Shale oil associated gas decarburization and liquefaction treatment device

Abstract

The utility model relates to the field of oilfield development and production, in particular to a shale oil associated gas decarburization and liquefaction treatment device which comprises a membrane separation device, a Freon refrigeration skid and a low-temperature separator, a gas inlet of the membrane separation device is connected with a pipeline I, the pipeline I is connected with an associated gas inlet pipeline II, a gas outlet of the membrane separation device is connected with the Freon refrigeration skid through a pipeline II, and the Freon refrigeration skid is connected with the low-temperature separator through a pipeline III; the low-temperature separator is connected with the pipeline I through a return pipeline; the first pipeline is connected with the Freon refrigeration skid through a fourth pipeline. According to the utility model, membrane separation and low-temperature separation are coupled and modular design is adopted, so that not only is decarburization and liquefaction treatment of shale oil associated gas effectively realized, but also installation and maintenance are more convenient.

Description

Technical Field

[0001] The utility model relates to the field of oil field development and production, and in particular to a shale oil associated gas decarbonization and liquefaction processing device. Background Art

[0002] As an efficient and clean energy, natural gas is an important part of the energy structure. With the continuous development of various oil and gas fields, the collection and transportation technology of carbon dioxide driven produced fluids has been gradually improved. However, due to the high CO2 content in associated gas, the use of conventional associated gas processing equipment will cause a large amount of CO2 waste and is not conducive to emission reduction. Considering the scattered test blocks and the difficulty of building a centralized processing station, it is advisable to choose to use skid-mounted processing equipment to recycle and re-inject CO2. The recycling and re-injection process of CO2 is actually the process of purifying and liquefying carbon dioxide gas.

[0003] As a produced gas purification process, membrane separation has the advantages of easy skid installation, low energy consumption, large operational flexibility, strong processing capacity, and high removal rate. However, the CO2 content of produced gas varies widely, and the removal of gaseous CO2 requires liquefaction, so a single membrane separation technology cannot meet the needs. Utility Model Content

[0004] The purpose of the utility model is to overcome the shortcomings of the prior art and propose a shale oil associated gas decarbonization and liquefaction processing device to achieve the decarbonization and liquefaction processing of shale oil associated gas. The membrane separation and low-temperature separation are coupled and modularized to make installation and maintenance more convenient and reliable.

[0005] The technical solution adopted by the utility model to solve its technical problems is:

[0006] A shale oil associated gas decarbonization and liquefaction processing device comprises a membrane separation device, a Freon refrigeration skid and a low-temperature separator; the air inlet of the membrane separation device is connected to pipeline one, the pipeline one is connected to associated gas inlet pipeline two, the air outlet of the membrane separation device is connected to the Freon refrigeration skid through pipeline two, the Freon refrigeration skid is connected to the low-temperature separator through pipeline three; the low-temperature separator is connected to pipeline one through a reflux pipeline; pipeline one is connected to the Freon refrigeration skid through pipeline four.

[0007] The above technical solution enables the associated gas delivered from the associated gas pipeline 2 to enter the membrane separation device through pipeline 1, and the high-concentration CO2 separated by the membrane separation device enters the low-temperature separator after being refrigerated by the Freon refrigeration skid. The associated gas delivered from the associated gas pipeline 2 can also choose to enter the Freon refrigeration skid directly through pipeline 4, and enter the low-temperature separator for gas-liquid separation after refrigeration, thus realizing the decarbonization and liquefaction treatment of shale oil associated gas. The membrane separation and low-temperature separation are coupled and modularized, which has the advantages of simple structure and strong operability.

[0008] Furthermore, the gas outlet of the membrane separation device is connected to a qualified natural gas export pipeline, so that the separated qualified natural gas is pressurized and exported through the qualified natural gas export pipeline.

[0009] Furthermore, the low-temperature separator is connected to a liquefied CO2 output pipeline, and the separated liquid CO2 enters a rear-end pressurization and reinjection unit through the liquefied CO2 output pipeline.

[0010] Technical effects of the utility model:

[0011] Compared with the prior art, the utility model provides a shale oil associated gas decarbonization and liquefaction processing device, which adopts membrane separation and low-temperature separation coupling and modular design, which not only effectively realizes the decarbonization and liquefaction processing of shale oil associated gas, but also makes installation and maintenance more convenient. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a schematic diagram of the structural principle of the shale oil associated gas decarbonization and liquefaction processing device of the utility model.

[0013] In the figure, 1. membrane separation device; 2. Freon refrigeration skid; 3. low-temperature separator; 4. pipeline one; 5. associated gas pipeline two; 6. pipeline two; 7. pipeline three; 8. reflux pipeline; 9. pipeline four; 10. qualified natural gas export pipeline; 11. liquefied CO2 output pipeline. DETAILED DESCRIPTION

[0014] In order to make the purpose, technical solution and advantages of the embodiments of the utility model clearer, the technical solution in the embodiments of the utility model is clearly and completely described below in conjunction with the accompanying drawings of the specification.

[0015] Embodiment 1:

[0016] like Figure 1 As shown, the present embodiment involves a shale oil associated gas decarbonization and liquefaction processing device, comprising a membrane separation device 1, a Freon refrigeration skid 2 and a low-temperature separator 3; the air inlet of the membrane separation device 1 is connected to a pipeline 1 4, and the air outlet of the membrane separation device 1 is connected to a qualified natural gas export pipeline 10, so that the separated qualified natural gas is pressurized and exported through the qualified natural gas export pipeline 10; the pipeline 1 4 is connected to an associated gas inlet pipeline 2 5, the air outlet of the membrane separation device 1 is connected to the Freon refrigeration skid 2 through a pipeline 2 6, and the Freon refrigeration skid 2 is connected to the low-temperature separator 3 through a pipeline 3 7; the low-temperature separator 3 is connected to the pipeline 1 4 through a reflux pipeline 8; the low-temperature separator 3 is also connected to a liquefied CO2 output pipeline 11, and the separated liquid CO2 enters a rear-end pressurized reinjection unit through the liquefied CO2 output pipeline 11; the pipeline 1 4 is connected to the Freon refrigeration skid 2 through a pipeline 4 9.

[0017] Working principle: The associated gas transported by the associated gas pipeline 2 5 of the present invention can be selected to enter the membrane separation device 1 through the pipeline 1 4, and the high-concentration CO2 separated by the membrane separation device 1 can be passed through the Freon refrigeration skid 2, or can be selected to enter the Freon refrigeration skid 2 directly through the pipeline 4 9. For example: when the CO2 concentration is less than 80%, the associated gas after pressurization and dehydration enters the membrane separation device 1, and the qualified natural gas after separation is pressurized and transported outward. The separated high-concentration CO2 is refrigerated by the Freon refrigeration skid 2 and then enters the low-temperature separator 3 for gas-liquid separation. The separated liquid CO2 enters the rear-end pressurization and reinjection unit, and the unliquefied gas flows back to the air inlet of the membrane separation device 1. When the CO2 concentration is ≥80%, the associated gas after pressurization and dehydration directly enters the Freon refrigeration skid 2 for refrigeration and then enters the low-temperature separator 3 for gas-liquid separation. The separated liquid CO2 enters the rear-end direct pressurization and reinjection, and the unliquefied gas flows back to the air inlet of the membrane separation device 1, and the qualified natural gas is pressurized and transported outward.

[0018] The carbon content of the associated gas after wellhead pressurization and dehydration is less than 80%. If it directly enters the low-temperature separator 3, the liquefaction rate is low and the energy consumption is high. Therefore, the associated gas first enters the membrane separation device 1 for pretreatment and decarbonization. The associated gas is processed into qualified natural gas and sent to the joint station for use or export. The treated high-concentration CO2 gas is sent to the Freon refrigeration skid 2 for shallow cold liquefaction and then enters the low-temperature separator 3. The separated liquefied CO2 is pressurized to the injection pressure and then injected back into the formation through the single well filling pipeline of the injection system through the distribution metering valve group. The associated gas that cannot be liquefied in the low-temperature separator 3 is returned to the membrane separation device 1 to produce qualified commercial gas.

[0019] The above-mentioned specific implementation methods are only specific cases of the present utility model. The patent protection scope of the present utility model includes but is not limited to the above-mentioned specific implementation methods. Any appropriate changes or modifications made to them by ordinary technicians in the relevant technical field in accordance with the claims of the present utility model shall fall within the patent protection scope of the present utility model.

Claims

1. A shale oil associated gas decarbonization and liquefaction processing device, characterized in that: The invention comprises a membrane separation device (1), a Freon refrigeration skid (2) and a low-temperature separator (3); the air inlet of the membrane separation device (1) is connected to a pipeline 1 (4), the pipeline 1 (4) is connected to an associated gas pipeline 2 (5), the air outlet of the membrane separation device (1) is connected to the Freon refrigeration skid (2) through a pipeline 2 (6), the Freon refrigeration skid (2) is connected to the low-temperature separator (3) through a pipeline 3 (7); the low-temperature separator (3) is connected to the pipeline 1 (4) through a reflux pipeline (8); the pipeline 1 (4) is connected to the Freon refrigeration skid (2) through a pipeline 4 (9).

2. The shale oil associated gas decarbonization and liquefaction processing device according to claim 1, characterized in that: The gas outlet of the membrane separation device (1) is connected to a qualified natural gas transmission pipeline (10).

3. The shale oil associated gas decarbonization and liquefaction processing device according to claim 1 or 2, characterized in that: The low-temperature separator (3) is connected to the liquefied CO2 output pipeline (11).

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