An oxygen-reduced air foam composite flooding efficient injection process device

Abstract

The utility model belongs to a kind of oxygen-reducing air foam composite drive efficient injection process device, including liquid injection system and oxygen-reducing air injection system connected with injection well;Wherein, liquid injection system includes gel injection system and foam liquid injection system, gel injection system and foam liquid injection system share same liquid preparation device and liquid injection device;Gel injection system includes polymer solution injection system, crosslinking agent solution injection system and water injection system.The utility model is through gel plugging injection process and air oxygen-reducing process, on the one hand, effectively expand the swept volume of foam drive, improve oil recovery, on the other hand, reduce the oxygen content of injected air, reduce the risk of oil well oxidation corrosion and associated gas explosion risk;More preferably, through metering device, computer and solenoid valve group realize safe, efficient, accurate injection operation, with low labor intensity, operability and easy maintenance and other advantages.

Description

Technical Field

[0001] This utility model belongs to the technical field of foam flooding to enhance oil recovery during oilfield development, and specifically relates to a high-efficiency injection process device for oxygen-reduced air foam composite flooding. Background Technology

[0002] For the problem of rapid water cut increase in oil wells during the mid-to-late stages of water injection development in oilfields, air foam flooding can, to some extent, block the dominant seepage channels of water flooding, expand the swept volume, and improve oil displacement efficiency. However, for highly heterogeneous reservoirs with well-developed fractures, the foam's plugging ability is limited, thus its water control and oil production increase are very limited. In addition, the air released after the foam bursts can easily flow into the production wells along fractures and other large pores, posing a risk of explosion when the associated gas oxygen content in the production wells reaches a certain proportion.

[0003] This invention addresses the issues of high safety risks and insufficient oil displacement effects associated with single-air foam flooding in reservoirs with well-developed fractures and significant heterogeneity. By incorporating gel plugging injection and source oxygen reduction processes, it effectively expands the swept volume of foam flooding, improving oil recovery, while simultaneously reducing the oxygen content of the injected gas at the source, thus mitigating the risks of well oxidation and corrosion, as well as associated gas explosions. Furthermore, the process equipment, through electrical automation and computer program control, achieves safe, efficient, and precise injection operations, offering advantages such as low labor intensity, high operability, and ease of maintenance. Summary of the Invention

[0004] The present invention aims to provide an efficient injection process device for oxygen-reduced air foam composite flooding, which solves the problems of unsatisfactory air foam flooding effect and high safety risks in fractured reservoirs.

[0005] The technical solution of this utility model is as follows: An efficient injection process device for oxygen-reduced air foam composite flooding includes a liquid injection system and an oxygen-reduced air injection system connected to an injection well; the liquid injection system includes a gel injection system and a foam liquid injection system, and the gel injection system includes a polymer solution injection system, a crosslinking agent solution injection system and a water injection system.

[0006] The inlet ends of the foam liquid injection system, polymer solution injection system, and crosslinking agent solution injection system are each connected to the same liquid preparation device, and the outlet ends of the foam liquid injection system, polymer solution injection system, crosslinking agent solution injection system, and water injection system are each connected to the same liquid injection device.

[0007] The solution preparation device includes a water injection pipeline and a mixing tank connected in sequence, and also includes a dosing device connected to the mixing tank.

[0008] The liquid injection system includes a foam liquid storage tank, a polymer solution storage tank, a crosslinking agent solution storage tank, and a water storage tank arranged in parallel; wherein the inlet pipelines of the foam liquid storage tank, the polymer solution storage tank, and the crosslinking agent solution storage tank are all connected to the mixing tank through a common feeding pump.

[0009] The injection device includes a filter, an injection pump, and a liquid mixer connected in sequence through injection pipelines. The inlet end of the filter is connected to the outlet pipelines of the foam liquid storage tank, the polymer solution storage tank, the crosslinking agent solution storage tank, and the water storage tank, respectively. The outlet end of the liquid mixer is connected to each injection well, respectively.

[0010] The oxygen-reduced air injection system includes a gas collection device, a deoxygenation device, a gas compressor, and a gas distributor connected in sequence through an oxygen-reduced air injection pipeline. The outlet end of the gas distributor is connected to each injection well.

[0011] It also includes metering devices and a computer; the metering devices include a liquid flow meter at the water injection end located on the water injection pipeline, a liquid flow meter and liquid pressure sensor at the injection end on the injection pipeline between the liquid distributor and the injection well, and a gas flow meter and gas pressure sensor on the oxygen-reducing air injection pipeline; wherein, the liquid flow meter at the water injection end, the liquid flow meter at the injection end, the liquid pressure sensor, the gas flow meter, and the gas pressure sensor are all connected to the computer.

[0012] It also includes a solenoid valve assembly connected to a computer, comprising a first solenoid valve on the water injection pipeline, a second solenoid valve on the inlet pipeline of the foam liquid storage tank, a third solenoid valve on the inlet pipeline of the polymer solution storage tank, a fourth solenoid valve on the inlet pipeline of the crosslinking agent solution storage tank, a fifth solenoid valve on the outlet pipeline of the foam liquid storage tank, a sixth solenoid valve on the outlet pipeline of the polymer solution storage tank, a seventh solenoid valve on the outlet pipeline of the crosslinking agent solution storage tank, an eighth solenoid valve on the outlet pipeline of the water storage tank, a liquid phase solenoid valve on the injection pipeline between the liquid dispenser and the injection well, and a gas phase solenoid valve on the oxygen-reducing air injection pipeline.

[0013] The interior of the mixing tank, foam liquid storage tank, polymer solution storage tank, and crosslinking agent solution storage tank is equipped with an anti-corrosion coating.

[0014] The deoxygenation device is a membrane separation deoxygenation device, the gas collection device is a dry screw pump, the common feeding pump is a centrifugal pump, and the injection pump is a reciprocating plunger pump.

[0015] The technical advantages of this utility model are as follows: This invention utilizes a gel-sealing injection process and an air deoxygenation process to effectively expand the swept volume of foam flooding and improve oil recovery. On the other hand, it reduces the oxygen content of the injected air, thereby reducing the risk of oil well oxidation and corrosion, as well as the risk of associated gas explosion. More preferably, it achieves safe, efficient, and precise injection operations through a metering device, computer, and solenoid valve assembly, which has the advantages of low labor intensity, high operability, and easy maintenance. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the device of this utility model.

[0017] Attached reference numerals: 1. Water injection pipeline; 2-1. First solenoid valve; 2-2. Second solenoid valve; 2-3. Third solenoid valve; 2-4. Fourth solenoid valve; 2-5. Fifth solenoid valve; 2-6. Sixth solenoid valve; 2-7. Seventh solenoid valve; 2-8. Eighth solenoid valve; 2-9. Liquid phase solenoid valve; 2-11. Gas phase solenoid valve; 3-1. Liquid phase flow meter at the water injection end; 3-2. Liquid phase flow meter at the injection end; 4. Dosing device; 5. Mixing tank; 6. Common feeding pump; 7-1. Foam solution storage tank; 7-2. Polymer solution storage tank; 7-3. Crosslinking agent solution storage tank; 7-4. Water storage tank; 8. Filter; 9. Injection pump; 10. Liquid mixer; 11-1 Liquid phase pressure sensor; 11-4 Gas phase pressure sensor; 12 Injection well; 13 Gas phase flow meter; 14 Gas distributor; 15 Gas compressor; 16 Deoxygenation device; 17 Gas capture device. Detailed Implementation

[0018] Example 1 An efficient injection process device for oxygen-reduced air foam composite flooding includes a liquid injection system and an oxygen-reduced air injection system connected to an injection well 12; the liquid injection system includes a gel injection system and a foam liquid injection system, and the gel injection system includes a polymer solution injection system, a crosslinking agent solution injection system and a water injection system.

[0019] The specific implementation process of this embodiment is as follows: Polymer solution and crosslinking agent solution are injected sequentially into injection well 12; after the crosslinking agent solution is injected, a certain amount of water is injected into injection well 12 through the water injection system to replace the polymer solution and crosslinking agent solution in the deep part of the reservoir to form a gel and seal the large pores of the reservoir. After the gel injection system is completed, foam liquid is injected into injection well 12 through the foam liquid injection system; After the foam liquid injection is complete, turn off the liquid injection system; Adjust the gas injection volume of injection well 12 through the deoxygenated air injection system and inject deoxygenated air into injection well 12; Subsequently, foam liquid and deoxygenated air are injected alternately in a cycle to form deoxygenated air foam flooding in the reservoir.

[0020] Example 2 Based on Example 1, the system further includes the following: the inlet ends of the foam liquid injection system, the polymer solution injection system, and the crosslinking agent solution injection system are respectively connected to the same liquid preparation device, and the outlet ends of the foam liquid injection system, the polymer solution injection system, the crosslinking agent solution injection system, and the water injection system are respectively connected to the same liquid injection device.

[0021] The liquid preparation device includes a water injection pipeline 1 and a mixing tank 5 connected in sequence, and also includes a dosing device 4 connected to the mixing tank 5.

[0022] The liquid injection system includes a foam liquid storage tank 7-1, a polymer solution storage tank 7-2, a crosslinking agent solution storage tank 7-3, and a water storage tank 7-4 arranged in parallel; wherein, the inlet pipelines of the foam liquid storage tank 7-1, the polymer solution storage tank 7-2, and the crosslinking agent solution storage tank 7-3 are all connected to the stirring tank 5 through a common feeding pump 6.

[0023] The injection device includes a filter 8, an injection pump 9, and a liquid mixer 10 connected in sequence through injection pipelines. The inlet end of the filter 8 is connected to the outlet pipelines of the foam liquid storage tank 7-1, the polymer solution storage tank 7-2, the crosslinking agent solution storage tank 7-3, and the water storage tank 7-4, respectively. The outlet end of the liquid mixer 10 is connected to each injection well 12, respectively.

[0024] The deoxygenated air injection system includes a gas collection device 17, a deoxygenation device 16, a gas compressor 15, and a gas distributor 14 connected in sequence through a deoxygenated air injection pipeline. The outlet end of the gas distributor 14 is connected to each injection well 12.

[0025] Example 3 Based on Embodiment 2, a metering device and a computer are also included; the metering device includes a liquid flow meter 3-1 at the water injection end located on the water injection pipeline 1, a liquid flow meter 3-2 at the injection end and a liquid pressure sensor 11-1 at the injection end on the injection pipeline between the liquid distributor 10 and the injection well 12, and a gas flow meter 13 and a gas pressure sensor 11-4 at the oxygen-reduced air injection pipeline; wherein, the liquid flow meter 3-1 at the water injection end, the liquid flow meter 3-2 at the injection end, the liquid pressure sensor 11-1, the gas flow meter 13, and the gas pressure sensor 11-4 are all connected to the computer.

[0026] It also includes a solenoid valve assembly connected to a computer, which includes a first solenoid valve 2-1 located on the water injection pipeline 1, a second solenoid valve 2-2 located on the inlet pipeline of the foam liquid storage tank 7-1, a third solenoid valve 2-3 located on the inlet pipeline of the polymer solution storage tank 7-2, a fourth solenoid valve 2-4 located on the inlet pipeline of the crosslinking agent solution storage tank 7-3, a fifth solenoid valve 2-5 located on the outlet pipeline of the foam liquid storage tank 7-1, a sixth solenoid valve 2-6 located on the outlet pipeline of the polymer solution storage tank 7-2, a seventh solenoid valve 2-7 located on the outlet pipeline of the crosslinking agent solution storage tank 7-3, an eighth solenoid valve 2-8 located on the outlet pipeline of the water storage tank 7-4, a liquid phase solenoid valve 2-9 located on the injection pipeline between the liquid dispenser 10 and the injection well 12, and a gas phase solenoid valve 2-11 located on the oxygen-reduced air injection pipeline.

[0027] Example 4 Based on Example 3, the interiors of the mixing tank 5, foam liquid storage tank 7-1, polymer solution storage tank 7-2, and crosslinking agent solution storage tank 7-3 are all coated with anti-corrosion coatings. The deoxygenation device 16 is a membrane separation deoxygenation device, the gas collection device 17 is a dry screw pump, the common feed pump 6 is a centrifugal pump, and the injection pump 9 is a reciprocating plunger pump.

[0028] The specific implementation process of this embodiment is as follows: First, according to the water flow rate of the water injection pipeline 1, the polymer is added to the mixing tank 5 through the dosing device 4 to prepare the target polymer solution. Then, it is pumped into the polymer solution storage tank 7-2 through the feeding pump 6. After being filtered by the filter 8, it is pressurized and injected into each injection well 12 through the injection pump 9. The injection volume of the target polymer solution in each injection well 12 is controlled by the liquid distributor 10 according to the reservoir engineering design parameters. After the target polymer solution is injected, the stirring tank 5 is cleaned and the target crosslinking agent solution is prepared in the stirring tank 5. Then, it is pumped into the crosslinking agent solution storage tank 7-3 through the feeding pump 6. After being filtered by the filter 8, it is pressurized and injected into each injection well 12 through the injection pump 9. The injection volume of the target crosslinking agent solution in each injection well 12 is controlled by the liquid distributor 10 according to the reservoir engineering design parameters. After the target crosslinking agent solution is injected, a certain amount of water is injected into each injection well 12 through the water storage tank 7-4, filter 8 and injection pump 9 in sequence. This displaces the target polymer solution and target crosslinking agent solution into the deep reservoir to form a gel and seal the reservoir's large pores.

[0029] After the gel system is injected, the mixing tank 5 is cleaned and the target foam liquid is prepared in the mixing tank 5. Then, it is pumped into the foam liquid storage tank 7-1 through the feeding pump 6. After being filtered by the filter 8, it is pressurized and injected into each injection well 12 through the injection pump 9. The injection volume of the target foam liquid in each injection well 12 is controlled by the liquid distributor 10 according to the reservoir engineering design parameters. After the foam liquid injection is complete, turn off the liquid injection system; The deoxygenated air injection system is activated. Air passes through the gas collection device 17 and the deoxygenation device 16 in sequence to form deoxygenated air. After being compressed by the gas compressor 15, the deoxygenated air is injected into the injection well 12 after the gas distribution device 14 regulates the injection volume. Subsequently, foam liquid and deoxygenated air are injected alternately in a cycle to form deoxygenated air foam flooding in the reservoir.

[0030] In addition, the liquid flow meter 3-1 at the water injection end, the liquid flow meter 3-2 at the injection end, the liquid pressure sensor 11-1, the gas flow meter 13, and the gas pressure sensor 11-4 measure the injection parameters online and transmit them to the computer for storage. The computer controls the opening and closing of each solenoid valve in the solenoid valve group according to the experimental requirements.

Claims

1. A high-efficiency injection process device for oxygen-reducing air foam composite drive, characterized in that, This includes a liquid injection system and an oxygen-reducing air injection system connected to the injection well (12); Liquid injection systems include gel injection systems and foam liquid injection systems. Gel injection systems include polymer solution injection systems, crosslinking agent solution injection systems, and water injection systems. The inlet ends of the foam liquid injection system, polymer solution injection system and crosslinking agent solution injection system are respectively connected to the same liquid preparation device, and the outlet ends of the foam liquid injection system, polymer solution injection system and crosslinking agent solution injection system and water injection system are respectively connected to the same liquid injection device. The liquid preparation device includes a water injection pipeline (1) and a mixing tank (5) connected in sequence, and also includes a dosing device (4) connected to the mixing tank (5); The liquid injection system includes a foam liquid storage tank (7-1), a polymer solution storage tank (7-2), a crosslinking agent solution storage tank (7-3), and a water storage tank (7-4) arranged in parallel; wherein, the inlet pipelines of the foam liquid storage tank (7-1), the polymer solution storage tank (7-2), and the crosslinking agent solution storage tank (7-3) are all connected to the stirring tank (5) through a common feeding pump (6); The deoxygenated air injection system includes a gas collection device (17), a deoxygenation device (16), a gas compressor (15), and a gas distributor (14) connected in sequence through a deoxygenated air injection pipeline. The outlet end of the gas distributor (14) is connected to each injection well (12).

2. The high-efficiency injection process device for oxygen-reducing air foam composite displacement according to claim 1, characterized in that, The injection device includes a filter (8), an injection pump (9), and a liquid mixer (10) connected in sequence through injection pipelines. The inlet end of the filter (8) is connected to the outlet pipelines of the foam liquid storage tank (7-1), the polymer solution storage tank (7-2), the crosslinking agent solution storage tank (7-3), and the water storage tank (7-4), respectively. The outlet end of the liquid mixer (10) is connected to each injection well (12).

3. The high-efficiency injection process device for oxygen-reducing air foam composite displacement according to claim 2, characterized in that, It also includes a metering device and a computer; the metering device includes a liquid flow meter (3-1) at the water injection end on the water injection pipeline (1), a liquid flow meter (3-2) at the injection end and a liquid pressure sensor (11-1) at the injection end on the injection pipeline between the liquid distributor (10) and the injection well (12), and a gas flow meter (13) and a gas pressure sensor (11-4) at the oxygen-reducing air injection pipeline; wherein, the liquid flow meter (3-1) at the water injection end, the liquid flow meter (3-2) at the injection end, the liquid pressure sensor (11-1), the gas flow meter (13) and the gas pressure sensor (11-4) are all connected to the computer.

4. The high-efficiency injection process device for oxygen-reducing air foam composite displacement according to claim 3, characterized in that, It also includes a solenoid valve assembly connected to a computer, which includes a first solenoid valve (2-1) on the water injection line (1), a second solenoid valve (2-2) on the inlet line of the foam liquid storage tank (7-1), a third solenoid valve (2-3) on the inlet line of the polymer solution storage tank (7-2), a fourth solenoid valve (2-4) on the inlet line of the crosslinking agent solution storage tank (7-3), a fifth solenoid valve (2-5) on the outlet line of the foam liquid storage tank (7-1), a sixth solenoid valve (2-6) on the outlet line of the polymer solution storage tank (7-2), a seventh solenoid valve (2-7) on the outlet line of the crosslinking agent solution storage tank (7-3), an eighth solenoid valve (2-8) on the outlet line of the water storage tank (7-4), a liquid phase solenoid valve (2-9) on the injection line between the liquid dispenser (10) and the injection well (12), and a gas phase solenoid valve (2-11) on the oxygen-reduced air injection line.

5. The high-efficiency injection process device for oxygen-reducing air foam composite displacement according to claim 4, characterized in that, The interior of the mixing tank (5), foam liquid storage tank (7-1), polymer solution storage tank (7-2), and crosslinking agent solution storage tank (7-3) is all provided with an anti-corrosion coating.

6. The high-efficiency injection process device for oxygen-reducing air foam composite displacement according to claim 1, characterized in that, The deoxygenation device (16) is a membrane separation deoxygenation device, the gas collection device (17) is a dry screw pump, the common feeding pump (6) is a centrifugal pump, and the injection pump (9) is a reciprocating plunger pump.

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