An oil-gas mixing and transportation device and oil-gas transportation system suitable for high gas-oil ratio conditions

Abstract

This utility model relates to an oil-gas mixed transportation device and system suitable for high gas-oil ratio conditions. It includes a slug trap, at least one buffer tank, and a compressor. The drain port of the slug trap is connected to the inlet of the buffer tank via a valve. The exhaust port of the slug trap is connected to the inlet of the compressor via a valve. The exhaust port of the compressor is connected to the inlet of the buffer tank via a valve. Both the exhaust port of the compressor and the drain port of the buffer tank are connected to an external transportation pipeline via valves. This invention uses a compressor to pressurize the gas phase in the produced fluid after gas-liquid separation, and then uses the gas phase to drive the liquid phase for transportation. This avoids the problem of pressurization failure in high-gas-content produced fluids in traditional oil-gas mixed transportation devices, achieving closed-loop oil-gas transportation and solving the problems in the background art. It achieves high-efficiency transportation requirements, adapts to different displacements and arbitrarily high gas-oil ratio conditions, and has strong adaptability to gas-liquid ratio fluctuations in oil products from different blocks and development stages. It also has strong adaptability to sand-bearing crude oil and slug flows generated during mixed transportation.

Description

Technical Field

[0001] This utility model belongs to the field of complex oil and gas transportation technology in oilfields, and particularly relates to an oil and gas mixed transportation device and oil and gas transportation system suitable for high gas-oil ratio conditions. Background Technology

[0002] In the development of domestic oilfields, oil and gas gathering and transportation typically employ either oil and gas separation or oil and gas mixed transportation processes. While oil and gas separation processes are mature and reliable, they involve numerous pieces of equipment, high construction investment, high operating costs, and significant safety management risks. In contrast, oil and gas mixed transportation processes allow for unmanned wellhead operations, reducing construction investment and the safety risks associated with personnel on-site, and are widely used in oilfields.

[0003] As a key piece of equipment in the oil and gas co-transport process, the oil and gas co-transport unit is responsible for pressurizing and transporting produced fluids from oil wells. Because produced fluids are multiphase mixtures containing oil, gas, water, and various impurities, the proportions of oil, gas, and water vary in different oilfields and blocks, and the physical properties of the oil also differ. Furthermore, the presence of slug flow during oil and gas co-transport limits the adaptability of the co-transport pressurization unit, especially for produced fluids with an excessively high gas volume fraction; currently, existing products in this field cannot effectively solve the co-transport problem. For example: 1. Dual-chamber mixing devices employ a dual-chamber design, using a power pump to alternately pressurize the liquid within each chamber. The drawback is that, limited by chamber capacity, they can only handle relatively small displacements. 2. Liquid-driven mixing devices achieve oil-gas mixing through liquid-phase pressurization. The drawback is that when the gas content is high, the internal fluid flow becomes complex, affecting both the suction and discharge performance of the device. 3. Glue-coated twin-screw mixing pumps achieve uniform mixing and delivery of the oil-gas mixture through screw rotation and changes in the sealed chamber. The drawback is poor adaptability to slug flow, and severe pump wear at high gas content. 4. Rotary impeller pumps achieve continuous mixing through impeller motion. The drawbacks are a low pressure ratio, limited displacement capacity, and suitability only for media with low gas-liquid ratios.

[0004] In summary, currently known technologies and processes cannot solve the problems existing in high gas-liquid ratio oil-gas mixed transportation conditions. To meet the requirements of efficient oil and gas gathering and transportation, solve the failure problem of traditional oil-gas mixed transportation devices under high gas-oil ratio conditions, and optimize the process flow, a new oil-gas mixed transportation process and device suitable for high gas-oil ratio conditions is proposed. Utility Model Content

[0005] The technical problem to be solved by this utility model is to propose an oil-gas mixed transportation device that can achieve high-efficiency transportation requirements and is suitable for high gas-oil ratio conditions, in order to address the shortcomings of the existing technology.

[0006] This utility model is achieved using the following solution: An oil-gas mixed transportation device suitable for high gas-oil ratio conditions is characterized by comprising a slug trap, at least one buffer tank, and a compressor. The drain port of the slug trap is connected to the inlet of the buffer tank via a valve. The exhaust port of the slug trap is connected to the air inlet of the compressor via a valve. The exhaust port of the compressor is connected to the air inlet of the buffer tank via a valve. Both the exhaust port of the compressor and the drain port of the buffer tank are connected to an external transportation pipeline via valves.

[0007] According to the above technical solution, at least two buffer tanks are provided, which are arranged side by side. The liquid inlet of each buffer tank is connected to the liquid outlet of the slug trap, the air inlet of each buffer tank is connected to the exhaust port of the compressor, and the liquid outlet of each buffer tank is connected to an external delivery pipeline.

[0008] According to the above technical solution, it also includes a skid, and the slug catcher, buffer tank and compressor are all mounted on the skid.

[0009] According to the above technical solution, the compressor includes a frequency converter, a compressor main unit, an explosion-proof motor, a buffer tank, a cooler, and a lubricating oil system.

[0010] According to the above technical solution, a throttling valve is installed on the external discharge pipeline of the compressor.

[0011] According to the above technical solution, the exhaust port and the liquid discharge port of the slug trap are both equipped with pressure transmitters, and the inlet port and the exhaust port of the compressor are both equipped with pressure transmitters.

[0012] According to the above technical solution, the buffer tank is equipped with a pressure transmitter and a level transmitter.

[0013] According to the above technical solution, the bottom of the slug flow trap is provided with a sand removal port, the bottom of the buffer tank is provided with a drain port, and the bottom of the compressor is provided with a drain pipeline.

[0014] According to the above technical solution, the bottom of the slug trap, the buffer tank, and the compressor are all fixedly connected to a support frame, and the bottom of the support frame is fixedly connected to the skid.

[0015] According to the above technical solution, the control cabinet is fixed at the edge of the skid.

[0016] An oil and gas transportation system, characterized in that it includes an oil and gas mixed transportation device as described above, suitable for high gas-oil ratio conditions.

[0017] The beneficial effects of this utility model are as follows: 1. This utility model provides an oil-gas mixed transportation device suitable for high oil-gas ratio. After gas-liquid separation, the gas phase in the produced fluid is pressurized by a compressor, and the gas phase drives the liquid phase for transportation. This avoids the problem of pressurization failure of traditional oil-gas mixed transportation devices for high gas content produced fluid, and realizes closed-loop oil-gas transportation, thereby solving the problems in the background technology and achieving high-efficiency transportation requirements. It can adapt to different displacement and arbitrary high gas-oil ratio conditions, and has a strong adaptability to changes in gas-liquid volume of oil products in different blocks and different development stages.

[0018] 2. The purpose of setting up two buffer tanks is that when one buffer tank is collecting crude oil, the other buffer tank can be pressurized and transported by a compressor when it is full. The two buffer tanks can be used alternately, which further improves the transportation efficiency.

[0019] 3. This utility model uses a slug catcher to capture liquid plugs flowing out of a multiphase flow pipeline, separates oil and water from gas, provides a buffer volume for fluctuations in the incoming liquid volume, and improves the adaptability of the device.

[0020] 4. The slug flow trap is also equipped with a sand removal function, eliminating the risk of pipeline erosion and leakage. The device uses electric valves for process switching, achieving a high degree of automation. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the overall structure of the oil and gas mixed transportation device provided in the embodiment of this utility model.

[0023] In the diagram: 1. First valve; 2. Slug catcher; 3. Second valve; 4. Compressor; 5. Regulating valve; 6. First electric valve; 7. Second electric valve; 8. First buffer tank; 9. Third electric valve; 10. Fourth electric valve; 11. Fifth electric valve; 12. Second buffer tank; 13. Sixth electric valve; 14. Skid. Detailed Implementation

[0024] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0025] Example 1: This embodiment provides an oil-gas mixed transportation device suitable for high gas-oil ratio conditions, including a slug trap 2, two buffer tanks (8, 12), and a compressor 4. The inlet of the slug trap 2 is connected to the transportation pipeline through a first valve 1. The outlet of the slug trap 2 is divided into two branches. The first branch is connected to the inlet of the buffer tank 8 through a first electric valve 6, and the second branch is connected to the inlet of the buffer tank 12 through a fourth electric valve 10. The outlet of the slug trap 2 is connected to the inlet of the compressor 4 through a second valve 3. The outlet of the compressor 4 is also divided into two branches and connected to the inlets of the two buffer tanks. Specifically, the first branch is connected to the inlet of the buffer tank 8 through a second electric valve 7, and the second branch is connected to the inlet of the buffer tank 12 through a fifth electric valve. The outlet of the compressor is connected to the external transportation pipeline through a regulating valve. The outlets of the two buffer tanks are connected to the external transportation pipeline through a third electric valve 9 and a sixth electric valve 13, respectively.

[0026] In this embodiment, a skid mount 14 is also included, on which the slug catcher 2, the two buffer tanks (8, 12) and the compressor 4 are all mounted.

[0027] In this embodiment, the compressor 4 includes a frequency converter, a compressor main unit, an explosion-proof motor, a buffer tank, a cooler, and a lubrication system. The slug trap 2 has pressure transmitters at both its exhaust port and drain port, and the compressor has pressure transmitters at both its inlet and exhaust ports. The buffer tank has both a pressure transmitter and a level transmitter. Support frames are fixedly connected to the bottom of the slug trap, buffer tank, and compressor, and the bottom of the support frames is fixedly connected to the skid 14. Furthermore, a control cabinet is fixed to the edge of the skid 14.

[0028] This invention is applicable to oil and gas mixed transportation conditions, especially for conditions with a high gas-oil ratio. The aforementioned device mainly involves a two-stage process: a crude oil liquid phase storage process and a crude oil liquid phase pressurization and mixed transportation process.

[0029] The crude oil liquid phase storage process is as follows: After confirming that the slug trap 2 and the buffer tank 8 are in pressure balance, the first electric valve 6 is opened (the third electric valve 9 is closed). The produced fluid from the wellhead enters the slug trap 2 through the first valve 1 for gas-liquid separation. The separated gas enters the compressor 4 through the second valve 3 for pressurization, and then is output after being throttled by the regulating valve 5. The separated liquid enters the first buffer tank 8 for storage through the first electric valve 6.

[0030] Crude oil liquid phase pressurization process: When the liquid level in the first buffer tank 8 reaches a high value, after confirming that the pressure of the slug trap 2 and the second buffer tank 12 is balanced, the fourth electric valve 10 is opened (the sixth electric valve 13 is closed), the first electric valve 6 for liquid inlet of the first buffer tank 8 is closed, and the third electric valve 9 for liquid outlet of the first buffer tank 8 and the second electric valve 7 for the compressor exhaust port branch pipeline are opened. After pressurization, natural gas enters the first buffer tank 8, pushing the liquid phase into the external transmission pipeline, where it is combined with the gas after pressurization and throttling by the compressor and then transmitted externally. The purpose of setting up two buffer tanks in this invention is that when one buffer tank is collecting crude oil, the other buffer tank can be pressurized and transported by the compressor when it is full. The two buffer tanks can be used alternately, further improving the transmission efficiency.

[0031] The first and second buffer tanks are used alternately to store and transport crude oil.

[0032] This invention provides an oil-gas mixed transport device suitable for high oil-gas ratios. After gas-liquid separation, a compressor pressurizes the gas phase in the produced fluid, and the gas phase drives the liquid phase for transport. This avoids the problem of traditional oil-gas mixed transport devices failing to pressurize produced fluids with high gas content, and achieves closed-loop oil-gas transport, thus solving the problems in the background technology. It can adapt to different displacements and arbitrary high gas-oil ratios, and has strong adaptability to changes in the gas-liquid volume of oil products in different blocks and at different development stages.

[0033] This embodiment also provides an oil and gas transportation system, including the oil and gas mixed transportation device as described above, which is suitable for high gas-oil ratio conditions.

[0034] Example 2: This embodiment is basically the same as the structure of embodiment 1, except that: the bottom of the slug flow trap is provided with a sand removal port, and the slug flow trap is also equipped with a sand removal function, which eliminates the hidden dangers of pipeline erosion and leakage.

[0035] The embodiments described above are some, but not all, of the embodiments of this application. The detailed description of the embodiments of this application is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

Claims

1. An oil-gas mixing and transportation device suitable for high gas-oil ratio conditions, characterized in that: The device includes a slug trap, at least one buffer tank, and a compressor. The drain port of the slug trap is connected to the inlet of the buffer tank via a valve. The exhaust port of the slug trap is connected to the inlet of the compressor via a valve. The exhaust port of the compressor is connected to the inlet of the buffer tank via a valve. Both the exhaust port of the compressor and the drain port of the buffer tank are connected to an external delivery pipeline via valves.

2. The oil-gas mixed transportation device suitable for high gas-oil ratio conditions according to claim 1, characterized in that: At least two buffer tanks are provided, arranged side by side. The liquid inlet of each buffer tank is connected to the liquid outlet of the slug trap, the air inlet of each buffer tank is connected to the exhaust port of the compressor, and the liquid outlet of each buffer tank is connected to an external delivery pipeline.

3. The oil-gas mixing and transportation device suitable for high gas-oil ratio conditions according to claim 1 or 2, characterized in that: It also includes a skid mount, on which the slug catcher, buffer tank and compressor are all mounted.

4. The oil-gas mixed transportation device suitable for high gas-oil ratio conditions according to claim 1 or 2, characterized in that: The compressor includes a frequency converter, a compressor main unit, an explosion-proof motor, a buffer tank, a cooler, and a lubrication system.

5. The oil-gas mixed transportation device suitable for high gas-oil ratio conditions according to claim 1 or 2, characterized in that: A throttling valve is installed on the external discharge pipeline of the compressor.

6. The oil-gas mixed transportation device suitable for high gas-oil ratio conditions according to claim 1 or 2, characterized in that: The slug trap is equipped with pressure transmitters at both its exhaust port and drain port, the compressor is equipped with pressure transmitters at both its inlet and exhaust port, and the buffer tank is equipped with both a pressure transmitter and a level transmitter.

7. The oil-gas mixed transportation device suitable for high gas-oil ratio conditions according to claim 1 or 2, characterized in that: The slug catcher is equipped with a sand removal port at the bottom, the buffer tank is equipped with a drain port at the bottom, and the compressor is equipped with a drain pipeline at the bottom.

8. The oil-gas mixed transportation device suitable for high gas-oil ratio conditions according to claim 2, characterized in that: The bottom of the slug trap, buffer tank, and compressor are all fixedly connected to a support frame, and the bottom of the support frame is fixedly connected to the skid.

9. The oil-gas mixing and transportation device suitable for high gas-oil ratio conditions according to claim 8, characterized in that: The control cabinet is fixed at the edge of the skid.

10. An oil and gas transportation system, characterized in that: Includes the oil-gas mixed transportation device suitable for high gas-oil ratio conditions as described in any one of claims 1-9.

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