Testing device for competitive adsorption of supercritical CO2 and CH4 in shale and testing method of device

Abstract

The invention provides a testing device for competitive adsorption of supercritical CO2 and CH4 in shale and a testing method of the device. The device comprises an injection pump system, a long core holder, a back-pressure valve, a differential pressure gauge, a temperature control system, a liquid fraction collector, a gas meter and a gas chromatograph instrument. The testing method comprises an evaluation method of CH4 single component gas in a shale core and an evaluation method of CH4 gas, converted by the supercritical CO2, in the shale core. According to the device and method, the detection conditions of a laboratory test that the supercritical CO2 displaces CH4 adsorbed in the shale under the high temperature and high pressure conditions of a stratum are met through a multifunctional long core displacement method, and then the purpose of evaluating the efficiency that the supercritical CO2 displaces the adsorbed CH4 is achieved; by using the combined long core, the gas injection volume is large, the errors are decreased, and the formation condition is truly restored; the cracked long core can simulate the competitive adsorption process of the fractured supercritical CO2 and the CH4 under the true shale reservoir condition; the injected CO2 is in the supercritical state, and an experiment is performed in a step-by-step depressurizing mode, and the depletion exploitation process of a stratum can be truly simulated.

Description

technical field [0001] The invention belongs to the technical field of simulation detection experiments, and in particular relates to the simulation and detection technology of the desorption and replacement effect of supercritical carbon dioxide on adsorbed methane gas in shale under high temperature and high pressure, which is used to guide the improvement of reasonable and efficient mining technology of shale gas. Background technique [0002] The world's shale gas resources are huge. With breakthroughs in North American shale gas exploration and development technology and rapid growth in production, shale gas has been considered as an unconventional natural gas with great mining value. It is very important to understand the development characteristics and development methods of shale gas reservoirs, and to consider how to achieve enhanced shale gas recovery. In shale gas reservoirs, it is generally believed that natural gas occurs in three forms: adsorbed gas, free gas, ...

AI Technical Summary

Problems solved by technology

But at present domestic and foreign to CO 2 Adsorption of CH in displacement shale 4 There are still very few laboratory test evaluations, and most of the tests that have been carried out cannot meet the conditions of high temperature and high pressure in the formation, especially the actual state of shale can not be simulated more completely and comprehensively, so that the actual production situation cannot be restored, so as to better guide the shale gas production process. Reasonable and efficient mining, improve efficiency

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