Seepage simulation method for constructing coal body based on finite element-discrete element CT (Computer Tomography)

Abstract

The invention discloses a seepage simulation method for constructing a coal body based on finite element-discrete element CT (Computer Tomography). The method comprises the following steps: performing industrial CT scanning to obtain a three-dimensional data body of the coal body, performing three-dimensional reconstruction, and removing an ''island block'' to obtain a general three-dimensional geometric model which can be called by simulation software; writing a coal body fracture discrimination algorithm by a discrete element simulation method, and determining whether the coal body is deformed, even fractured under the action of hydraulic pressure stress; meanwhile, realizing migration of coal body fragments formed after fracture in the coal body along with moisture flow based on an finite element simulation method by a mobile grid method; and performing numerical simulation of a moisture seepage pressure field, a seepage speed field and a coal body moisture increment at the same time in order to reveal deformation and fracture phenomena of the coal body and a migration rule of moisture in a water injection process of a porous medium coal bed to the maximum extent.

Description

technical field [0001] The invention relates to the field of mine rock mechanics, in particular to a seepage simulation method based on finite element-discrete element CT reconstruction of coal body. Background technique [0002] Coal seam water injection can effectively wet the coal body, release the elastic energy of the coal body, increase its plasticity, change the adsorption-desorption gas properties of the coal body, and have the effect of displacing gas. One of the common methods of highlighting with gas. In particular, high-pressure water injection in coal seams increases the effect of hydraulic fracturing on the basis of ordinary seepage, and increases the wetting effect of coal by creating new cracks. The whole process involves multiple disciplines such as computational fluid dynamics, fracture rock mechanics and fluid-solid coupling, and the process of numerical simulation is relatively complicated. [0003] At present, most of the numerical simulation studies o...

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Problems solved by technology

However, as a typical porous media material, the essence of coal wetting is that water enters the many fine pores in the coal body, and the simulation from a macro perspective cannot reproduce this process for in-depth research

Moreover, most of the current research on water seepage is based on finite element or discrete element analysis alone, and finite element is difficult to realize coal fracture, and discrete element cannot accurately describe the seepage process and water increment data

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