超深纹层页岩断裂韧性演化规律研究  

Study on Evolution Law of Fracture Toughness of Ultra-Deep Laminated Shale

作　　者：燕鸣飞 金衍[1,2] 韦世明 夏阳 陈勉[1,2] YAN Mingfei;JIN Yan;WEI Shiming;XIA Yang;CHEN Mian(College of Petroleum Engineering,China University of Petroleum(Beijing),Beijing,102249,China;National Key Laboratory of Petroleum Resources and Engineering,China University of Petroleum(Beijing),Beijing,102249,China)

机构地区：[1]中国石油大学(北京)石油工程学院,北京102249 [2]油气资源与工程全国重点实验室(中国石油大学(北京)),北京102249

出　　处：《石油钻探技术》2025年第2期159-167,共9页Petroleum Drilling Techniques

基　　金：国家自然科学基金重点项目“提高超深大斜度井压裂效率的关键力学问题研究”(编号:52334001);国家自然科学基金青年项目“缝洞型碳酸盐岩大斜度井裂缝非平面扩展机理研究”(编号:42407252);中国石油大学(北京)青年拔尖人才项目“超深层近井裂缝扩展转向流固耦合力学机理研究”(编号:2462023BJRC007)联合资助。

摘　　要：为深入探究超深页岩储层中水力裂缝纵向穿层机制,针对高应力及层理性质对页岩断裂特性的影响进行了系统性分析。首先,利用三轴压缩试验获取了页岩力学参数;其次,采用颗粒离散元法构建了带围压的半圆板页岩三点弯曲数值模型,模拟了页岩在不同工况下的断裂过程。数值模拟结果表明,围压增大显著提升了页岩的断裂韧性,且层理面角度和密度对断裂韧性的影响随着围压增大而增强:相同围压下,断裂韧性随着层理面角度增加而降低,随着层理面密度增加呈现小幅差异,表明层理面密度对断裂韧性的强化作用优于层理面角度。基于此,拟合了断裂韧性与围压、层理面角度和密度的定量关系,并构建了不同围压及层理面性质对页岩断裂韧性的量化图版。研究结果揭示了高应力条件下超深页岩储层层理性质对断裂特性的复杂影响,为优化水力压裂方案、有效控制水力裂缝穿层行为提供了理论依据。To explore the longitudinal hydraulic fracture propagation mechanism in ultra-deep shale reservoirs,the influence of high stress and bedding properties on shale fracture characteristics was systematically analyzed.Initially,shale mechanical parameters were obtained through triaxial compression experiments.Subsequently,a threepoint bending numerical model of a semi-circular shale plate with confining pressure was constructed using the particle discrete element method to simulate the shale fracture process under various conditions.The numerical simulation results demonstrate that increasing the confining pressure significantly enhances shale fracture toughness,and the influence of bedding plane angle and density on fracture toughness is amplified with increasing confining pressure.At the same confining pressure,fracture toughness decreases with an increase in bedding plane angle and exhibits a minor variation with an increase in bedding plane density,indicating that bedding plane density has a greater strengthening effect on fracture toughness than bedding plane angle.Based on these findings,the quantitative relationship of fracture toughness with confining pressure,bedding plane angle,and density was fitted,and a quantitative chart illustrating the impact of varying confining pressures and bedding plane properties on shale fracture toughness was developed.The results reveal the complex influence of bedding properties on fracture characteristics under high stress conditions in ultra-deep shale reservoirs,providing a theoretical basis for optimizing hydraulic fracturing schemes and effectively controlling hydraulic fracture propagation behavior.

关 键 词：超深页岩 高应力 层理面 断裂韧性 颗粒流方法 

分 类 号：TE311.2[石油与天然气工程—油气田开发工程]