煤岩水力压裂起裂压力和裂缝扩展机制实验研究  

Experimental study on initiation pressure and mechanism of fracture propagation of hydraulic fracturing in coal and rock mass

作　　者：张帆[1] 马耕[1,2,3] 刘晓 冯丹[4] 

机构地区：[1]河南理工大学能源科学与工程学院,河南焦作454003 [2]河南能源化工集团研究院有限公司,河南郑州450046 [3]中原经济区煤层(页岩)气河南省协同创新中心,河南焦作454003 [4]重庆大学煤矿灾害动力学与控制国家重点实验室,重庆400044

出　　处：《煤田地质与勘探》2017年第6期84-89,共6页Coal Geology & Exploration

基　　金：河南省教育厅科学技术研究重点项目(13A440320);2014年度安全生产重大事故防治关键技术重点科技项目(Henan-066-2013AQ);2015年安全生产重大事故防治关键技术重点科技项目(Henan-0007-2015AQ)~~

摘　　要：为了研究煤岩水力压裂的起裂压力和水力压裂裂缝扩展规律,采用型煤试样,利用自主研发的水力压裂实验系统,参照现场压裂施工制定了"施加三向应力–顶部注水"的煤岩水力压裂物理模拟实验方案并开展了水力压裂实验,分析了不同条件下泵注压力和水力压裂裂缝。实验结果表明:压裂液泵注排量越大,起裂压力越大。三向应力满足最大水平主应力σH>垂向应力σv>最小水平主应力σh,水力压裂裂缝沿着垂直于σh的方向扩展。σv和σh一定,随着σH的增大,煤岩起裂压力先增大后减小,水力压裂裂缝扩展路径越平直。当σH远大于σv和σh时,水力压裂裂缝扩展路径越复杂,分叉缝角度越大。研究结果可为煤岩水力压裂理论的完善提供一定的参考和借鉴。To study the hydraulic fracturing initiation pressure and mechanism of fracture propagation in coal and rock mass, the physical simulation experiment program ＂exerting three-dimensional stresses-injecting fluid from the top＂ of coalbed hydraulic fracturing was established based on engineering applications by using briquette samples and self-developed hydraulic fracturing testing system. According to the above program combining the existing experimental conditions, the water pressure and hydraulic fracture were analyzed under varied conditions. The experimental results show that initiation pressure increases in the process of increasing flow rate. Hydraulic fractures propagate along the direction perpendicular to σh under the condition of σHσvσh. With the increase of σH, the initiation pressure of coal rock increases at first and then decreases when σv and σh are constant, in addition, the fracture propagation path becomes more straight. As σH is much larger than σv and σh, the fracture propagation path gets more complex and the angle of bifurcate fractures is larger. The results are of significance and importance for the improvement of hydraulic fracturing theory in coal rock mass.

关 键 词：煤岩 真三轴 水力压裂 起裂压力 裂缝扩展 物理模拟 

分 类 号：TD313[矿业工程—矿井建设]