T pressure guiding pipe 102, X pressure guiding pipe 103, Y pressure guiding pipe 104, vent valve 100 Specific embodiments

[0038] The specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0039] The oil and gas collection device for oil wells of the present invention uses the liquid discharge of the oil well pumping unit as the driving power source to drive the hydraulic reciprocating cylinder of the present invention, realizing automatic reciprocating operation. It completes the suction, pressurization, and exhaust of the casing gas in the oil well, achieving the recovery of the casing gas in the oil well.

[0040] See Figures 1-4 As shown, an oil and gas collection device for oil wells of the present invention includes a hydraulic reversing valve 2 and a hydraulic cylinder 1; both ends of the hydraulic cylinder 1 are respectively connected to a cylinder three-way joint 11, and both ends are connected to an on-off valve 12 through the cylinder three-way joint; two inlet and outlet liquid pipes A pipe 131 and B pipe 132 led out from the A port and B port of the hydraulic reversing valve 2 are respectively connected to the cylinder three-way joints on both sides to push the piston in the hydraulic cylinder to move; the hydraulic reversing valve is provided with a P liquid inlet 21 and a T liquid outlet 22 connected through a liquid discharge three-way joint 23. Two P pressure guiding pipes 101 are led out from the port one 24 provided on the P liquid inlet and are respectively connected to the P port of the on-off valves on both sides for liquid inlet; two T pressure guiding pipes 102 are led out from the port two 25 provided on the T liquid outlet and are respectively connected to the T port of the on-off valves on both sides for liquid discharge; X ports 26 are respectively provided at the valve bottoms 27 at both ends of the hydraulic reversing valve, and one X pressure guiding pipe 103 is respectively led out from each X port to connect to the X port of the on-off valve on the same side to push the spool of the reversing valve to move; one Y pressure guiding pipe 104 is respectively led out from the valve bottom 121 of each on-off valve to connect to the Y port of the on-off valve on the other side to push the spool of the on-off valve to move;

[0041] The A port and B port of the hydraulic reversing valve 2 are alternately communicated through the movement of its spool to change the oil circuit connected to the P liquid inlet and T liquid outlet, thereby changing the inlet and outlet liquid directions.

[0042] See Figure 5 、 6As shown in the figure, for the described oil well oil and gas collection device, the hydraulic cylinder 1 includes a cylinder body, a left piston 17, a right piston 18, a piston pull rod 141, and a sealing guide sleeve 14 inside the cylinder body. Four chambers are arranged inside the cylinder body, including symmetrically arranged A and B oil chambers at both ends and two gas chambers symmetrically arranged between the two oil chambers. The sealing guide sleeve 14 is fixed in the gas chamber in the middle of the cylinder. The piston pull rod passes through the guide sleeve and is in sliding fit with it. The two ends of the piston pull rod passing through both sides of the guide sleeve are respectively connected to the left piston and the right piston. Two such gas chambers 15 are formed between the left piston or the right piston and the sealing guide sleeve 14. An A oil chamber 161 is formed between the left piston and the three-way joint, and a B oil chamber 162 is formed between the right piston and the three-way joint. The sealing guide sleeve 14 is respectively provided with an air inlet hole 19 for connecting each gas chamber and an exhaust hole 20 for exhausting gas from the gas chamber. The air inlet hole is connected to the oil well exhaust casing through an air inlet check valve assembly 29, and the exhaust hole is connected to the T drain port of the hydraulic directional control valve drain three-way joint through an exhaust check valve assembly 28.

[0043] See Figure 7 , 8 As shown in the figure, for the described oil well oil and gas collection device, the on-off valve spool moves inside its valve body and the inner end enters the A or B oil chamber, and is pushed in and out by the left piston or the right piston. The oil in the A oil chamber or B oil chamber enters and exits through the A pipe 131 or B pipe 132, pushing the left piston and the right piston to move synchronously. The gas in the two gas chambers 15 is pumped and discharged through the air inlet hole and the exhaust hole 20.

[0044] See Figure 9 , 10 As shown in the figure, for the described oil well oil and gas collection device, the hydraulic directional control valve 2 includes a valve body, a spool, valve bottoms 27 at the left and right ends, a P liquid inlet 21, and a short joint assembly 271. The T drain port 22 is connected to a drain three-way joint 23, and an intelligent pressure sensor and a pressure gauge are provided. The spool is placed inside the valve body. The valve bottoms are installed at both ends of the valve body and X ports are provided on both. The P liquid inlet is connected to both sides of the valve body through the short joint assembly 271, and the T drain port is connected through the drain three-way joint. The hydraulic directional control valve sets the A port and the B port to alternately connect and switch the oil circuits with the P liquid inlet and the T drain port through the movement of the spool. The hydraulic directional control valve has 2 T ports connected to the drain three-way joint for draining. The X pressure guiding pipes on both sides alternately push the spool of the hydraulic directional control valve to move and switch.

[0045] See Figure 3 As shown in the figure, for the described oil well oil and gas collection device, the on-off valve 12 includes a valve body, a spool, and a valve bottom 121, and on-off valve T, Y, P, and X ports are provided, which are respectively connected to each pressure guiding pipe through an oil circuit block. The on-off valve is provided with a port flange 122 connected to the cylinder three-way flange.

[0046] The described oil well oil and gas collection device, wherein, through the movement of its spool, the on-off valve alternately switches and communicates the oil circuit between the P port and the Y port or the X port. The communication of the P port and the Y port oil circuit drives the movement of the spool of the on-off valve, and the communication of the P port and the X port oil circuit drives the movement of the spool of the hydraulic directional control valve.

[0047] The described oil well oil and gas collection device, wherein, the P liquid inlet is connected to the oil well drainage pipeline, and the T drainage port 22 is connected to the oil well inlet pipeline.

[0048] The described oil well oil and gas collection device, wherein, a vent valve 100 is provided on the pressure guiding pipe.

[0049] The described oil well oil and gas collection device, wherein, a safety overflow valve is provided on the hydraulic directional control valve, which is communicated with the inlet pipeline at the drainage tee port of the T drainage port.

[0050] The described oil well oil and gas collection device, wherein, the gas in the gas chamber is discharged into the drainage tee, mixed with the oil and then discharged into the oil well inlet pipeline, and finally enters the centralized combined station for storage and recovery.

[0051] Among them, the P pressure guiding pipe is the power liquid pressure guiding pipe, the T pressure guiding pipe is the normal back pressure guiding pipe, which plays a role in balancing the spool. The Y pressure guiding pipe is the pressure introduced from the P port to the Y port when the on-off valve switches, which drives the one-way commutation of the spool of the on-off valve. When the on-off valve is opened, the oil cylinder piston drives the commutation of the spool of the on-off valve. When returning, the pressure of the P port with Y port pressure guides the spool to return to its position, so it is called one-way pressure commutation; the X port pressure guiding pipe is the pressure introduced into the P port after the oil passage is switched, which drives the commutation of the main spool of the hydraulic directional control valve.

[0052] Connection sequence of the pressure guiding pipes of the on-off valve: The P port pressure guiding pipe of the on-off valve is a three-way type pressure guiding pipe, and the port pressure introduction end is connected to the P liquid inlet of the main valve of the hydraulic directional control valve, and is connected to one of the P port ends of the inlet short joint assembly. The left side of the pressure guiding pipe is connected to the P port oil port on the left on-off valve body, and the right side is connected to the P port oil port of the right on-off valve body. The T port pressure guiding pipes are all three-way pressure guiding pipes, the upper end is connected to the drainage tee port, the left end is connected to the T port of the left on-off valve, and the right side is connected to the T port oil port of the right on-off valve body. The present invention is provided with two on-off valves on the left and right, each on-off valve is provided with two T port oil holes, the left and right T port pressure guiding pipes are three-way pressure guiding pipes, the upper end of the pressure guiding pipe is connected to the drainage tee port, and the lower ends of the pressure guiding pipes are respectively connected to the T port oil holes of the left and right on-off valves.

[0053] The following further explains each component of the present invention as follows:

[0054] 1. The hydraulic reversing control main valve includes a valve body, a spool, a valve bottom, a safety overflow valve block, a T-port drainage tee, a P-inlet connection stub, an exhaust check valve at the T-drain port end, an exhaust check valve quick plug, and a safety overflow valve. Its functional unit in the device of the present invention is to complete the liquid intake and discharge of the hydraulic cylinder and the switching of the oil ports. It controls the flow direction of the liquid intake and discharge of the reciprocating cylinder, and orderly enters and exits within the set reciprocating stroke. It completes the unit functions of the liquid intake and discharge, air extraction and exhaust of the reciprocating cylinder. When a failure occurs in the present invention, the pressure of the present invention rises, and the overflow valve will automatically open and communicate with the inlet pipeline at the port of the drainage tee of the T-port, which is a unit functional accessory that does not affect the normal production of the oil well.

[0055] 2. The hydraulic cylinder is divided into an oil chamber and a gas chamber. The oil chamber is the channel for the power liquid to enter and exit. The functions of the air intake chamber and the exhaust chamber are to complete the extraction and discharge of the casing natural gas of the well. When the liquid enters from the left side of the oil chamber, the liquid is discharged from the right side of the oil chamber, the air is exhausted from the left side of the gas chamber, and the air enters from the right side; the liquid discharged from the oil chamber is discharged into the inlet pipeline, and the gas in the gas chamber is discharged into the drainage tee of the hydraulic reversing valve main valve and mixed with the liquid in the oil chamber and then discharged into the inlet pipeline.

[0056] The piston pull rod inside the cylinder passes through the pull rod sealing sliding sleeve and is connected to the left and right pistons inside the cylinder. The cylinder pull rod sealing sliding sleeve is fixed in the middle of the cylinder to complete the combination of the unit accessories inside the cylinder. The hydraulic on-off valves at both ends of the cylinder are connected to the cylinder liquid intake and discharge tee through flanges. The liquid intake and discharge tee is connected to the cylinder, and the liquid intake and discharge tee is connected to the A and B liquid intake and discharge pipes. The A and B pipes are connected to the A and B port oil channels of the hydraulic control reversing valve. The pressure guiding pipe of the X port is connected to the left and right valve bottoms of the hydraulic reversing valve, the pressure guiding pipe of the P port is connected to the P ports on the left and right on-off valves, the Y pressure guiding pipe is the connection between the right valve bottom and the Y port of the left valve body, and the Y port of the right valve body is connected to the left valve bottom to form a cross connection between the left and right valves.

[0057] 3. The intake check valve assembly of the present invention has an automatic opening and closing function, and can automatically open and close according to the level of the casing gas pressure of the oil well, and the opening and closing pressure is manually set.

[0058] The working principle of the present invention:

[0059] The present invention uses the power liquid of the liquid discharged by the pumping unit as the driving power energy of the present invention to complete the hydraulic reciprocating cylinder, realize automatic reciprocating operation, and complete the suction, pressurization and transportation of the casing gas of the oil well. The P-inlet of the present invention is connected to the oil well liquid discharge pipeline, and the T-drain port is connected to the oil well inlet pipeline; when it is confirmed that the present invention is started, when the crude oil of the oil well enters the hydraulic reversing valve of the present invention from the P-inlet of the present invention, the spool of the hydraulic reversing valve will complete an initial action under the push of the liquid, achieving the switching of the liquid intake and discharge A and B port oil channels of the hydraulic reversing valve.

[0060] See Figure 11As shown in the figure, when the X pressure guiding pipe of the left on-off valve pushes the spool of the hydraulic reversing valve 2 to move from left to right, the PA oil circuit (the P port and the A port oil circuits are connected) and the TB oil circuit (the T port and the B port oil circuits are connected) inside the hydraulic reversing valve are connected respectively, and are converted to the liquid inlet at port A and the liquid discharge at port B; subsequently, the liquid enters through pipe A and is discharged through pipe B; the oil chamber A of the hydraulic cylinder 1 is filled with liquid, pushing the left piston and the right piston in the A and B chambers to move synchronously to the right. At this time, the left air chamber discharges air and the right air chamber sucks air. When moving to the set stroke position, the right piston in chamber B pushes the spool of the right on-off valve to move to the right, closing the PX oil circuit (the P port and the X port oil circuits are cut off) inside the right on-off valve, and switching to the PY oil circuit (the P port and the Y port oil circuits are connected) of the right on-off valve. The power liquid of the PY oil circuit of the right on-off valve enters the bottom of the left on-off valve through the Y pressure guiding pipe connected to the Y port of the right on-off valve, pushing the spool inside the valve body of the left on-off valve to move to the right. After that, the PY oil circuit of the left on-off valve is closed, and the PY oil circuit of the left on-off valve is switched to the PX oil circuit. When the oil circuit of the left on-off valve reaches the PX oil circuit position, the pressure oil at port X enters the left bottom of the hydraulic reversing valve through the X pressure guiding pipe at port X, pushing the spool of the hydraulic reversing valve to move to the right for commutation. The spool of the hydraulic reversing valve moves from the left position to the right position. At this time, the spool position of the left on-off valve is the upper position where PX is connected, as shown in this Figure 11 figure;

[0061] When the spool of the left on-off valve moves to the right to the set stroke position, the PX oil circuit inside the left on-off valve is closed, and it is switched to the PY oil circuit of the left on-off valve. The power liquid of the PY oil circuit of the left on-off valve enters the bottom of the right on-off valve through the Y pressure guiding pipe connected to the Y port of the left on-off valve, pushing the spool inside the valve body of the right on-off valve to move to the left, closing the PY oil circuit of the right on-off valve, Switch the right on-off valve PY The oil circuit to the PX oil circuit and enters the right bottom of the hydraulic reversing valve through the X pressure guiding pipe at port X of the right on-off valve, pushing the spool of the hydraulic reversing valve to move to the left for commutation. The spool of the hydraulic reversing valve moves from the right position to the left position; making the PB oil circuit and the TA oil circuit inside it connected respectively, and the hydraulic reversing valve is converted to the liquid inlet at port B and the liquid discharge at port A; subsequently, the liquid enters through pipe B and is discharged through pipe A; the oil chamber B of the hydraulic cylinder 1 is filled with liquid, pushing the right piston and the left piston in chamber B to move synchronously to the left. At this time, the right air chamber discharges air and the left air chamber sucks air. The spool position of the right on-off valve is the upper position where PX is connected; see Figure 12 figure;

[0062] When the spool of the right on-off valve moves leftward to the set stroke position, the PX oil passage in the right on-off valve is closed, and the PY oil passage of the right on-off valve is switched. The power fluid in the PY oil passage of the right on-off valve enters the valve bottom of the left on-off valve through the Y pressure guiding pipe connected to the Y port of the right on-off valve, pushing the spool in the valve body of the left on-off valve to move rightward, closing the PY oil passage of the left on-off valve, switching the PY oil passage of the left on-off valve to the PX oil passage, and entering the left valve bottom of the hydraulic directional control valve through the X pressure guiding pipe at the X port of the left on-off valve, pushing the spool of the hydraulic directional control valve to move rightward for commutation. The spool of the hydraulic directional control valve moves from the left position to the right; such reciprocating cycle switching is performed. At the same time, when the left piston and the right piston move back and forth, the exhaust and intake cycle switching of the left and right air chambers is completed;

[0063] The liquid enters the device of the present invention through the liquid inlet short joint at the P port. After the liquid entering the present invention completes the power fluid cycle, it is discharged into the inlet pipeline of the oil well through the drain liquid tee at the T port of the present invention. After the air chamber completes the unit function of exhaust and intake, the gas in the air chamber enters the drain liquid pipeline tee, is mixed with the oil, and is discharged into the inlet pipeline of the oil well, and enters the centralized combined station for storage, recovery and utilization, realizing that the present invention utilizes the power source of the oil well drain liquid to complete the automatic operation of the reciprocating oil cylinder of the present invention, realizing the exhaust and intake of the device of the present invention, achieving the purpose of recovering the casing gas of the oil well, and at the same time realizing the most advanced oil and gas co-production advanced process flow.

[0064] The present invention utilizes the hydraulic power of the oil well drain liquid during the upstroke of the oil well as the driving power energy of the present invention, effectively solves the production technical problem of casing gas backpressure, and can also recover and utilize 90% of the casing gas of low-pressure oil wells, effectively utilizes the gas resources, eliminates the pollution to the atmosphere and the harm to humans caused by the external discharge of the casing gas of the oil well, and achieves zero emission of the casing gas of the oil well.

Claims

1. An oil well oil and gas collection device, comprising a hydraulic directional control valve and a hydraulic cylinder; characterized in that, Both ends of the hydraulic cylinder (1) are respectively connected to the cylinder three-way joint (11), and both ends are connected to the on-off valve (12) through the cylinder three-way joint; two inlet and outlet pipes A (131) and B (132) led out from the A port and B port of the hydraulic directional control valve (2) are respectively connected to the cylinder three-way joints on both sides to push the piston in the hydraulic cylinder to move; the hydraulic directional control valve is provided with a P inlet port (21) and a T outlet port (22) connected through a drain three-way joint (23). Two P pressure guiding pipes (101) are led out from port one (24) on the P inlet port and are respectively connected to the P port of the on-off valves on both sides for inlet liquid; port two (25) is arranged on the T outlet port and two T pressure guiding pipes (102) are led out and are respectively connected to the T port of the on-off valves on both sides for draining liquid; X ports (26) are arranged at the valve bottoms (27) at both ends of the hydraulic directional control valve and one X pressure guiding pipe (103) is led out from each of them to be connected to the X port of the on-off valve on the same side for inlet liquid to push the spool of the directional control valve to move; one Y pressure guiding pipe (104) is led out from the valve bottom (121) of each on-off valve to be connected to the Y port of the on-off valve on the other side to push the spool of the on-off valve to move; The A port and B port of the hydraulic directional control valve (2) are alternately communicated with the oil circuits of the P inlet port and the T outlet port by the movement and switching of its spool to change the inlet and outlet liquid directions; In the described oil well oil and gas collection device, the hydraulic cylinder (1) includes a cylinder body, a left piston (17), a right piston (18), a piston pull rod (141), and a sealing guide sleeve (14) inside the cylinder body. Four cavities are arranged inside the cylinder body, including A and B oil cavities symmetrically arranged at both ends and two gas cavities symmetrically arranged between the two oil cavities; the sealing guide sleeve (14) is fixed in the gas cavity in the middle of the cylinder. The piston pull rod passes through the guide sleeve and is in sliding fit with it. Both ends of the piston pull rod passing through both sides of the guide sleeve are respectively connected to the left piston and the right piston. Two of the described gas cavities (15) are formed between the left piston or the right piston and the sealing guide sleeve (14); an A oil cavity (161) is formed between the left piston and the three-way joint, and a B oil cavity (162) is formed between the right piston and the three-way joint; the sealing guide sleeve (14) is respectively provided with an air inlet hole (19) for communicating each gas cavity and an exhaust hole (20) for exhausting gas from the gas cavity; the air inlet hole is connected to the oil well exhaust casing through an air inlet check valve assembly (29), and the exhaust hole is connected to the T outlet port of the drain three-way joint of the hydraulic directional control valve through an exhaust check valve assembly (28); In the described oil well oil and gas collection device, the spool of the on-off valve moves in its valve body and the inner end head enters the A or B oil cavity and is pushed in and out by the left piston or the right piston; the oil liquid in the A oil cavity or B oil cavity enters and exits through the A pipe (131) or B pipe (132), pushing the left piston and the right piston to move synchronously. The gas in the two described gas cavities (15) is pumped and discharged through the air inlet hole and the exhaust hole (20); A described oil well oil and gas collection device, wherein the hydraulic directional control valve (2) comprises a valve body, a spool, valve bottoms (27) at the left and right ends, a P liquid inlet (21) and a nipple assembly (271), a T drain port (22) connected to a drain tee (23), an intelligent pressure sensor and a pressure gauge; the spool is placed inside the valve body, the valve bottoms are installed at both ends of the valve body and X ports are arranged on both; the P liquid inlet is connected to both sides of the valve body through the nipple assembly (271), and the T drain port is connected through the drain tee; the A port and B port of the hydraulic directional control valve are alternately connected and communicated with the oil circuits of the P liquid inlet and the T drain port by the movement of the spool inside the valve, and the hydraulic directional control valve is provided with 2 T ports connected to the drain tee for draining; the X pressure guiding pipes on both sides alternately push the spool of the hydraulic directional control valve to move and switch; A described oil well oil and gas collection device, wherein the on-off valve (12) comprises a valve body, a spool, a valve bottom (121), and on-off valve T, Y, P, X ports are arranged, and are respectively connected to each pressure guiding pipe through an oil circuit block, and the on-off valve is provided with a port flange (122) connected to the flange of the oil cylinder tee.

2. The oil and gas collection device for oil wells according to claim 1, characterized in that, Through the movement of its spool, the on-off valve alternately switches and communicates the oil circuits between the P port and the Y port or the X port. When the oil circuit between the P port and the Y port is communicated, it pushes the spool of the on-off valve to move, and when the oil circuit between the P port and the X port is communicated, it pushes the spool of the hydraulic directional control valve to move.

3. The oil and gas collection device for oil wells according to claim 1, characterized in that The P liquid inlet is connected to the oil well drain pipeline, and the T drain port (22) is connected to the oil well inlet pipeline.

4. The oil and gas collection device for oil wells according to claim 1, characterized in that, A vent valve (100) is arranged on the pressure guiding pipe.

5. The oil and gas collection device for oil wells according to claim 1, characterized in that, The hydraulic directional control valve is provided with a safety overflow valve, which is communicated with the inlet pipeline at the drain tee port of the T drain port.

6. The oil and gas collection device for oil wells according to claim 1, wherein, The gas in the gas cavity is discharged into the drain tee, mixed with the oil and then discharged into the oil well inlet pipeline, and finally enters the centralized combined station for storage and recovery.

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