Numerical simulation research on failure law of surrounding rock in coalbed methane well

2018 1st International Conference on Environment Prevention and Pollution Control Technology

生态环境科学

Liu, Chao^1,2 ; Yang, Mingyang^2 ; Yu, Guofeng^1 ; Duan, Changrui^1

Coal Mining National Engineering Technology Research Institute, Huainan, Anhui

232001, China^1

School of Safety Science and Engineering, Xi'An University of Science and Technology, Xi'an

710054, China^2

关键词: Coal bed methane wells;    Confining pressures;    Damage initiation;    Failure mechanics;    Failure process;    Inhomogeneous materials;    Numerical simulation research;    Surrounding rock;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/199/2/022038/pdf
DOI  :  10.1088/1755-1315/199/2/022038

学科分类：环境科学（综合）

来源: IOP

【 摘 要 】

The entire process of fracturing at different sections, were namely 1-1(wellhead), 2-2(well middle), 3-3(well bottom), was simulated to study the failure law of surrounding rock at different depths. The failure mechanics of borehole rock mass was analysed using Realistic Failure Process Analysis (RFPA) software. The results showed that as the depth of wells continues to deepen, the crack propagation was restrained relatively by inhomogeneous materials in rock mass. In addition, with the increase of inhomogeneous materials in the surrounding rock, the brittle of rock and peak strength of the fracture gradually increase. The entire process of rock failure was corresponded to three stages, namely damage initiation, restriction propagation and rock failure. As the depth of wells deepens, the steps in damage initiation gradually decreased compared with the steps in restriction propagation stage. As the confining pressure continues to increase, the accumulated energies in the rock mass reached the peak strength of the crack, it would immediately violently crack.