System and method for displacing shale gas with CO2 and simulating and testing adsorption and desorption of shale to shale gas or CO2

Abstract

A system for displacing shale gas with CO2 and simulating and testing adsorption and desorption of shale to the shale gas or CO2 comprises a CO2 bottle and a CH4 bottle, the CO2 bottle is connected to the input end of a first piston container, the CH4 bottle is connected to the input end of a second piston container, the power driving ends of the first piston container and the second piston container are connected with a power driving system, the output ends of the first piston container and the second piston container are connected to the input end of a sand-filled tube, a connecting pipeline for connecting the output ends with the input end is provided with a vacuum pump and a calibration system, the sand-filled tube is arranged in a thermotank and is connected with an axial pressure pump, the output end is connected to a tail gas recovering bottle, and a pipeline for connecting the output end with the tail gas recovering bottle is provided with a back pressure control system and an infrared gas analyzer. The invention also provides a method based on the system. The system and the method can simulate and test the effect of displacement of the shale gas with CO2 in different states at different temperatures under different pressures; and an experiment device is used to carry out experiments of adsorption and desorption of the shale to CH4 or CO2 and research the gas adsorption and desorption rule of the shale at different temperatures under different pressures.

Description

Technical field [0001] The invention belongs to the technical field of oil and gas field development engineering, and particularly relates to a CO 2 Replacement of shale gas and shale to shale gas (main component CH 4 ) Or CO 2 Adsorption analysis simulation test system and method Background technique [0002] my country's shale gas resources are very rich, and the efficient development of shale gas is of great significance to alleviating the contradiction between my country's energy supply and demand. Because shale gas has the characteristics of low porosity and low permeability, reservoir fracturing must be carried out to develop shale gas. Therefore, the choice of fracturing fluid is very important. According to the experience of the successful exploitation of shale gas in the United States, hydraulic fracturing technology is mainly used, but this technology consumes a lot of water resources and causes serious pollution. [0003] Whether it is CO 2 Fractured shale reservoir, or...

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Problems solved by technology

[0004] However, currently regarding CO 2 The test research on the replacement of methane has the following deficiencies. First, the simulated test of CO 2 Devices that interact with rocks are mostly used to test adsorption isotherms or adsorption isotherms, and to test CO 2 Substitution of CH 4 There are very few devices; secondly, CO 2 Substitution of CH 4 There are many technologies for coal and rock, but very few for shale; finally, the only CO 2 Substitution of CH 4 The gas measuring device used in the device cannot realize real-time monitoring of the replacement effect

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