不同因素对水力压裂促抽煤层瓦斯的影响  

Influences of different factors on enhancing methane drainage by hydraulic fracturing

作　　者：范超军[1] 李胜[1] 兰天伟[1] 罗明坤[1] 杨振华[1] 陶梅[1] 

机构地区：[1]辽宁工程技术大学矿业学院,辽宁阜新123000

出　　处：《中国安全科学学报》2017年第12期97-102,共6页China Safety Science Journal

基　　金：国家重点研发计划(2016YFC0801407-2);国家自然科学基金资助(51674132;51604139);辽宁省自然科学基金资助(2015020614);辽宁省教育厅城市研究院项目(LJCl002)

摘　　要：为揭示不同因素对水力压裂促进煤层瓦斯抽采的影响,保障煤矿安全开采,基于多物理场耦合理论,建立包含损伤场、应力场和渗流场的煤层压裂和抽采统一数学模型,运用Comsol联合Matlab软件求解,结合现场试验,验证统一数学模型的有效性,并模拟分析钻孔间距、注水压力、煤体弹性模量和地应力等因素对水力压裂及瓦斯抽采过程的影响。结果表明:现场试验与模拟得出的压裂贯通时间较吻合;压裂损伤区在抽采孔处贯通是有效抽采煤层瓦斯的关键;压裂贯通时间与煤层弹性模量成线性增加关系,与垂直地应力、钻孔间距成指数增加关系,与注水压力成指数降低关系。To make clear the influences of different factors on enhancing methane extraction by hydraulic fracturing in coal seam,and ensure the safe mining of coal mine,a unified mathematical model was built for hydraulic fracturing and gas drainage based on the multiphysics coupling theory,involving a hydraulic field,a mechanical field and a damage field. The processes of hydraulic fracturing and gas drainage were simulated by Comsol with Matlab software. The effectiveness of the model was verified by the data obtained in the field test. The influences of borehole-to-borehole spacing,water injection pressure,coal elasticity modulus and in-situ stress on fracturing were quantitatively analyzed. Results show that the fracture breakthrough time of numerical simulation is in good agreement with that obtained in the field test,that the key to effective gas drainage is that the fracturing damage zone can be connected at the drainage borehole,that the fracture breakthrough time increases linearly with elastic modulus and homogeneity of coal seam,increases exponentially with vertical stress and borehole-to-borehole spacing,and decreases exponentially with injected water pressure.

关 键 词：水力压裂 瓦斯抽采 煤层增透 影响因素 数值模拟 

分 类 号：X936[环境科学与工程—安全科学]