Anti-backflow air foam driving gas-liquid mixing device

Abstract

The invention discloses an anti-backflow air foam driving gas-liquid mixing device which comprises a reducing pipe, the reducing pipe is connected with a throat pipe, the throat pipe is connected with a diverging pipe, and the diverging pipe is connected with a mixed liquid pipe; the throat pipe is further connected with a water inlet pipe, a pressure balance pipe is arranged between the water inlet pipe and the mixed liquid pipe, and the pressure balance pipe is provided with a check valve. According to the anti-backflow air foam flooding gas-liquid mixing device, high-pressure air injects low-pressure water to be fully mixed, and air foam flooding is generated under the action of a foaming agent to be used for oilfield exploitation. When oil well pressure fluctuates and rises, air foam can be prevented from entering the water inlet pipeline to cause water supply backflow, and the problems that liquid accumulates in the water inlet pipeline and the water inlet pipeline is prone to freezing due to cold in winter can be solved. The system is simple in structure, free of moving parts, safe and reliable, and has good application prospects in the petroleum field.

Description

Technical Field

[0001] The invention belongs to the technical field of air foam flooding equipment for petroleum exploitation, and in particular relates to an air foam flooding gas-liquid mixing device for preventing backflow. Background Art

[0002] In the process of oil production in oil fields, air foam flooding technology combines air flooding and foam flooding. It mixes high-pressure air with water and produces a gas-liquid two-phase mixture of air foam and water under the action of a foaming agent. It can improve the displacement efficiency and overcome the shortcomings of gas channeling in simple air flooding. It is suitable for oil reservoirs with a wide range of types, depths and ranges, especially for oil reservoirs with high water content, severe heterogeneity, cracks or large pores. It is one of the relatively cheap tertiary oil recovery methods with good development prospects.

[0003] At present, when air foam flooding is actually used for oil production, the pressure on the side of the oil well often fluctuates, which may cause the pressure of the liquid phase injection pipeline to be greater than the pressure of the gas phase pipeline, thereby causing air foam to enter the water inlet pipeline to form a backflow phenomenon, which will cause liquid to accumulate in the water inlet pipeline and be easily frozen in winter, affecting the mixing effect and safety of the air foam flooding gas and liquid. Summary of the invention

[0004] The purpose of the present invention is to provide an air foam drive gas-liquid mixing device with anti-backflow, which solves the problem in the prior art that during oil production, the pressure on the side of the oil well fluctuates, causing the pressure in the liquid phase pipeline to be greater than the pressure in the gas phase pipeline, thereby causing air foam to enter the water inlet pipeline and form a backflow.

[0005] The technical solution adopted by the present invention is an air foam drive gas-liquid mixing device for preventing backflow, comprising a convergent pipe, the convergent pipe is connected to a throat pipe, the throat pipe is connected to a divergent pipe, and the divergent pipe is connected to a mixed liquid pipe; the throat pipe is also connected to a water inlet pipe, a pressure balancing pipe is provided between the water inlet pipe and the mixed liquid pipe, and the pressure balancing pipe is provided with a check valve.

[0006] The present invention is also characterized in that:

[0007] The longitudinal section of the reducer is trapezoidal. The reducer comprises a first reducer interface and a second reducer interface. The second reducer interface is connected to the throat tube, and the first reducer interface is connected to the intake pipe.

[0008] The longitudinal section of the gradually expanding pipe is trapezoidal. The gradually expanding pipe comprises a first gradually expanding pipe interface and a second gradually expanding pipe interface. The first gradually expanding pipe interface is connected to the throat pipe, and the second gradually expanding pipe interface is connected to the mixed liquid pipe.

[0009] The pressure balance pipe is equipped with a pressure gauge.

[0010] The water inlet pipe is provided with a first valve, and the first valve is arranged between the pressure balance pipe and the injection station.

[0011] The water inlet pipe is provided with a second valve, and the second valve is provided between the pressure balance pipe and the throat pipe.

[0012] The first valve and the second valve are opened and closed at the same time.

[0013] The beneficial effects of the present invention are as follows: the air-foam flooding gas-liquid mixing device for preventing backflow of the present invention uses high-pressure air to inject low-pressure water for full mixing, and generates air-foam flooding for oil field exploitation under the action of a foaming agent. When the pressure of the oil well fluctuates and rises, the air-foam flooding can be prevented from entering the water inlet pipeline to cause water backflow, and the problems of liquid accumulation in the water inlet pipeline and easy freezing in winter can be overcome. The system has a simple structure, no moving parts, is safe and reliable, and has good application prospects in the field of oil. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a structural schematic diagram of the air-foam-driven gas-liquid mixing device for preventing backflow of the present invention.

[0015] In the figure, 1. air inlet pipe, 2. water inlet pipe, 3. convergent pipe, 4. throat pipe, 5. divergent pipe, 6. mixed liquid pipe, 7. pressure balance pipe, 8. check valve, 9. pressure gauge, 10. first valve, 11. second valve, 12. first interface of the convergent pipe, 13. second interface of the convergent pipe, 14. first interface of the divergent pipe, 15. second interface of the divergent pipe. DETAILED DESCRIPTION

[0016] The specific implementation modes of the present invention are described in detail below with reference to the accompanying drawings.

[0017] The air foam drive gas-liquid mixing device for preventing backflow provided by the present invention is as follows: Figure 1As shown, it includes a converging pipe 3, which is connected to a throat pipe 4, which is connected to a gradually expanding pipe 5, which is connected to a mixed liquid pipe 6, so that air can enter from the converging pipe 3, the throat pipe 4 and the gradually expanding pipe 5; the throat pipe 4 is also connected to a water inlet pipe 2, so that water can enter, and a pressure balance pipe 7 is provided between the water inlet pipe 2 and the mixed liquid pipe 6, and a check valve 8 is provided in the pressure balance pipe 7. The converging pipe 3 has a trapezoidal longitudinal section, and the converging pipe 3 includes a first converging pipe interface 12 and a second converging pipe interface 13, which is connected to the throat pipe 4, and the first converging pipe interface 12 is connected to the air inlet pipe 1. When air enters from the air inlet pipe 1, the air pressure increases due to the different cross-sectional shapes of the converging pipe 3. The gradually expanding pipe 5 has a trapezoidal longitudinal section, and the gradually expanding pipe 5 includes a first converging pipe interface 14 and a second converging pipe interface 15, which is connected to the throat pipe 4, and the second converging pipe interface 15 is connected to the mixed liquid pipe 6. The pressure balance pipe 7 is provided with a pressure gauge 9, which is convenient for measuring the liquid pressure in the pressure balance pipe 7. The water inlet pipe 2 is provided with a first valve 10, which is arranged between the pressure balance pipe 7 and the injection station, so as to control the water source entering. The water inlet pipe 2 is provided with a second valve 11, which is arranged between the pressure balance pipe 7 and the throat pipe 4. The first valve 10 and the second valve 11 are opened and closed at the same time to prevent the air bubbles in the throat pipe 4 from flowing back through the water inlet pipe 2.

[0018] The air-foam flooding gas-liquid mixing device for preventing backflow of the present invention has the following working principle: when the oil well is normally exploited, high-pressure air enters the tapered pipe 3 and the throat pipe 4 through the air inlet pipe 1, generating a front-rear pressure difference, thereby drawing low-pressure water into the throat pipe 4 for mixing and forming air foam flooding under the action of a foaming agent, and then transporting the water to the oil well through the mixed liquid pipe 6 for oil recovery; when the pressure of the oil well fluctuates and increases, part of the gas phase working fluid in the mixed liquid pipe 6 enters the water inlet pipe 2 through the pressure balance pipe 7 and the check valve 8, thereby increasing the water side pressure and forming an air sealing effect, thereby preventing the air foam in the throat pipe 4 from flowing back through the water inlet pipe 2.

[0019] Example 1

[0020] The air foam flooding gas-liquid mixing device for preventing backflow proposed in this embodiment is as follows: Figure 1 As shown, it includes a convergent pipe 3, the convergent pipe 3 is connected to a throat pipe 4, the throat pipe 4 is connected to a divergent pipe 5, and the divergent pipe 5 is connected to a mixed liquid pipe 6; the throat pipe 4 is also connected to a water inlet pipe 2, a pressure balance pipe 7 is provided between the water inlet pipe 2 and the mixed liquid pipe 6, and the pressure balance pipe 7 is provided with a check valve 8.

[0021] Example 2

[0022] The air foam flooding gas-liquid mixing device for preventing backflow proposed in this embodiment is as follows: Figure 1As shown, it includes a convergent pipe 3, the convergent pipe 3 is connected to a throat pipe 4, the throat pipe 4 is connected to a divergent pipe 5, and the divergent pipe 5 is connected to a mixed liquid pipe 6; the throat pipe 4 is also connected to a water inlet pipe 2, a pressure balance pipe 7 is provided between the water inlet pipe 2 and the mixed liquid pipe 6, and the pressure balance pipe 7 is provided with a check valve 8.

[0023] The longitudinal section of the reducer 3 is trapezoidal. The reducer 3 includes a first reducer interface 12 and a second reducer interface 13 . The second reducer interface 13 is connected to the throat pipe 4 . The first reducer interface 12 is connected to the intake pipe 1 .

[0024] The longitudinal section of the gradually expanding pipe 5 is trapezoidal. The gradually expanding pipe 5 includes a first gradually expanding pipe interface 14 and a second gradually expanding pipe interface 15 . The first gradually expanding pipe interface 14 is connected to the throat pipe 4 , and the second gradually expanding pipe interface 15 is connected to the mixed liquid pipe 6 .

[0025] Example 3

[0026] The air foam flooding gas-liquid mixing device for preventing backflow proposed in this embodiment is as follows: Figure 1 As shown, it includes a convergent pipe 3, the convergent pipe 3 is connected to a throat pipe 4, the throat pipe 4 is connected to a divergent pipe 5, and the divergent pipe 5 is connected to a mixed liquid pipe 6; the throat pipe 4 is also connected to a water inlet pipe 2, a pressure balance pipe 7 is provided between the water inlet pipe 2 and the mixed liquid pipe 6, and the pressure balance pipe 7 is provided with a check valve 8.

[0027] The longitudinal section of the reducer 3 is trapezoidal. The reducer 3 includes a first reducer interface 12 and a second reducer interface 13 . The second reducer interface 13 is connected to the throat pipe 4 . The first reducer interface 12 is connected to the intake pipe 1 .

[0028] The longitudinal section of the gradually expanding pipe 5 is trapezoidal. The gradually expanding pipe 5 includes a first gradually expanding pipe interface 14 and a second gradually expanding pipe interface 15 . The first gradually expanding pipe interface 14 is connected to the throat pipe 4 , and the second gradually expanding pipe interface 15 is connected to the mixed liquid pipe 6 .

[0029] The pressure balance pipe 7 is provided with a pressure gauge 9.

[0030] The water inlet pipe 2 is provided with a first valve 10, and the first valve 10 is arranged between the pressure balance pipe 7 and the injection station.

[0031] Example 4

[0032] The air foam flooding gas-liquid mixing device for preventing backflow proposed in this embodiment is as follows: Figure 1 As shown, it includes a convergent pipe 3, the convergent pipe 3 is connected to a throat pipe 4, the throat pipe 4 is connected to a divergent pipe 5, and the divergent pipe 5 is connected to a mixed liquid pipe 6; the throat pipe 4 is also connected to a water inlet pipe 2, a pressure balance pipe 7 is provided between the water inlet pipe 2 and the mixed liquid pipe 6, and the pressure balance pipe 7 is provided with a check valve 8.

[0033] The longitudinal section of the reducer 3 is trapezoidal. The reducer 3 includes a first reducer interface 12 and a second reducer interface 13 . The second reducer interface 13 is connected to the throat pipe 4 . The first reducer interface 12 is connected to the intake pipe 1 .

[0034] The longitudinal section of the gradually expanding pipe 5 is trapezoidal. The gradually expanding pipe 5 includes a first gradually expanding pipe interface 14 and a second gradually expanding pipe interface 15 . The first gradually expanding pipe interface 14 is connected to the throat pipe 4 , and the second gradually expanding pipe interface 15 is connected to the mixed liquid pipe 6 .

[0035] The pressure balance pipe 7 is provided with a pressure gauge 9.

[0036] The water inlet pipe 2 is provided with a first valve 10, and the first valve 10 is arranged between the pressure balance pipe 7 and the injection station.

[0037] The water inlet pipe 2 is provided with a second valve 11 , and the second valve 11 is provided between the pressure balance pipe 7 and the throat pipe 4 .

[0038] The first valve 10 and the second valve 11 are opened and closed at the same time.

Claims

1. Anti-backflow air foam drive gas-liquid mixing device, characterized in that: The invention comprises a gradually contracting pipe (3), wherein the gradually contracting pipe (3) is connected to a throat pipe (4), wherein the throat pipe (4) is connected to a gradually expanding pipe (5), and wherein the gradually expanding pipe (5) is connected to a mixed liquid pipe (6); the throat pipe (4) is also connected to a water inlet pipe (2), a pressure balancing pipe (7) is provided between the water inlet pipe (2) and the mixed liquid pipe (6), and the pressure balancing pipe (7) is provided with a check valve (8).

2. The air-foam-driven gas-liquid mixing device for preventing backflow according to claim 1, characterized in that: The longitudinal section of the reducer (3) is trapezoidal. The reducer (3) comprises a first reducer interface (12) and a second reducer interface (13). The second reducer interface (13) is connected to the throat tube (4). The first reducer interface (12) is connected to the intake pipe (1).

3. The air-foam-driven gas-liquid mixing device for preventing backflow according to claim 1, characterized in that: The longitudinal section of the gradually expanding pipe (5) is trapezoidal. The gradually expanding pipe (5) comprises a first gradually expanding pipe interface (14) and a second gradually expanding pipe interface (15). The first gradually expanding pipe interface (14) is connected to the throat pipe (4), and the second gradually expanding pipe interface (15) is connected to the mixed liquid pipe (6).

4. The air-foam-driven gas-liquid mixing device for preventing backflow according to claim 1, characterized in that: The pressure balance pipe (7) is provided with a pressure gauge (9).

5. The air-foam-driven gas-liquid mixing device for preventing backflow according to claim 1, characterized in that: The water inlet pipe (2) is provided with a first valve (10), and the first valve (10) is arranged between the pressure balance pipe (7) and the injection station.

6. The air-foam-driven gas-liquid mixing device for preventing backflow according to claim 5, characterized in that: The water inlet pipe (2) is provided with a second valve (11), and the second valve (11) is provided between the pressure balance pipe (7) and the throat pipe (4).

7. The air-foam-driven gas-liquid mixing device for preventing backflow according to claim 6, characterized in that: The first valve (10) and the second valve (11) are opened and closed at the same time.

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