Visualized test device and method for simulating underground coalbed methane occurrence and desorption process

Abstract

The invention relates to a visualized test device for simulating the underground coalbed methane occurrence and desorption process. The device includes: a visualized simulation subsystem, a gas injection control subsystem, a constant pressure and constant speed pump, and a gas-water separation metering subsystem. The visualized simulation subsystem is used for visualized simulation of the gas-water dynamic change situation of the underground coalbed methane occurrence and desorption process, the gas injection control subsystem is used for supercharging or vacuum pumping of the injected gas ofthe visualized simulation subsystem, the constant pressure and constant speed pump is used for injecting water or extraneous liquid to the visualized simulation subsystem to construct an underground hydrodynamic field or extraneous engineering fluid affected environment, and a gas-water separation metering apparatus of the gas-water separation metering subsystem is used for separation metering ofgas-water mixed fluid discharged by the visualized simulation subsystem. The design environment provided by the invention comprehensively reflects the influence of the underground initial temperaturefield, hydrodynamic field, extraneous engineering fluid and the like on the underground coalbed methane occurrence and desorption law, and more truly reproduces the output change process of gas and water phases in the drainage and pressure reduction exploitation process of underground coal seams.

Description

technical field [0001] The invention belongs to the field of petroleum engineering, and in particular relates to a visualization test device and method for simulating the storage and desorption process of underground coalbed methane. Background technique [0002] Under formation conditions, the CBM reservoir is a solid-liquid-gas three-phase coupling system, in which the coalbed water fills the coalbed cleats and matrix pores to form a closed pressure system, and the CBM is mainly adsorbed under the action of confined water. The state exists in the matrix pores. In addition, the initial water saturation of coal seams is generally high. CBM development mainly adopts drainage and depressurization technology to promote the desorption, migration and output of adsorbed gas in coal seams by draining formation water. Injection is essential, and the injection of liquid will also change the original environmental conditions of coal reservoirs, which will affect the ability of coal t...

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Problems solved by technology

[0004] Through the comparison of technical features, this patent application is quite different from the above-mentioned published patent documents. The devices and methods disclosed in the above-mentioned published patent documents cannot truly restore the confined water geological conditions of the initial coal seam solid-liquid-gas three-phase coupling system. Intuitive and quantitative analysis of water production and gas production characteristics in the process of coal seam drainage and pressure reduction

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