Three-axis permeability testing method

Abstract

The invention discloses a three-axis permeability testing method, and belongs to the field of coal bed gas exploitation. A rock sample is placed in a model system (1), then pressure pulse is applied on the rock sample; a gas control system (2) supplies test gas to the model system (1); a temperature control system (3) controls the temperature of the model system (1); a three-axis loading system (4) applies confining pressure and axial pressure on the rock core clamper of the model system (1); a vacuumizing system (5) vacuumizes the test device; a gas sample collecting system (6) detects the gas components after the test; and an electrical controlling and monitoring system monitors the test process. The method comprises following steps: filling a sample into a tank, checking the airtightness, carrying out a permeability test, and cleaning the test system. The provided method can simulate a high temperature and high pressure environment of a deep stratum in a lab; pressure pulse is applied on the inlet end of a rock sample, the attenuation data of pressure pulse can be obtained, and then the rock sample permeability is calculated based on the attenuation data. The test efficiency ishigh, the external interference is little, and the test result is more accurate.

Description

technical field

[0001] The invention relates to a test method, in particular to a triaxial permeability test method, which belongs to the field of coal bed gas exploitation. Background technique

[0002] Coal bed methane (coal mine gas) and shale gas are new types of efficient and clean energy. The development of coalbed methane and shale gas is of great significance to alleviating the shortage of oil and gas resources in my country, reducing the degree of mine disasters, and reducing greenhouse gas emissions. my country is rich in coalbed methane and shale gas resources, and the reserves of coalbed methane shallower than 2000m reach 36.81×10 12 m 3 , shale gas reserves up to 30×10 12 m 3 Above, the development potential is huge. However, the development and utilization rate of coalbed methane and shale gas in my country is relatively low. An important factor restricting their development is that coal seams and shale are tight rock formations with low permeability in ge...

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