CN-224215133-U - CO (carbon monoxide) treatment method2Pressurized reinjection underground device

Abstract

The utility model discloses a device for pressurizing and reinjecting CO 2 into the ground, which comprises a first heat exchanger, a second heat exchanger, a refrigerating unit, a buffer tank, a booster pump and a third heat exchanger, wherein the input end of the first heat exchanger is connected with a CO 2 storage tank through a pressure regulating valve, the output end of the first heat exchanger is connected with the input end of the buffer tank through the second heat exchanger, a cold source of the second heat exchanger is provided by the refrigerating unit, and the output end of the buffer tank is connected with a stratum through the booster pump, the first heat exchanger and the third heat exchanger in sequence.

Inventors

• MAO HAIDONG
• DONG XIANYING
• LU ZIXU

Assignees

• 天津斯必德工程科技有限公司

Dates

Publication Date

20260508

Application Date

20250520

Claims (7)

1. 1. The device for pressurizing and reinjecting CO 2 into the ground is characterized by comprising a first heat exchanger, a second heat exchanger, a refrigerating unit, a buffer tank, a booster pump and a third heat exchanger, wherein the input end of the first heat exchanger is connected with a CO 2 storage tank through a pressure regulating valve, the output end of the first heat exchanger is connected with the input end of the buffer tank through the second heat exchanger, a cold source of the second heat exchanger is provided by the refrigerating unit, and the output end of the buffer tank is connected with a stratum through the booster pump, the first heat exchanger and the third heat exchanger in sequence.
2. 2. The apparatus for pressurizing and reinjecting CO 2 into the ground as defined in claim 1, wherein a compressor is further connected between said CO 2 storage tank and said first heat exchanger.
3. 3. The apparatus for pressurizing and reinjecting CO 2 into the ground as defined in claim 1, wherein said first heat exchanger and said second heat exchanger are each of a plate or shell and tube configuration.
4. 4. The apparatus for pressurizing and reinjecting CO 2 into the ground according to claim 1, wherein the refrigeration unit comprises a refrigerant, a refrigerant compressor, a condenser, an evaporator and an on-line control module, wherein the refrigerant is recycled by using R22, R23, R404A, R, ethanol, propane, ethylene, ethane.
5. 5. The apparatus for pressurizing and reinjecting CO2 into the ground according to claim 1, wherein the third heat exchanger is an air-temperature type reheater or a water bath type reheater.
6. 6. The apparatus for pressurizing and reinjecting CO 2 into the ground as defined in claim 1, wherein said booster pump employs a reciprocating pump or a multistage centrifugal pump.
7. 7. A device for pressurizing and reinjecting CO 2 back into the ground as defined in any one of claims 1-6, wherein said device is of a fully skid-mounted construction.

Description

Device for pressurizing and reinjecting CO 2 into underground Technical Field The utility model belongs to the technical field of CO 2 liquid or supercritical reinjection utilization, and particularly relates to a device for pressurizing and reinjecting CO 2 into the ground. Background Supercritical CO 2 has high diffusivity and fluidity, facilitating its transport in the wellbore. 1. Supercritical state-at the beginning of injection, CO 2 remains supercritical due to the pressure in the wellbore being much greater than the critical pressure of CO 2. 2. Liquid state as the injection proceeds, the temperature of the CO 2 gradually decreases, possibly transitioning from a supercritical state to a liquid state. This transition occurs in cooler regions of the wellbore, particularly near the reservoir. 3. Returning again to the supercritical state, when the liquid CO 2 is further injected and contacts the higher temperature region, it will return again to the supercritical state. This phase transition process will fill the wellbore with supercritical CO 2 at the end of injection. CO 2 reinjection (CO 2 Injection) is a technology for capturing and injecting carbon dioxide (CO 2) into the ground, mainly for reducing greenhouse gas emissions, improving oil and gas recovery (EOR), and geological sequestration. Wherein, the emission reduction of greenhouse gases, CO 2 is one of main greenhouse gases, and the global warming is caused by the large-scale emission. By capturing and injecting CO 2 from industrial emissions into the ground, it is possible to reduce its entry into the atmosphere. And in the oil gas exploitation, CO 2 reinjection can improve the oil gas exploitation, and especially in the later development stage of an oil field, CO 2 can be mixed with crude oil, so that the viscosity is reduced, and the exploitation is convenient. Geological sequestration, namely injecting CO 2 into deep geological structures (such as depleted oil-gas fields, salty water layers and the like), realizing long-term sequestration and reducing the concentration of CO 2 in the atmosphere. How to effectively reinject CO 2 into the stratum is a technical problem that needs to be solved by those skilled in the art. Disclosure of utility model Aiming at the technical problems in the prior art, the utility model provides a device for pressurizing and reinjecting CO 2 into the ground, which can effectively discharge CO 2 into a stratum, prevent CO 2 from being discharged in the atmosphere and protect the ecological environment. Meanwhile, the utility model adopts a cooling source provided by a circulating refrigeration system in the liquefaction process through the precooling, liquefying, pressurizing and reheating unit processes of the gaseous CO 2, and the pressurizing process is realized by a low-temperature booster pump, and the reheating can be an air-temperature type reheater or a water-bath type reheater. The utility model can realize high-pressure reinjection of CO 2, reduce the emission of CO 2 gas, improve the oil and gas recovery ratio and realize geological sequestration of CO 2. In order to solve the problems in the prior art, the utility model adopts the following technical scheme: The device for pressurizing and reinjecting CO 2 into the ground comprises a first heat exchanger, a second heat exchanger, a refrigerating unit, a buffer tank, a booster pump and a third heat exchanger, wherein the input end of the first heat exchanger is connected with a CO 2 storage tank through a pressure regulating valve, the output end of the first heat exchanger is connected with the input end of the buffer tank through the second heat exchanger, a cold source of the second heat exchanger is provided by the refrigerating unit, and the output end of the buffer tank is connected with a stratum through the booster pump, the first heat exchanger and the third heat exchanger in sequence, wherein: And (3) reducing the pressure of the gaseous CO 2 or the supercritical CO 2 stored in the storage tank to 0.5-3 MPaG through a pressure regulating valve, inputting the gaseous CO 2 or the supercritical CO 2 into a first heat exchanger, a second heat exchanger and a refrigerating unit, exchanging heat and cooling the gaseous CO 38324 to-5 ℃ to-60 ℃ and then delivering the liquid CO 2 into a buffer tank for buffering, at the moment, pressurizing the low-temperature liquid CO 2 to the high-pressure liquid CO 2 of 10-40 MPa through the pressure regulating valve, and then heating the high-pressure liquid CO 2 to the liquid CO 2 or the supercritical CO 2 of 0-50 ℃ through a third heat exchanger and injecting the liquid CO into a stratum. Further, a compressor is further connected between the CO 2 storage tank and the first heat exchanger. Further, the first heat exchanger and the second heat exchanger are both in plate-type or shell-and-tube structures. Further, the refrigeration unit comprises a refrigerant, a refrigerant compressor, a condenser, an evapor