非常规储层压裂支撑剂多级裂缝运移和沉降规律  

Migration and settlement laws of proppant in multi-scale fractures during the fracturing in the unconventional reservoirs

作　　者：汪杰[1,2,3] 赵康佳 付珊珊 续化蕾 张良君 江厚顺 WANG Jie;ZHAO Kangjia;FU Shanshan;XU Hualei;ZHANG Liangjun;JIANG Houshun(Cooperative Innovation Center of Unconventional Oil and Gas//Yangtze University,Wuhan,Hubei 430100,China;College of Petroleum Engineering,Yangtze University,Wuhan,Hubei 430100 China;Hubei Key Laboratory of Drilling and Production Engineering for Oil and Gas,Wuhan,Hubei 430100,China)

机构地区：[1]非常规油气省部共建协同创新中心•长江大学 [2]长江大学石油工程学院 [3]油气钻采工程湖北省重点实验室

出　　处：《天然气工业》2024年第7期109-119,共11页Natural Gas Industry

基　　金：国家自然科学基金面上项目“页岩气藏压窜形成机理及暂堵转向对策研究”(编号:52274028);非常规油气省部共建协同创新中心(长江大学)开放基金“低渗透油藏降压增注剂作用机理及关键影响因素研究”(编号:UOG2024-04);湖北省自然科学基金-面上类型项目(青年)“纳米排驱剂解除涪陵页岩气藏水锁损害机理研究”(编号:2021CFB249)。

摘　　要：水力压裂过程中支撑剂在裂缝中有效填充是形成高导流裂缝通道的关键。目前,关于支撑剂在裂缝中运移与沉降规律的研究方法多为物理实验或数值模拟,且主要聚焦支撑剂沉降结果,对支撑运移和沉降机理的研究较少。为进一步揭示支撑剂在裂缝中的运移和沉降规律,采用实验与数值模拟结合的方法探究了支撑剂尺寸、注入速度以及压裂液黏度对支撑剂在单一与交叉裂缝中的运移沉降行为的影响。研究结果表明:①支撑剂尺寸主要通过对沉降角的影响决定颗粒运移的分布,支撑剂尺寸越大,颗粒沉降角越大,运移距离越短;②注入速度对砂丘形态影响较大,当注入速度从0.2m/s增加至1.0m/s时,单一裂缝内砂丘有效支撑面积比和最大高度都明显降低,而分支缝内砂丘有效支撑面积比增加34.3%,表现出与单一裂缝中相反的变化趋势;③压裂液黏度主要影响流体携砂能力,随着压裂液黏度增加,主裂缝内砂丘有效支撑面积比降低8.4%,砂丘最大高度下降6.1cm,而在分支裂缝内表现为先增加后降低。结论认为,分支裂缝与主裂缝内支撑剂运移受施工因素影响往往表现出不同变化规律,该研究成果将进一步完善了水力压裂相关理论认识,同时为压裂现场施工设计优化提供了理论支撑。The effective proppant packing in fractures is crucial to the formation of high-conductivity fracture channels during hydraulic fracturing.At present,the researches on proppant migration and settlement laws in fractures are mainly performed by means of physical experiment or numerical simulation,and mainly focus on the results of proppant settlement,but with less emphasis on the mechanisms of proppant migration and settlement.To gain further insights into proppant migration and settlement laws in fractures,this paper combines experiment with numerical simulation to study the influences of proppant size,injection velocity and fracturing fluid viscosity on the migration and settlement behaviors of proppant in single and cross fractures.The following research results are obtained.First,proppant size controls the distribution of particle migration mainly by influencing settlement angles.The larger the proppant size,the larger the settlement angle and the shorter the migration distance.Second,injection velocity has a great influence on the shape of the sand dune.When the injection velocity increases from 0.2 m/s to 1.0 m/s,the effective supporting area ratio and maximum height of sand dune in a single fracture decrease significantly,while the effective supporting area ratio of sand dune in a branch fracture increases by 34.3%,showing an opposite trend to that in a single fracture.Third,fracturing fluid viscosity mainly affects the sand-carrying capacity of the fluid.With the increase of fracturing fluid viscosity,the effective supporting area ratio and maximum height of sand dune decrease by 8.4%and 6.1 cm in the main fracture,but increases first and then decreases in the branch fracture.In conclusion,proppant migration in branch fractures and main fractures often shows different laws under the influence of operation factors.The research results will further improve the theoretical understanding of hydraulic fracturing and provide theoretical support for the optimization of fracturing operation design.

关 键 词：非常规油气 水力压裂 分支裂缝 交叉裂缝 支撑剂运移沉降 施工因素 室内实验 数值模拟 

分 类 号：TE37[石油与天然气工程—油气田开发工程]