Method for testing triple pore deformation coupling rule of coal rock in unbalanced state

Abstract

The invention discloses a method for testing a triple pore deformation coupling rule of coal rock in an unbalanced state, and relates to the technical field of coal rock deformation testing. The method comprises the following steps: firstly, crushing and processing raw coal into a briquette coal sample with a crack in the middle; then, pasting a strain gauge on the surface of the briquette coal sample, covering all the surfaces of the briquette coal sample with a soft silicone rubber adhesive, and reserving gas injection ports at the two ends of the crack; then, putting the briquette coal sample into a pressure container, and integrally putting the pressure container into a constant-temperature chamber; and finally, after the temperature of the constant-temperature chamber is stable, injecting gas, and meanwhile, collecting data of the strain gauge, and measuring strain evolution caused by matrix compression or expansion of the briquette coal sample under the action of gas adsorption. According to the method, the deformation rule of different parts of the matrix of the briquette coal sample under the interaction among the multiple pore systems can be directly observed, and the permeability evolution rule of the multiple pore systems can be inverted by combining numerical simulation.

Description

Technical field [0001] The present invention relates to the field of coal rock deformation testing, and in particular, there is a test method of a triple pore deformation regorination in a non-equilibrium state. Background technique [0002] The experimental study of the interaction of coal matrix - fracture is mainly carried out by measuring the correlation between coal permeability and pore pressure. However, in these penetration experiments, the pressure difference between the matrix system and the crack system is ignored, and it is assumed that the penetration rate obtained in the equilibrium is assumed. Based on this, some scholars have launched the laboratory measurement hole cage deformation experiment, but the experimental study of the coupling phenomenon between the coal reservoir hole cage system is limited to the double pore system, and there is no directly observed between the multi-pore system. Interaction, and does not clearly explain the deformation distribution of...

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Problems solved by technology

However, in these permeability experiments, the pressure difference between the matrix system and the fracture system was ignored, and the obtained permeability was assumed to be the permeability in the equilibrium state

Based on this, some scholars have carried out laboratory experiments to measure the coupling of pore-fracture systems. However, the experimental research on the coupling phenomenon between pore-fracture systems in coal reservoirs is limited to dual pore systems, and no direct observation of the coupling between multiple pore systems has been performed. interaction, and does not clearly account for the deformation distribution of different parts of the sample matrix under the interaction of multiple pore systems

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