Propagation of hydraulic fracture under different in-situ stress and its application
In cross-seam hydraulic fracturing, coal seam permeability can be increased by the extension of the original cracks or secondary cracks formed due to the tensile stress concentration at the crack tip.To better understand the propagation of cracks in hydraulic fracturing and guide the research of increasing gas drainage in low permeability coal seams, a theoretical model of crack initiation pressure and propagation direction under different in-situ stress was established by employing the theory of elasticity and the fracture criterion of maximum tensile strength and the rock damage and failure process seepage-stress coupling analysis system RFPA2D-FLOW; This paper simulates cracks formation and expansion in hydraulic fracturing process; compares and analyzes the progressive expansion and rupture process under different in-situ stress in coal seam; obtains the regression curves of horizontal pressure coefficient and initiation pressure; obtains the development trends of crack initiation pressure, extension pressure, and horizontal pressure coefficient.The results are applied to analyze an underground hydraulic fracturing test that shows the permeability coefficient in coal seam was improved by 82~ 180 times of the original, and net gas drainage quantity was 6.4~22.8 times of the original at a gas roadway in Chongqing coal mine of China.
hydraulic fracturing crack prolongation numerical analysis RFPA2D-FLOW
Li Dong Lu Yiyu Huang Changwen Guo Chenye Wang Shuqi He Xingling
State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing, China;Science and Techno State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing, China Chongqing Energy Investment Group, Chongqing, China Science and Technology Co., Ltd., Chongqing Energy Investment Group, Chongqing, China
国际会议
The 34th International Conference on Ground Control in Mining (ICGCM) 2015(34届国际采矿岩层控制会议)
焦作
英文
169-173
2015-10-17（万方平台首次上网日期，不代表论文的发表时间）