基于离散元方法的层理发育地层水力裂缝扩展规律  

Hydraulic Fractures Propagation in Bedding Developed Stratum Based on Distinct Element Method

作　　者：李建民 佟亮 贾海正 王俊超 张腾 郑永香 LI Jian-min;TONG Liang;JIA Hai-zheng;WANG Jun-chao;ZHANG Teng;ZHENG Yong-xiang(Engineering Technology Research Institute of Xinjiang Oilfield Company,Karamay 834000,China;YuanWangJingSheng Technology(Beijing)Co.,Ltd.,Beijing 100083,China;School of Civil Engineering,Shijiazhuang Tiedao University,Shijiazhuang 050043,China)

机构地区：[1]新疆油田公司工程技术研究院,克拉玛依834000 [2]北京远望景盛科技发展有限公司,北京100083 [3]石家庄铁道大学土木工程学院,石家庄050043

出　　处：《科学技术与工程》2023年第13期5515-5521,共7页Science Technology and Engineering

基　　金：中国石油天然气股份有限公司重大现场攻关项目子课题(2020CGCG006);河北省自然科学基金青年项目(E2021210036)。

摘　　要：层理发育是页岩储层的典型特征,水力裂缝能否穿过层理面继续扩展决定了裂缝形态的复杂程度,其中层理强度是影响水力裂缝穿层行为的关键因素。为了探究层理强度对水力裂缝穿层行为的影响,采用块体离散元方法,分别计算了层理面的抗剪强度(黏聚力)和抗拉强度对水力裂缝在层状地层内扩展行为的影响。结果表明,水力裂缝遇到水平层理后的形态可分为转向层理面扩展和继续竖向扩展两种类型。层理面强度对水力裂缝的穿层能力具有显著影响,当层理面的抗拉强度和抗剪强度均较低时,水力裂缝的穿层能力差,水力裂缝不能穿过层理;当层理面的抗拉强度和抗剪强度均较高时,水力裂缝的穿层能力增强,水力裂缝穿过层理面扩展;当层理面的某一个强度较低时(抗拉或抗剪),则低强度因素成为主控因素,另一强度参数的增加不会改变水力裂缝的穿层能力。厘清了层理强度对水力裂缝穿层行为的影响,对层理发育地层的水力压裂施工具有重要的理论指导意义。The bedding is relatively developed in shale reservoir.And the bedding has an important influence on the propagation of hydraulic fractures.In order to explore the influence of the deformation parameters and bedding strength on the behavior of hydraulic fractures penetrating through the stratum,shear strength and tensile strength of the bedding plane were calculated by the block discrete element method.The results show that the hydraulic fractures behavior can be divided into two types after encountering horizontal bedding plane.The bedding-penetrating ability of hydraulic fractures was controlled by the strength of bedding plane.When the tensile strength and shear strength of the bedding plane are both low,the penetration ability of hydraulic fractures is poor,and hydraulic fractures cannot penetrate the bedding plane.When the tensile strength and shear strength of the bedding plane are both high,the bedding-penetration ability of the hydraulic fracture is enhanced,and the hydraulic fracture propagates through the bedding plane.When one of strength of the bedding plane is low(tensile or shear),it becomes the main control factor,and the increase of another strength will not change the bedding-penetration ability of hydraulic fractures.The research clarifies the influence of bedding strength on the hydraulic fracturing behavior,which has important theoretical significance for the hydraulic fracturing construction of the bedding developed formation.

关 键 词：水力压裂 裂缝穿层行为 层理强度 层理弱面 块体离散元 

分 类 号：TE357[石油与天然气工程—油气田开发工程]