煤层气井水力压裂同层多裂缝分析

多裂缝理论是水力压裂理论的前沿理论,特别是对裂隙发育、物理力学性质有别于均质砂岩的煤岩,其研究难度较大,面临问题很多。根据弹性力学、岩石力学、断裂力学和流体力学等学科基本理论,结合多裂缝理论与井底压力协同理论,对在天然裂隙发育的煤层同时开启的多裂缝模型进行了分析与计算。结果显示,综合滤失系数、流量、主应力差等均不同程度影响了多裂缝在近井筒区域的汇合相连概率与延伸方向。

Multiple fractures in the same seam in hydraulic fracturing of CBM well

The multiple fracture theory is the hydraulic fracturing frontier theory, especially for the coal, the fractures, physical and mechanical properties of coal are different from homogeneous sandstone. The study of multiple fracture theory is difficult and faces many problems. Based on the basic theory of elastic mechanics, rock mechanics, fracture mechanics and fluid mechanics, and then combining with the multiple fracture theory and bottom hole pressure synergetic theory, after the analysis and calculation of the multiple fracture mode, we thought that overall fluid loss coefficient, flow and principal stress difference all influence the connection probability and extending direction of the multiple fractures in the near wellbore area.