Device and method for testing porosity and adsorption parameters of gas-bearing shale

Abstract

The invention discloses a device and a method for testing porosity and adsorption parameters of gas-bearing shale, belonging to the fields of shale engineering and unconventional gas engineering. The device for testing the porosity and adsorption parameters of the gas-bearing shale comprises a constant-temperature triaxial cell, an axial pressure loading system, a confining pressure loading system, an upper end adsorbing system, a lower end adsorbing system, a vacuuming system, a constant temperature system and a data acquisition control system. The method for testing the porosity and adsorption parameters of the gas-bearing shale is used for simultaneously testing the porosity and adsorption parameters of the shale at different temperatures and under different bias environments and calculating the real adsorption quantity and is applicable to the environment with deep high ground stress and high temperature, the axial pressure is as high as 300MPa, the confining pressure is as high as 100MPa, the pressure of filled gas is as high as 70MPa, the highest temperature is up to 100 DEG C, a sample is a virgin rock core of which the size is as large as Phi 50mm*100mm, the test time is saved by nearly 75%, and the test efficiency is improved greatly.

Description

technical field [0001] The invention belongs to the field of rock engineering and unconventional natural gas engineering, and particularly relates to a testing device and method for porosity and adsorption parameters of gas-bearing shale. Background technique [0002] Micro-cracks and pores in gas-bearing shale are the storage space for methane molecules. According to the geological parameters of gas-bearing shale in the United States, 25%-60% of methane molecules exist in the intergranular pores of the inorganic matrix of gas-bearing shale in a free state. And in natural fissures, 40%-75% of methane molecules exist in the adsorbed state on the surface of organic matter pores such as kerogen and clay particles. The initial high production of gas-bearing shale mainly depends on the free gas in pores and fractures, while the long-term stable production depends on the adsorbed gas in organic matter and clay particles. At present, the exploration and development of shale gas in...

AI Technical Summary

Problems solved by technology

During the test, temperature fluctuations will lead to unstable gas injection pressure, which will cause errors in the test of the amount of adsorbed gas. In previous tests, only the sample was heated, and the heating and constant temperature of the injected gas were not considered.

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