粗糙裂缝内支撑剂运移与展布规律数值模拟  

Numerical Simulation of Migration and Placement Law of Proppants in Rough Fractures

作　　者：刘善勇[1,2,3] 尹彪 楼一珊 张艳[1,2,4] LIU Shanyong;YIN Biao;LOU Yishan;ZHANG Yan(Hubei Key Laboratory of Drilling and Production Engineering for Oil and Gas,Yangtze University,Wuhan,Hubei,430100,China;National Engineering Research Center for Oil&Gas Drilling and Completion Technology,Yangtze University,Wuhan,Hubei,430100,China;Institute of Mud Logging Technology and Engineering,Yangtze University,Jingzhou,Hubei,434023,China;School of Petroleum Engineering,Yangtze University,Wuhan,Hubei,430100,China)

机构地区：[1]油气钻采工程湖北省重点实验室(长江大学),湖北武汉430100 [2]油气钻完井技术国家工程研究中心(长江大学),湖北武汉430100 [3]长江大学录井技术与工程研究院,湖北荆州434023 [4]长江大学石油工程学院,湖北武汉430100

出　　处：《石油钻探技术》2024年第4期104-109,共6页Petroleum Drilling Techniques

基　　金：油气钻采工程湖北省重点实验开放基金项目“深部低渗储层粗糙裂缝内支撑剂运移与展布行为机理研究”(编号:YQZC202410)、中国海洋石油有限公司“十四五”重大科技项目“海上低渗及潜山油气田有效开发技术”(编号:KJGG2022-0701)联合资助。

摘　　要：粗糙狭窄裂缝壁面造成水力压裂有效裂缝体积减小,极大地影响缝内支撑剂运移与铺置和压裂改造效果。为此,采用Matlab建立自相关高斯分布曲面,并结合分形理论识别分析裂缝粗糙面,采用计算流体动力学—颗粒元(CFD-DEM)双向耦合方法,建立了不同粗糙度的裂缝三维模型,分析了不同支撑剂粒径组合在不同粗糙度缝道内的沉积和运移过程及规律。研究表明:随着缝面由平滑向粗糙变化,支撑剂堵塞明显;在重力作用下小粒径支撑剂(粒径与缝宽比为0.3)具有出更好的运移能力,但难以保证近井端支撑效果;大粒径支撑剂(粒径与缝宽比为0.8)覆盖面积增加158.1%,堵塞于缝口附近,影响后续支撑剂向远处运移,推荐粒径缝宽比为0.4;对于组合粒径加砂方式,推荐采用“先小后大”的注入顺序,以保证支撑剂运移距离和效率。研究结果有助于更好地理解裂缝粗糙度对支撑剂在裂缝中运移的影响,对压裂设计及施工参数优化具有指导意义。The rough and narrow fracture walls reduce the effective fracture volume of hydraulic fracturing,which greatly affects the migration and placement of proppants in the fractures and the effect of fracturing stimulation.Therefore,the self-correlated Gaussian distribution surface was established by Matlab,and the rough fracture surface was identified and analyzed with fractal theory.The bidirectional coupling of the computational fluid dynamicsdiscrete element method(CFD-DEM)was employed to build three-dimensional models of fractures with different roughness,and the deposition and migration process and law of different combinations of proppant diameters within the rough fracture channels were investigated.The research findings indicate that as the fractured surface transitions from smooth to rough,proppant plugging becomes more evident.Under the influence of gravity,small-sized proppants(ratio of diameter to fracture width of 0.3)exhibit better migration capabilities but struggled to ensure the near-wellbore supporting effect.The area covered by large-sized proppants(ratio of diameter to fracture width of 0.8)increase by 158.1%,but the proppant is blocked near the fracture end,affecting subsequent proppant migration to distant areas.Therefore,the recommended ratio of diameter to fracture width is 0.4.For the sand addition method with combined particle diameters,it is recommended to inject small-sized sand first and then large-sized sand to ensure the proppant migration distance and efficiency.The research outcomes contribute to a better understanding of the influence of fracture roughness on proppant migration within fractures, providing important guidance for optimizing fracturingdesign and operation parameters.

关 键 词：水力压裂 计算流体动力学 颗粒元 粗糙裂缝 粗糙度 支撑剂运移 

分 类 号：TE357.12[石油与天然气工程—油气田开发工程]