砂砾岩压裂中砾石对水力裂缝扩展影响机理研究  

Research on Mechanism of Influence of Gravel on Hydraulic Crack Growth in Glutenite Fracturing

作　　者：董卓鑫 张辉[1] 艾池[2] 马旭昇 李有翼 周江浩 DONG Zhuoxin;ZHANG Hui;AI Chi;MA Xusheng;LI Youyi;ZHOU Jianghao(School of Petroleum Engineering,China University of Petroleum(Beijing),Beijing 102249,China;School of Petroleum Engineering,Northeast Petroleum University,Daqing,Heilongjiang 163318,China;NO.5 Oil Production Plant of Qinghai Oilfield CO.,Mangya,Qinghai 816499,China)

机构地区：[1]中国石油大学(北京)石油工程学院 [2]东北石油大学石油工程学院 [3]中国石油青海油田公司采油五厂

出　　处：《钻采工艺》2021年第4期57-62,共6页Drilling & Production Technology

摘　　要：近年来砂砾岩油气藏在新探明储量中占比逐年上升,砂砾岩油气藏的开发也逐渐受到重视。砂砾岩具有渗透率低、导流能力差的特性,在开发砂砾岩油藏时需要进行大规模水力压裂形成缝网,但是由于砾石阻碍复杂缝网的形成,导致砂砾岩压裂增产效果不理想。因此针对砂砾岩的结构特征,根据断裂力学理论,以砂砾岩地层中水力裂缝为研究对象,探讨在砂砾岩地层压裂时砾石对水力裂缝扩展的影响规律。研究结果表明,水力裂缝与砾石产生相互作用后,水力裂缝的扩展以绕砾石扩展为主,少数情况下会穿过砾石;砾石的形状对水力裂缝的绕砾行为具有显著影响;随着水力裂缝在绕砾过程中的扩展方向改变,水力裂缝绕砾越来越困难;砾石越圆,水力裂缝的绕砾扩展越容易。该研究进一步揭示了水力裂缝与砾石的相互作用规律,对于砂砾岩油气藏的开发有一定的借鉴意义。In recent years,the proportion of glutenite oil and gas reservoirs in newly proven reserves has increased year by year,and the development of glutenite oil and gas reservoirs has gradually received attention.Glutenite has the characteristics of low permeability and poor conductivity.Large-scale hydraulic fracturing is required to form a fracture network when developing these reservoirs.However,because gravel hinders the formation of complex fracture networks,the fracturing effect of glutenite is not ideal.Therefore,in view of the structural characteristics of glutenite and based on the theory of fracture mechanics,hydraulic fractures in glutenite formations are taken as the research object to explore the influence of gravel on the propagation of hydraulic fractures when the glutenite formation is fractured.The research results show that after the interaction between hydraulic cracks and gravel,the expansion of hydraulic cracks is mainly around the gravel,and in a few cases it will pass through the gravel.The shape of the gravel has a significant influence on the behavior of hydraulic cracks expanding around the gravel.As the expansion direction of the hydraulic crack changes during the course of expanding around the gravel,it is more and more difficult for the hydraulic crack to expand around the gravel.The smoother the shape of the gravel is,the easier it is to expand the hydraulic fracture around the gravel.This study further reveals the law of interaction between hydraulic fractures and gravel,which has certain reference significance for the development of glutenite oil and gas reservoirs.

关 键 词：水力压裂 砂砾岩 断裂力学 砾石形状 裂缝扩展 

分 类 号：TE357.1[石油与天然气工程—油气田开发工程]