Coal bed high-pressure water injection fracturing-flow seeping value simulation method

Abstract

The invention discloses a coal bed high-pressure water injection fracturing-flow seeping value simulation method based on a shortest pressure relieving path algorithm. A coal body geometric model is built according to the water injection coal bed height, the strike length and the inclination length; a water injection hole model is added on the basis according to the water injection hole diameter, the length, the inclination angle and the hole sealing length parameter; a fracturing model is added according to the original fracture width, distribution and strike; finally, a combined body is formed through Boolean operation; the tetrahedron mesh generation is performed on the coal body geometric model; the mesh set which is easiest to damage is found, and is regarded as the generated fracture to be marked into the calculation fracture in the original geometric model; the algorithm step of finding the calculation fracture is repeated until all mesh intensity parameters are not lower than the received stress; the path formed by combining the obtained meshes is the shortest pressure relieving path, i.e., the fracture generating and development path is obtained. The water pressure fracturing is accurately simulated, and relevant data of the moving rule of moisture in the coal body is provided for decision makers.

Description

technical field [0001] The invention relates to the field of mine safety, in particular to a coal seam high-pressure water injection fracturing-seepage numerical simulation method based on the least pressure relief path algorithm. 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 characteristics of the coal body, and have the effect of displacing gas. One of the common methods of highlighting with gas. However, due to the complex structure of pores and fissures in the coal body and the inability to effectively monitor the water seepage process, it is difficult to carry out experimental research on the law of water migration in the coal body. At the same time, with the rapid development of modern computing technology and the gradual maturity of rock mechanics and computational fluid dynamics, simulation has become an important me...

AI Technical Summary

Problems solved by technology

[0003] However, in the process of high-pressure water injection in coal seams, the coal body is prone to cracking and cracks under the action of water pressure, and the existing simulation software based on the finite element method is difficult to simulate the coupling flow field while calculating the development of cracks, that is, the model The fissures in must be preset and cannot be changed, which is seriously inconsistent with the actual project

Images