页岩气藏水平井多级水力压裂方法优选  

Optimization of multistage hydraulic fracturing method of horizontal wells in shale gas reservoirs

作　　者：薛明宇 程远方[1] 闫传梁 李阳[1] 李庆超 韩松财 XUE Mingyu;CHENG Yuanfang;YAN Chuanliang;LI Yang;LI Qingchao;HAN Songcai(College of Petroleum Engineering, China University of Petroleum, Qingdao 266580, China)

机构地区：[1]中国石油大学(华东)石油工程学院,山东青岛266580

出　　处：《大庆石油地质与开发》2020年第6期152-159,共8页Petroleum Geology & Oilfield Development in Daqing

基　　金：国家自然科学基金重点支持项目“超深层天然气藏开发基础理论研究”(U1762216)。

摘　　要：水平井多级水力压裂是有效开发页岩气藏的必要技术手段。针对页岩气藏水平井多级水力压裂过程中不同压裂方法对裂缝扩展的影响问题,利用有限元模拟软件建立了在基于黏聚单元方法的扩展有限单元法架构下的二维流-固耦合模型,模拟分析了5种不同压裂施工方案对裂缝扩展的影响规律。结果表明:同步法压裂对储层改造的体积较小;两步法压裂和顺序法压裂会导致近井筒处裂缝过度闭合,不利于后续开采作业;反两步法压裂和交替顺序法压裂可以有效降低应力干扰的影响,增加储层改造体积。模拟结果表明了不同压裂方法对储层改造效果的影响,并认为反两步法压裂为最优化多级水力压裂方法。研究成果为页岩气藏水平井压裂提供了新的思路,对典型的现场应用具有指导意义。Multistage hydraulic fracturing of horizontal wells is the necessary technology to effectively develop shale gas reservoirs.Aimed at the influence of different fracturing methods on the fracture propagation in horizontal wells of shale gas reservoirs during multistage hydraulic fracturing,with the help of the finite element simulating software,the 2D liquid-solid coupling model was established based on the extended finite element method(XFEM)of the cohesive element method.The influencing laws of five different fracturing operation programs on the fracture propagation were simulated and analyzed.The results show that for the simultaneous fracturing,the simulated reservoir volume is small;for two-step fracturing and sequential fracturing,the excessive closure of the fractures near the wellbore is easy to occur,which is not conducive to the subsequent production;for the reverse two-step fracturing and alternative sequential fracturing,the influence of the stress interference will be effectively reduced,thus the simuleted reservoir volume will be increased.These simulated results show that different fracturing methods have diverse effects on the reservior simulation,of which the reverse two-step fracturing was found to be the optimal multistage hydraulic fracturing method.All these achievements have provided a new thinking of the horizontal-well hydraulic fracturing in shale gas reservoirs,and presented the guiding significance for the typical field application.

关 键 词：页岩气藏 多级水力压裂 压裂方法 应力干扰 数值模拟 

分 类 号：TE357.1[石油与天然气工程—油气田开发工程]