页岩脆性对水力裂缝扩展特征影响的数值分析  

Numerical analysis of the influence of shale brittleness on propagation characteristics of hydraulic fractures

作　　者：李志超 杨壮壮 李培博 吴晓刚 任连伟[1] 方均 Li Zhichao;Yang Zhuangzhuang;Li Peibo;Wu Xiaogang;Ren Lianwei;Fang Jun(School of Civil Engineering,Henan Polytechnic University,Jiaozuo 454003,China;Haida Construction Group Co.,Ltd.,Ningbo 315000,China)

机构地区：[1]河南理工大学土木工程学院,河南焦作454003 [2]海达建设集团有限公司,浙江宁波315000

出　　处：《能源与环保》2025年第1期96-101,共6页CHINA ENERGY AND ENVIRONMENTAL PROTECTION

基　　金：国家自然科学基金联合基金重点项目(U23A20600);河南省重点研发与推广专项(222102320410);河南省高等学校重点科研项目计划(24B560009)。

摘　　要：页岩气资源的有效开发迫切要求在水力压裂施工时改造出复杂裂缝,针对水力裂缝的扩展特征与页岩脆性的关联问题,采用有限元数值分析方法,研究了页岩脆性对水力裂缝扩展特征的影响。研究结果表明,岩样的脆性部位相对于延性部位更容易在外荷载作用下产生裂缝,从力学分析的角度揭示了储层脆性与天然裂缝发育的关联性;水力裂缝更易在脆性矿物中扩展,且主裂缝伴生有多分支缝,利于形成复杂的压裂缝网,而延性矿物中的水力裂缝相对平直单一,且其延伸压力高于脆性矿物。研究结果揭示了高脆性页岩储层压裂成效更为显著的原因,为页岩储层可压性指标构建及高品质储层遴选提供了参考。The effective development of shale gas resources urgently requires the transformation of complex fractures during hydraulic fracturing construction.In response to the correlation between the expansion characteristics of hydraulic fractures and shale brittleness,finite element numerical analysis method was used to study the influence of shale brittleness on the expansion characteristics of hydraulic fractures.The results indicate that the brittle parts of the rock samples are more prone to cracking under external loads compared to the ductile parts,revealing the correlation between reservoir brittleness and natural crack development from a mechanical analysis perspective;hydraulic fractures are more likely to propagate in brittle minerals,and the main fracture is accompanied by multiple branching fractures,which is conducive to the formation of a complex network of hydraulic fractures.However,hydraulic fractures in ductile minerals are relatively flat and single,and their extension pressure is higher than that of brittle minerals.The research results reveal the reasons why the fracturing effect of high brittle shale reservoirs is more significant,providing reference for the construction of compressibility indicators and the selection of high-quality reservoirs in shale reservoirs.

关 键 词：水力裂缝 页岩脆性 数值分析 复杂裂缝 天然裂缝 

分 类 号：TE122.2[石油与天然气工程—油气勘探]