Carbon dioxide flooding process

Abstract

The carbon dioxide flooding process belongs to the technical field of carbon dioxide flooding. Close the liquid inlet pipeline (4) and the carbon dioxide injection pipeline (9), open the gas return pipeline (5), the pressure of the pump chamber of the carbon dioxide injection pump (14) and the upper part of the carbon dioxide storage tank (1) reach equilibrium; start the carbon dioxide injection pump (14), to pre-cool the carbon dioxide injection pump (14) and pipeline; when the temperature of the carbon dioxide injection pump (14) is lower than -8°C, open the injection valve (11) on the carbon dioxide injection pipeline (9), Stop precooling and inject carbon dioxide downhole. After the carbon dioxide is injected into the pump cavity of the pump (14) and the pressure is formed in the pipeline, it can prevent the liquid carbon dioxide from forming dry ice in the pipeline due to the pressure difference, so as to ensure stable work and avoid dry ice from damaging the pipeline, pump and valve. It has been verified by experiments , the process can effectively improve the service life of valves and pumps.

Description

technical field [0001] The carbon dioxide flooding process belongs to the technical field of carbon dioxide flooding. Background technique [0002] The applicant applied for a carbon dioxide injection pump for gas-liquid separation before, and returned the gaseous carbon dioxide to the carbon dioxide storage tank, thereby effectively overcoming the carbon dioxide waste and environmental pollution caused by the forced exhaust of the previous carbon dioxide injection pump. At the same time, the work is safer. The applicant found in the actual operation process that when the carbon dioxide injection pump starts to work, the pressure in the pump chamber and the pressure in the pipeline are the same as the external atmospheric pressure. If the carbon dioxide injection pump is started directly at this time, the liquid will The carbon dioxide in the liquid is easy to form dry ice in the liquid inlet pipe, and the dry ice will cause damage to the valve on the pipe, and the dry ice w...

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Problems solved by technology

[0002] The applicant applied for a carbon dioxide injection pump for gas-liquid separation before, and returned the gaseous carbon dioxide to the carbon dioxide storage tank, thereby effectively overcoming the carbon dioxide waste and environmental pollution caused by the forced exhaust of the previous carbon dioxide injection pump. At the same time, the work is safer. The applicant found in the actual operation process that when the carbon dioxide injection pump starts to work, the pressure in the pump chamber and the pressure in the pipeline are the same as the external atmospheric pressure. If the carbon dioxide injection pump is started directly at this time, the liquid will The carbon dioxide is easy to form dry ice in the liquid inlet pipe, and the dry ice will cause damage to the valve on the pipe, and the dry ice will even enter the pump chamber, causing the entire carbon dioxide injection pump to fail to work normally.

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