Simulating test method of CH4 layered displacement by CO2 in multi-layer superposed gas-containing system

Abstract

The invention discloses a simulating test method of CH4 layered displacement by CO2 in a multi-layer superposed gas-containing system. The simulating test method comprises the following steps of preparing tests, loading stress, adsorbing gas, displacing methane, and completing the primary test and the other tests in the same group. Permeable plates of the inner bottom of a test-piece box adopted by the tests are arranged in a sectionalized mode, and an airflow passageway is formed below each permeable plate. When moulded coal is formed, coal layers in the test-piece box corresponds to the permeable plates one to one, and similar materials are arranged between the coal layers in a spaced mode so as to simulate a rock layer. An extracting branch pipe with the direction contrary to the Y-direction pressure is buried in each coal layer. Therefore, the simulating test method of CH4 layered displacement by the CO2 in a horizontal well of the multi-layer superposed gas-containing system lays the foundation for follow-up study of CH4 displacement by the CO2 in the horizontal well of the multi-layer superposed gas-containing system.

Description

technical field [0001] The invention belongs to the technical field of coalbed methane exploitation simulation test, and in particular relates to a multi-layer stacked gas-containing system CO 2 Stratified displacement of CH 4 Simulation test method. Background technique [0002] At present, coalbed methane is a kind of unconventional natural gas generated from coal seams and mainly stored in coal seams in the state of adsorption, and its main component is methane. Coalbed methane is an important new clean energy and strategic resource in the 21st century in my country. my country's coalbed methane resources are huge, among which the resources buried at a depth of 1000-2000m account for more than two-thirds of the total resources at depths below 2000m. The multi-layer stacked gas-bearing system is an academic point of view proposed and proved on the basis of a single coalbed methane-bearing system in recent years. It refers to multiple independent CBM systems vertically ...

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Problems solved by technology

[0005] Currently about CO 2 Displace CH 4 The simulated experiments are mainly carried out under small-scale and pseudo-triaxial conditions, which cannot effectively eliminate the boundary effect and cannot truly restore the complex geological conditions on site. Most importantly, it is difficult to conduct CO 2 Stratified displacement of CH 4 Therefore, it is necessary to propose a multi-layer stacked gas-containing system CO 2 Stratified displacement of CH 4 Simulation test method to make up for this deficiency

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