煤层及其顶、底板岩石力学性质对水力压裂裂缝延伸的控制  

Control of mechanical properties of coal seam and its roof and floor rocks over the crack extension during hydraulic fracturing

作　　者：陈同刚 汪启年[1] 朱将波 汤达祯[2] 许浩[2] CHEN Tong-gang;WANG Qi-nian;ZHU Jiang-bo;TANG Da-zhen;XU Hao(Institute of Exploration Technology of Anhui Province,Hefei 230031,China;School of Energy Resources,China University of Geosciences（Beijing）,Beijing 100083,China)

机构地区：[1]安徽省勘查技术院,合肥230031 [2]中国地质大学(北京)能源分院,北京100083

出　　处：《华东地质》2018年第3期212-217,共6页East China Geology

基　　金：国家科技重大专项"煤层气藏储渗空间特征与渗流机理研究(编号:2011ZX05038-001)";国家自然科学基金(编号:41272175)项目联合资助

摘　　要：为了揭示煤层及其顶、底板岩石力学性质对水力压裂裂缝延伸的影响,应用岩石三轴伺服机测试陕西韩城地区煤层及顶、底板岩石力学性质,总结不同类型岩石力学性质特征和差异;剖析孔隙率和含水率与岩石力学性质之间的关系,探讨岩石力学性质差异对煤层水力压裂的影响。研究表明:岩石强度随孔隙度增大而降低;岩石矿物成分及其胶结程度与孔隙度决定岩石的软化程度,水分对不同类型岩石强度的影响方式和程度差异较大;当煤层埋藏较浅,煤层与顶、底板岩石的弹性模量存在较大差异时,水力压裂裂缝更易控制在煤层中,且延伸更长更远。In order to reveal the influence of mechanical properties of coal seam and its roof and floor rocks on crack extension during hydraulic fracturing, rock three-axis stress was used to test rock mechanical properties of various coal seams and their roof, floor rocks in the Hancheng area, Shaanxi Province. Characteristics and differences of mechanical properties of various rocks are summarized in this study. Through analyzing the relationships between porosity and water content, we explored influences of the differences of mechanical properties on fracture extension. The testing results show that rock strength decreases with increasing porosity, rock softening property depends on mineral compositions and rock porosity, and water contents greatly affect the strength of various rocks in different ways. For a shallowly-buried coal seam, roof and floor rocks of which have significant differences in elastic modulus, hydraulic cracking can be easily restricted within coal seam but extends much further.

关 键 词：煤层 煤层顶、底板 岩石力学性质 裂缝 

分 类 号：TE37[石油与天然气工程—油气田开发工程] TD313[矿业工程—矿井建设]