煤层水力压裂过程“三场”演化规律特征  

Regularity of three fields evolution of hydraulic fracturing process in coal seam

作　　者：许昭勇 宋大钊[2,3] 邱黎明[1] 王恩元[1,2] 马亚飞[1] 何俊江 

机构地区：[1]中国矿业大学安全工程学院,江苏徐州221116 [2]煤矿瓦斯与火灾防治教育部重点实验室,江苏徐州221116 [3]永城煤电集团有限责任公司技术与信息中心,河南永城450016

出　　处：《工矿自动化》2016年第3期39-43,共5页Journal Of Mine Automation

基　　金：国家自然科学基金资助项目(51304205);教育部科学技术研究项目(113031A);中国博士后科学基金项目(2013M541982;2014T70678)

摘　　要：根据固液耦合方程与Mohr-Coulomb准则,对煤层水力压裂过程进行了数值模拟,研究了煤层裂纹扩展过程中渗流场、应力场和裂隙场("三场")的演化过程,结果表明,水力压裂过程中"三场"连续动态变化,水压力是裂隙扩展的动力,裂隙的扩展引起裂隙损伤增加、渗流场以裂隙为中心逐渐扩大、应力场逐渐分化出高应力与低应力区域,最终在主裂隙的垂直方向上形成低应力-高渗透性区域,达到卸压增透效果。Numerical simulation was conducted for hydraulic fracturing process in coal seam according to solid-liquid coupling equations and Mohr-Coulomb principle. The evolution of seepage field, stress field and fracture field （three fields） during process of crack propagation in coal seam was analyzed respectively. The results show that the three fields are changing dynamically during the process of hydraulic fracturing. The fracture is motivated to expand by pore water pressure, as a result of which, crack damage increases, seepage field centering to the fracture expands gradually, and high stress area and low stress area are developed from original stress field, and two regimes of low stress and high permeability field in a vertical direction of main fracture are ultimately formed. All of the above contribute to an effect of pressure relief and permeability improvement.

关 键 词：煤层 水力压裂 渗流场 应力场 裂隙场 “三场”演化 卸压增透 

分 类 号：TD713.3[矿业工程—矿井通风与安全]