高煤级煤储层水力压裂裂缝扩展模型研究  

Fracture extended model under hydraulic fracturing engineering for high rank coal reservoirs

作　　者：张小东[1,2] 张鹏[1] 刘浩[1] 苗书雷[1] 

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]中国矿业大学煤炭资源与安全开采国家重点实验室,北京100083

出　　处：《中国矿业大学学报》2013年第4期573-579,共7页Journal of China University of Mining & Technology

基　　金：国家自然科学基金项目(41072113);中国矿业大学煤炭资源与安全开采国家重点实验室开放基金项目(SKLCRSM10KFB01)

摘　　要：为了研究煤层气井水力压裂后的裂缝扩展规律,以沁水盆地南部煤层气井为例,基于区内煤储层的物性特征和水力压裂工程实践,根据水力压裂原理,采用数值分析的方法,探讨了研究区的煤层气井水力压裂后的裂缝形态与裂缝展布规律,提出了研究区煤层气井压裂过程中的综合滤失系数计算方法,构建了高煤级煤储层水力压裂的裂缝扩展模型,并进行了验证.研究结果表明:区内煤层气井压裂后形成的裂缝一般扩展到顶底板的泥岩中,且以垂直缝为主,裂缝形态符合KGD模型.区内常规压裂井的裂缝长为47.8～177.0m,平均90.6m.裂缝缝宽为0.013～0.049m,平均0.028m.模型计算结果与实测值、生产实践较为吻合.In order to study the extended law of coal-bed gas well after hydraulic fracturing,this study took coal-bed gas well of Qinshui basin as a case in point.Based on the physics characteristics of coal reservoirs as well as the engineering practice of hydraulic fracturing,this research used the hydraulic fracturing principle and numerical analysis to investigate the fracture morphology and fracture extended law of coal-bed gas well after hydraulic fracturing,and propose the computing method of comprehensive filtration coefficient in the process of fracturing.Besides,this study also established fracture extended model for high rank coal reservoirs during hydraulic fracturing practice,and this model was further verified.The results show that： the fractures formed by hydraulic fracturing often extend to mudstone located in the roof and the floor of coal seam,and the fractures are mainly vertical ones;the shapes of fractures conform to KGD model;the fractures’ lengths of normal hydraulic fracturing well vary from 47.8 m to 177.0 m,with an average of 90.6 m;and the fractures’ widths range from 0.013 m to 0.049 m,and with an average of 0.028 m.By the comparison,the calculation results obtained in the paper fit well with the field measured value and the actual production practice.

关 键 词：高煤级煤 水力压裂 滤失系数 裂缝扩展模型 

分 类 号：P618.1[天文地球—矿床学]