Special pump pry for oil and gas well yield increase and carbon dioxide huff and puff pressurization

Abstract

The invention discloses a special pump skid for oil and gas well yield increase and carbon dioxide huff and puff pressurization, relates to the technical field of carbon dioxide oil displacement, and adopts an injection system consisting of a skid-mounted base integrated storage tank, double injection tanks, an injection pump, a fluid infusion pump and a three-way reversing valve. A partition bag A is arranged in the storage tank to divide the space into a liquid COstorage area and a pressure adjusting area, and the pressure of the storage tank is adjusted by filling and discharging media. The double injection tanks achieve an alternate working mode through the three-way reversing valve A / B. When the injection pump injects COs into one injection tank in a pressurized mode through the three-way valve A, the liquid supplementing pump supplements liquid COs into the other injection tank synchronously through the three-way valve B. The structure enables liquid-state CO not to be in contact with the injection pump in the whole process, the gas blocking phenomenon is thoroughly eliminated, and the pump efficiency stability is guaranteed. An original separation bag pressure compensation mechanism and a three-way valve set are cooperatively controlled, so that the pressure of the storage tank is constant, the injection flow is continuous and controllable, the problems of pressure fluctuation and pumping interruption caused by phase change of traditional equipment are solved, and the COO injection efficiency is remarkably improved.

Description

Technical Field

[0001] The invention belongs to the technical field of carbon dioxide oil recovery, and in particular relates to a special pump skid for increasing the production of carbon dioxide through throughput and pressure boosting in oil and gas wells. Background Art

[0002] Carbon dioxide huff and puff recovery technology is one of the specific application forms of carbon dioxide recovery technology. Carbon dioxide huff and puff recovery technology is a production-increasing technology that injects liquid carbon dioxide into the oil layer under a certain pressure to make it miscible with the formation crude oil, reduce the viscosity of the crude oil, solve the formation blockage problem, and use the expansion effect of carbon dioxide to supplement the formation energy, thereby increasing the recovery rate of the oil well.

[0003] The main structure of the existing carbon dioxide injection pump skid includes a carbon dioxide injection system and a carbon dioxide recovery system, wherein the carbon dioxide injection system includes a storage tank, a liquid feeding pump, an injection pipeline, an injection pump, etc. In order to prevent the liquid carbon dioxide from gasifying in the injection pipeline and the injection pump, the injection pipeline and the injection pump need to be pre-cooled. The injection pumps used in the prior art are mostly plunger pumps (because the plunger pump can provide a higher working pressure). The plunger pump will continuously generate heat during the operation (friction between the plunger and the cylinder generates heat). The heat will cause a small amount of gasification of the liquid carbon dioxide. The gasified carbon dioxide is in the cylinder, which will reduce the pump efficiency (actual output flow and theoretical output flow) on the one hand, and reduce the pumping pressure (discharge pressure of the pump) on the other hand. In order to prevent the plunger pump from heating up, the prior art usually sets a refrigeration system on the structure of the plunger pump, and the refrigeration system is used to cool the plunger pump. However, such a setting makes the structure of the plunger pump more complicated and the maintenance more inconvenient.

[0004] In addition, the storage tank is used to store liquid carbon dioxide. To ensure that the liquid carbon dioxide can be stored at room temperature, the pressure inside the tank needs to be maintained at 2.2-2.5Mpa (a pressure drop will cause the liquid carbon dioxide to gasify). As the liquid carbon dioxide continues to flow out of the tank, the pressure inside the tank drops. In order to continue to maintain the pressure of 2.2-2.5Mpa, the existing technology has to replenish gas into the tank multiple times (replenished with carbon dioxide gas). The defects of replenishing gas are: first, special filling equipment is required; second, since the gas is compressible, a large amount of carbon dioxide is required for replenishment, and the carbon dioxide gas replenished into the tank is eventually discharged into the atmosphere, causing pollution. Summary of the invention

[0005] In order to solve the two defects mentioned in the background technology, the present invention provides a special pump skid for increasing the production of carbon dioxide in oil and gas wells and increasing the pressure. The injection pump of the present invention is not directly used to pump liquid carbon dioxide, thereby avoiding the gasification of carbon dioxide by the working heat of the pump, and avoiding the adverse effects of the gas in the pump on the pump efficiency and pumping pressure. During the carbon dioxide filling stage of the present invention, the remaining space in the storage tank is supplemented by the partition bag A, and the partition bag A is filled with gas or liquid. The expansion pressure in the storage tank is balanced by the release of the gas or liquid in the partition bag A. During the injection stage, the outflow of liquid carbon dioxide in the storage tank is almost balanced with the inflow of water, thereby ensuring the stability of the tank pressure during the injection stage, and then ensuring the stability of the state of carbon dioxide, which is conducive to the normal operation of the entire pump skid.

[0006] The technical solution provided by the present invention is: a special pump skid for increasing the production of carbon dioxide in oil and gas wells by throughput and pressure boosting, comprising a base, on which an injection system is arranged; the injection system comprises a storage tank, an injection tank, an injection pump, a liquid replenishing pump, a three-way reversing valve A, a three-way reversing valve B and a three-way reversing valve C; flanges A are arranged at both ends of the storage tank, a separation bag A is arranged in the storage tank, and both ends of the separation bag A are fixedly connected to the flange A, respectively, and liquid or gas can be injected into the separation bag A through the flange A, a liquid filling port is arranged above the storage tank, and liquid carbon dioxide is injected into the space inside the storage tank and outside the separation bag A through the liquid filling port, and the separation bag A has a function of separating liquid. Function; During the filling stage of liquid carbon dioxide, air or water is filled in the separation bag A. When the carbon dioxide liquid in the storage tank expands in volume due to an increase in temperature or a change in pressure, the air or water in the separation bag A is released to reduce the pressure in the storage tank. It can be seen that the present application avoids the problem of emitting carbon dioxide into the air; There are two injection tanks, namely the first injection tank and the second injection tank, flanges B are respectively provided at both ends of the injection tanks, and separation bags B are provided in the injection tanks. The separation bag B is used to separate the two liquids, and the two ends of the separation bag B are respectively fixedly connected to the flanges B; Each three-way reversing valve has a main port and two branch ports. The sub-ports are switched to realize that one of the sub-ports is connected to the main port, and the other sub-port is disconnected from the main port; the first injection tank is connected to the lower part of the storage tank through a pipeline and a one-way valve A is arranged on the pipeline, the first injection tank is also connected to the sub-port of the three-way reversing valve C, the second injection tank is connected to the storage tank through a pipeline and a one-way valve B is arranged on the pipeline, the second injection tank is also connected to the sub-port of the three-way reversing valve C, the main port of the three-way reversing valve C is connected to the wellhead, the outlet end of the injection pump is connected to the main port of the three-way reversing valve A, and the two sub-ports of the three-way reversing valve A are respectively connected to one of the flanges B of the first injection tank and one of the flanges of the second injection tank The first injection tank is connected to the third injection tank through the third injection tank flange B, the other flange B of the first injection tank is connected to the branch port of the three-way reversing valve B through a pipeline, and a constant pressure opening valve A and a one-way valve C are provided on the pipeline. The other flange B of the second injection tank is connected to the branch port of the three-way reversing valve B through a pipeline, and a constant pressure opening valve B and a one-way valve D are provided on the pipeline. The main port of the three-way reversing valve B is connected to the inlet end of the refilling pump, and the outlet end of the refilling pump is connected to one of the flanges A of the storage tank through a pipeline, and a one-way valve E is provided on the pipeline. The liquid carbon dioxide does not directly contact the injection pump, so the injection pump will not have the problem of air blockage, and the pump efficiency and pumping pressure of the injection pump will not be adversely affected. At the same time, during the carbon dioxide injection stage, the real-time outflow of carbon dioxide in the storage tank is almost the same as the real-time water injection volume, so the pressure in the storage tank is stable.

[0007] A further technical solution is that a balancing tank is arranged on the pipeline upstream of the three-way reversing valve B sub-port. The balancing tank is filled with liquid to ensure that there is liquid at the inlet end of the liquid replenishing pump at the initial working stage.

[0008] A further technical solution is: the upper end of the injection tank is connected with an exhaust pipe, and an exhaust valve is installed on the exhaust pipe; the gas in the injection tank is discharged through the exhaust valve.

[0009] A further technical solution is: a flow sensor, a temperature sensor and a switch valve A are arranged on the pipeline upstream of the inlet end of the injection pump; a pressure sensor is arranged on the pipeline between the three-way reversing valve A and the two injection tanks; a flow sensor, a temperature sensor, a pressure sensor and a switch valve B are arranged on the pipeline between the liquid replenishment pump and the flange A; a flow sensor, a temperature sensor, a pressure sensor and a switch valve C are arranged on the pipeline between the three-way reversing valve C and the wellhead.

[0010] A further technical solution is: the separation bag B passes through the hole in the center of the flange B, a support sleeve is provided in the central hole of the neck of the flange B, the support sleeve is located inside the separation bag B, and is used to open the separation bag B from the inside, and a pressing sleeve is provided in the central hole at the port of the flange B, and the pressing sleeve is used to firmly press the end of the separation bag B onto the flange B, and the pressing sleeve and the support sleeve are connected by threads.

[0011] Compared with the prior art, the beneficial effects of the present invention are: 1. Prior art, taking a common 20 cubic meter carbon dioxide storage tank as an example, its filling volume should generally not exceed 15 cubic meters, and a certain amount of space is reserved to prevent the carbon dioxide liquid from expanding in volume when the temperature rises or the pressure changes, causing the storage tank to be overpressured. It can be seen that the prior art storage tank reserves at least 5 cubic meters for filling carbon dioxide gas, and the final destination of this carbon dioxide exceeding 5 cubic meters is to be discharged into the atmosphere, causing greenhouse gas hazards. This application also takes a common 20 cubic meter carbon dioxide storage tank as an example, and its liquid filling volume does not exceed 15 cubic meters. The remaining space is occupied by the partition bag A, which is filled with air or water. In the end, the discharge of air or water in the partition bag A will not cause environmental pollution. This greatly reduces the use of carbon dioxide gas and the final emission. When the carbon dioxide liquid in the storage tank expands in volume when the temperature rises or the pressure changes, the pressure in the storage tank is reduced by releasing the gas or liquid in the partition bag A.

[0012] 2. Most of the existing technologies use a plunger pump to inject liquid carbon dioxide into the wellhead. After the heat generated during the operation of the plunger pump is absorbed by the liquid carbon dioxide, a small amount of liquid carbon dioxide will be gasified, thus affecting the normal use of the plunger pump. The present application adds two injection tanks that work alternately. Water is filled in the partition bag B in the injection tank. The plunger pump increases the hydraulic pressure of the water to increase the hydraulic pressure of the liquid carbon dioxide outside the partition bag B, thereby injecting the liquid carbon dioxide outside the partition bag B into the wellhead. During the entire injection process of the present invention, the plunger pump does not directly contact the liquid carbon dioxide, so the heat generated by the operation of the pump will not be directly transferred to the carbon dioxide liquid, the plunger pump will not have air blockage problems, and the pump efficiency and injection efficiency can be guaranteed.

[0013] 3. In the present application, the real-time outflow of liquid carbon dioxide in the storage tank is almost equal to the real-time water injection into the storage tank, so the pressure in the storage tank always remains constant. Therefore, the state of carbon dioxide in the storage tank is very stable, which is conducive to the normal operation of the entire pump skid system. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0015] Figure 2 It is a structural schematic diagram of the injection tank in the present invention.

[0016] In the figure: the thick black line represents the flow direction of liquid carbon dioxide, and the thin black line represents the flow direction of water.

[0017] In the figure: 1. storage tank; 2. separation bag A; 3. flange A; 4. non-return valve A; 5. exhaust valve; 6. first injection tank; 7. flange B; 8. constant pressure opening valve A; 9. non-return valve C; 10. switch valve A; 11. balance tank; 12. three-way reversing valve A; 13. injection pump; 14. three-way reversing valve B; 15. replenishing pump; 16. three-way reversing valve C; 17. switch valve C; 18. wellhead; 19. non-return valve B; 20. second injection tank; 21. constant pressure opening valve B; 22. non-return valve D; 23. switch valve B; 24. non-return valve E; 25. separation bag B; 26. support sleeve; 27. pressure sleeve; 28. filling port. DETAILED DESCRIPTION

[0018] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0019] refer to Figure 1 The present invention discloses a special pump skid for increasing the production of carbon dioxide in oil and gas wells and boosting the pressure. The structure of the pump skid includes a skid-mounted base, on which an injection system is arranged. The injection system includes a storage tank 1, an injection tank, an injection pump 13, a liquid replenishing pump 15, a three-way reversing valve A12, a three-way reversing valve B14 and a three-way reversing valve C16.

[0020] Flanges A3 are respectively provided at both ends of the storage tank 1, and a separation bag A2 is provided in the storage tank 1. The two ends of the separation bag A2 are respectively fixedly connected to the flanges A3. The existence of the separation bag A2 divides the interior of the storage tank 1 into two independent spaces. Liquid or gas can be injected into the separation bag A2 through the flange A3. A filling port 28 is provided on the top of the storage tank 1. Liquid carbon dioxide can be injected into the space inside the storage tank 1 and outside the separation bag A2 through the filling port 28. Taking a 20 cubic meter storage tank 1 as an example, the filling amount of liquid carbon dioxide does not exceed 15 cubic meters, and the remaining space is all occupied by the separation bag A2. The separation bag A2 has the function of separating liquids; air or water is filled in the separation bag A2. When the carbon dioxide liquid in the storage tank 1 expands in volume when the temperature rises or the pressure changes, the air or water in the separation bag A2 is released to reduce the internal pressure of the entire storage tank 1. It can be seen that the present application avoids the problem of emitting carbon dioxide into the air.

[0021] There are two injection tanks, and the specifications of the two injection tanks are the same. For the convenience of distinction, they are respectively called the first injection tank 6 and the second injection tank 20. Each injection tank is provided with flanges B7 at both ends. A separation bag B25 is provided inside the injection tank. The separation bag B25 is used to separate the two liquids. The two ends of the separation bag B25 are respectively fixedly connected to the flanges B7. The existence of the separation bag B25 divides the inside of the injection tank into two independent spaces. Each three-way reversing valve has a main port and two sub-ports. When the main port is connected to one of the sub-ports, the other sub-port is in a disconnected state with the main port. The two sub-ports realize that one of the sub-ports is connected to the main port through a reversing action, and the other sub-port is disconnected from the main port. The first injection tank 6 is connected to the lower part of the storage tank 1 through a pipeline and a one-way valve A4 is arranged on the pipeline. The first injection tank 6 is also connected to the branch port of the three-way reversing valve C16. The second injection tank 20 is connected to the lower part of the storage tank 1 through a pipeline and a one-way valve B19 is arranged on the pipeline. The second injection tank 20 is also connected to the branch port of the three-way reversing valve C16. The main port of the three-way reversing valve C16 is connected to the wellhead 18. The outlet end of the injection pump 13 is connected to the main port of the three-way reversing valve A12. The two branch ports of the three-way reversing valve A12 are respectively connected to one of the flanges B7 of the first injection tank 6 and the second injection tank 20. One of the flanges B7 of the tank 20 is connected, another flange B7 of the first injection tank 6 is connected to the branch port of the three-way reversing valve B14 through a pipeline, and a constant pressure opening valve A8 and a one-way valve C9 are provided on the pipeline, another flange B7 of the second injection tank 20 is connected to the branch port of the three-way reversing valve B14 through a pipeline, and a constant pressure opening valve B21 and a one-way valve D22 are provided on the pipeline, the main port of the three-way reversing valve B14 is connected to the inlet end of the infusion pump 15, and the outlet end of the infusion pump 15 is connected to one of the flanges A3 of the storage tank 1 through a pipeline, and a one-way valve E24 is provided on the pipeline. In this application, liquid carbon dioxide does not directly contact the injection pump 13, so that the injection pump 13 will not have the problem of air blockage, and the pump efficiency and pumping pressure of the injection pump 13 will not be adversely affected. At the same time, in the carbon dioxide injection stage, the real-time outflow of carbon dioxide in the storage tank 1 is almost the same as the real-time water injection amount into the storage tank 1, so the pressure in the storage tank 1 is stable.

[0022] In the present application, the injection pump 13 is mainly in contact with water, and water will only be vaporized at 100° C. Obviously, the temperature generated by the injection pump 13 during operation cannot vaporize water, so the failure rate of the injection pump 13 during operation is low.

[0023] The working process of this application at the carbon dioxide injection stage is as follows.

[0024] Process 1: At this time, the three-way reversing valve A12 is connected to the flange B7 of the first injection tank 6 and disconnected from the flange B7 of the second injection tank 20; the three-way reversing valve B14 is connected to the flange B7 of the second injection tank 20 and disconnected from the flange B7 of the first injection tank 6; the three-way reversing valve C16 is connected to the first injection tank 6 and disconnected from the second injection tank 20. At this time, the pumped liquid of the injection pump 13 enters the separation bag B25 of the first injection tank 6 through the flange B7, squeezes the carbon dioxide liquid outside the separation bag B25, and increases the carbon dioxide hydraulic pressure in the first injection tank 6. The carbon dioxide liquid reaches the three-way reversing valve C16 through the pipeline, and then enters the wellhead 18 through the switch valve C17. At this time, the pumped liquid of the fluid infusion pump 15 enters the separation bag A2 of the storage tank 1 through the one-way valve E24, the switch valve B23, and the flange A3, increasing the pressure in the storage tank 1 and the hydraulic pressure of the carbon dioxide in the storage tank 1. The carbon dioxide liquid enters the second injection tank 20 through the pipeline, and the separation bag B25 in the second injection tank 20 is squeezed. When the hydraulic pressure exceeds the opening pressure of the constant pressure opening valve B21, the pipeline opens, and the liquid in the separation bag B25 in the second injection tank 20 passes through the constant pressure opening valve B21 and the one-way valve D22 to the balance tank 11.

[0025] Process 2: The three three-way reversing valves are switched at the same time. At this time, the three-way reversing valve A12 is connected to the flange B7 of the second injection tank 20, and is disconnected from the flange B7 of the first injection tank 6; the three-way reversing valve B14 is connected to the flange B7 of the first injection tank 6, and is disconnected from the flange B7 of the second injection tank 20; the three-way reversing valve C16 is connected to the second injection tank 20, and is disconnected from the first injection tank 6. At this time, the pumped liquid of the injection pump 13 enters the separation bag B25 of the second injection tank 20 through the flange B7, squeezing the carbon dioxide liquid outside the separation bag B25, so that the carbon dioxide hydraulic pressure in the second injection tank 20 increases, and the carbon dioxide liquid reaches the three-way reversing valve C16 through the pipeline, and then enters the wellhead 18 through the switch valve C17. At this time, the pumped liquid of the infusion pump 15 enters the separation bag A2 of the storage tank 1 through the one-way valve E24, the switch valve B23, and the flange A3, increasing the pressure in the storage tank 1 and the hydraulic pressure of the carbon dioxide in the storage tank 1. The carbon dioxide liquid enters the first injection tank 6 through the pipeline. (Since the pumping pressure of the injection pump 13 is greater than the pumping pressure of the infusion pump 15, the carbon dioxide liquid can only enter the first injection tank 6 and cannot enter the second injection tank 20.) The separation bag B25 in the first injection tank 6 is squeezed, and when the hydraulic pressure exceeds the opening pressure of the constant pressure opening valve B21, the pipeline opens, and the liquid in the separation bag B25 in the first injection tank 6 enters the balance tank 11 through the constant pressure opening valve A8 and the one-way valve C9.

[0026] The "process one" and "process two" of the present application work alternately. During the alternating working process, the injection pump 13 and the liquid replenishment pump 15 work continuously, thereby continuously injecting carbon dioxide liquid into the wellhead 18, and continuously injecting water into the storage tank 1. The pumping volume per unit time of the injection pump 13 and the liquid replenishment pump 15 is the same, so that the carbon dioxide outflow volume and the water replenishment volume in the storage tank 1 are the same, so that the storage tank 1 maintains a stable pressure state. It can be seen that the storage tank 1 of the present invention does not need to be replenished with gas multiple times to maintain stable air pressure, so there is no need to equip professional gas replenishment tools on site.

[0027] A balance tank 11 is arranged on the pipeline upstream of the branch port of the three-way reversing valve B14. The balance tank 11 is filled with liquid to ensure that there is liquid at the inlet end of the liquid replenishing pump 15 at the initial stage of operation, and there is no problem of dry pumping.

[0028] The upper end of the injection tank is connected with an exhaust pipe, and an exhaust valve 5 is installed on the exhaust pipe; the gas in the injection tank is discharged through the exhaust valve to ensure that there is no gas in the injection tank.

[0029] A flow sensor, a temperature sensor and a switch valve A10 are arranged on the pipeline upstream of the inlet end of the injection pump 13; a pressure sensor is arranged on the pipeline between the three-way reversing valve A12 and the two injection tanks; a flow sensor, a temperature sensor, a pressure sensor and a switch valve B23 are arranged on the pipeline between the replenishment pump 15 and the flange A3; a flow sensor, a temperature sensor, a pressure sensor and a switch valve C17 are arranged on the pipeline between the three-way reversing valve C16 and the wellhead 18. The required data can be obtained in real time through the flow sensor, the temperature sensor and the pressure sensor, so that the carbon dioxide injection situation is more clearly understood.

[0030] See attached Figure 2 The separation bag B25 passes through the hole in the center of the flange B7. A support sleeve 26 is provided in the central hole of the neck of the flange B7. The support sleeve 26 is located inside the separation bag B25 and is used to open the separation bag B25 from the inside and clamp the separation bag B25 between the flange and the support sleeve 26. A pressing sleeve 27 is provided in the central hole at the end of the flange B7. The pressing sleeve 27 is used to firmly press the end of the separation bag B25 on the flange B7. The pressing sleeve 27 and the support sleeve 26 are connected by threads. This ensures that the separation bag B25 can be fixed on the flange B7 and the seal is reliable.

[0031] In the present application, the partition bag A2 and the partition bag B25 are made of flexible corrosion-resistant and waterproof materials, such as rubber.

[0032] The present application discloses a special pump skid for increasing the production of carbon dioxide in oil and gas wells, which belongs to the technical field of carbon dioxide oil recovery and is one of the technical means for efficient oil field exploitation. The present invention adopts an injection system consisting of a skid-mounted base integrated storage tank 1, a double injection tank, an injection pump 13, a liquid replenishment pump 15 and a three-way reversing valve. A separation bag A2 is arranged inside the storage tank 1 to separate the space into liquid CO 2 Storage area and pressure regulation area, through the filling medium to achieve the pressure regulation of storage tank 1, avoid filling gaseous CO 2 problem, reducing CO 2 The dual injection tanks realize alternating working mode through three-way reversing valve A12 and three-way reversing valve B14: injection pump 13 pressurizes and injects CO into one injection tank through three-way valve A. 2 When the liquid replenishment pump 15 replenishes liquid CO to another injection tank through the three-way valve B, 2 , the three-way valve C realizes the continuous alternating supply of liquid from the two tanks to the wellhead 18. This structure enables liquid CO 2 The whole process does not contact with the injection pump 13, completely eliminating the air blockage phenomenon and ensuring the stability of pump efficiency. The original pressure compensation mechanism of the separation bag and the coordinated control of the three-way valve group achieve constant pressure in the storage tank 1 and continuous controllable injection flow, solving the pressure fluctuation and pumping interruption problems caused by phase change in traditional equipment, and significantly improving CO 2 Inject operational efficiency.

Claims

1. A special pump skid for increasing the production of carbon dioxide in an oil and gas well by increasing the pressure, comprising a base, on which an injection system is arranged, the injection system comprising a storage tank (1), an injection tank, an injection pump (13), a liquid replenishing pump (15), a three-way reversing valve A (12), a three-way reversing valve B (14) and a three-way reversing valve C (16); flanges A (3) are arranged at both ends of the storage tank (1), a separation bag A (2) is arranged in the storage tank (1), the two ends of the separation bag A (2) are fixedly connected to the flanges A (3), and a filling valve is arranged above the storage tank (1). The injection tank has two ports, namely, a first injection tank (6) and a second injection tank (20). Both ends of the injection tank are provided with flanges B (7). A separation bag B (25) is provided in the injection tank. Both ends of the separation bag B (25) are fixedly connected to the flanges B (7). The first injection tank (6) is connected to the storage tank (1) through a pipeline and a one-way valve A (4) is provided on the pipeline. The first injection tank (6) is also connected to a branch port of a three-way reversing valve C (16). The second injection tank (20) is connected to the storage tank (1) through a pipeline and the pipeline A one-way valve B (19) is arranged on the top, the second injection tank (20) is also connected to the branch port of the three-way reversing valve C (16), the main port of the three-way reversing valve C (16) is connected to the wellhead (18), the outlet end of the injection pump (13) is connected to the main port of the three-way reversing valve A (12), the two branch ports of the three-way reversing valve A (12) are respectively connected to one of the flanges B (7) of the first injection tank (6) and one of the flanges B (7) of the second injection tank (20), and the other flange B (7) of the first injection tank (6) is connected to the three-way reversing valve C (16) through a pipeline. The branch port of the valve B (14) is connected and a constant pressure opening valve A (8) and a non-return valve C (9) are arranged on the pipeline. The other flange B (7) of the second injection tank (20) is connected to the branch port of the three-way reversing valve B (14) through a pipeline and a constant pressure opening valve B (21) and a non-return valve D (22) are arranged on the pipeline. The main port of the three-way reversing valve B (14) is connected to the inlet end of the liquid replenishing pump (15). The outlet end of the liquid replenishing pump (15) is connected to one of the flanges A (3) of the storage tank (1) through a pipeline and a non-return valve E (24) is arranged on the pipeline.

2. A special pump skid for increasing the production of carbon dioxide and boosting the pressure of oil and gas wells according to claim 1, characterized in that: A balance tank (11) is provided on the pipeline upstream of the branch port of the three-way reversing valve B (14).

3. A special pump skid for increasing the production of carbon dioxide and boosting the pressure of oil and gas wells according to claim 1, characterized in that: The upper end of the injection tank is connected to an exhaust pipe, and an exhaust valve (5) is installed on the exhaust pipe.

4. A special pump skid for increasing the production of carbon dioxide and boosting the pressure of oil and gas wells according to claim 1, characterized in that: A flow sensor, a temperature sensor and a switch valve A (10) are arranged on the pipeline upstream of the inlet end of the injection pump (13); a pressure sensor is arranged on the pipeline between the three-way reversing valve A (12) and the two injection tanks; a flow sensor, a temperature sensor, a pressure sensor and a switch valve B (23) are arranged on the pipeline between the replenishing pump (15) and the flange A (3); and a flow sensor, a temperature sensor, a pressure sensor and a switch valve C (17) are arranged on the pipeline between the three-way reversing valve C (16) and the wellhead (18).

5. The special pump skid for increasing the production of carbon dioxide and boosting the pressure of oil and gas wells according to claim 1, characterized in that: The separation bag B (25) passes through the hole in the center of the flange B (7). A support sleeve (26) is provided in the center hole of the neck of the flange B (7). The support sleeve (26) is located inside the separation bag B (25) and is used to open the separation bag B (25) from the inside. A pressing sleeve (27) is provided in the center hole at the end of the flange B (7). The pressing sleeve (27) is used to firmly press the end of the separation bag B (25) onto the flange B (7). The pressing sleeve (27) and the support sleeve (26) are connected by threads.

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