摘要
在页岩缝内暂堵压裂中,暂堵通过优化裂缝的流体流动路径并促进新分支的形成,从而提高压裂效率。然而,当前关于暂堵颗粒精准输运至目标区域并有效沉积的研究仍显不足。为明确页岩缝内暂堵颗粒输运特征,基于计算流体力学(computational fluid dynamics,CFD)-离散单元模型(discrete element method,DEM)CFD-DEM耦合模型,结合流体动力学与离散单元法,分析了泵入排量、压裂液黏度、粒径及加砂强度对暂堵颗粒运移沉降规律的影响。结果表明:较高排量促进颗粒达到裂缝远端并形成稳定封堵层,从而提升暂堵效率;黏度较低的压裂液可显著提高颗粒沉降速度,促进颗粒在裂缝中的均匀分布,并有效提升沉降覆盖率,从而增强封堵效果;粒径增大时,颗粒平均速度逐渐降低,而较小粒径更容易在裂缝尖端聚集沉积,形成致密屏障并改善导流性;加砂强度的增加显著提升颗粒输运速率和接收质量,对缝口区域影响显著,同时提高运输效率并缩短施工时间。经现场验证,研究成果对提升页岩缝内暂堵压裂效率具有重要应用价值。
In the process of temporary plugging fracturing in shale fractures,temporary plugging enhances the fracturing efficiency by optimizing the fluid flow path of fractures and promoting the formation of new branches.However,current research on the precise transport of temporary plugging particles to the target area and their effective deposition is still insufficient.To clarify the transport characteristics of temporary plugging particles in shale fractures,combining fluid dynamics and discrete element method,a CFD-DEM(computational fluid dynamics-discrete element method)coupled model was used,to analyze the influence of pump injection rate,fracturing fluid viscosity,particle size,and proppant intensity on the transport and sedimentation laws of temporary plugging particles.The results show that a higher injection rate promotes the transport of particles to the far end of the fracture and the formation of a stable plugging layer,thereby improving the temporary plugging efficiency;A lower viscosity fracturing fluid can significantly increase the sedimentation speed of particles,promote their uniform distribution in the fracture,and effectively increase the sedimentation coverage rate,thereby enhancing the plugging effect;As the particle size increases,the average particle velocity gradually decreases,while smaller particle sizes are more likely to accumulate and deposit at the fracture tip,forming a dense barrier and improving the conductivity;An increase in proppant intensity significantly enhances the particle transport rate and reception quality,with a significant impact on the fracture mouth area,while improving the transport efficiency and shortening the construction time.Field verification shows that the research results of this paper have important application value for improving the efficiency of temporary plugging fracturing in shale fractures.
作者
李政澔
孔祥伟
陈明忠
陈青
徐敏
石博玮
LI Zheng-hao;KONG Xiang-wei;CHEN Ming-zhong;CHEN Qing;XU Min;SHI Bo-wei(School of Petroleum Engineering,Yangtze University,Wuhan 430100,China;Hubei Key Laboratory of Drilling and Production Engineering for Oil&Gas,Wuhan 430100,China;CCDC Downhole Service Company,Chengdu610000,China)
出处
《科学技术与工程》
北大核心
2025年第23期9777-9784,共8页
Science Technology and Engineering
基金
中石油川庆钻探工程有限公司项目(CQCJ-2001-06)。
关键词
页岩
缝内暂堵
CFD-DEM耦合
暂堵颗粒运移
封堵
shale
temporary plugging within the seam
CFD-DEM coupling
temporary plugging particle migration
blockade
