鄂尔多斯盆地长7页岩储层压裂液渗吸规律及原油微观动用特征  

Imbibition of fracturing fluid and microscopic oil production characteristics in Chang 7 shale reservoir in Ordos Basin

作　　者：王琛[1,2] 高辉 费二战[3] 刘斌 王科懿 李腾[1,2] 刘月亮 WANG Chen;GAO Hui;FEI Erzhan;LIU Bin;WANG Keyi;LI Teng;LIU Yueliang(School of Petroleum Engineering,Xi̍an Shiyou University,Xi̍an 710065,China;Xi̍an Key Laboratory of Tight Oil(Shale Oil)Development,Xi̍an 710065,China;No.3 Oil Production Plant,PetroChina Changqing Oilfield Company,Yinchuan 750005,China;No.8 Oil Production Plant,PetroChina Changqing Oilfield Company,Xi̍an 710018,China;No.10 Oil Production Plant,PetroChina Changqing Oilfield Company,Qingyang 740051,China;College of Petroleum Engineering,China University of Petroleum(Beijing),Beijing 102249,China)

机构地区：[1]西安石油大学石油工程学院,陕西西安710065 [2]西安市致密油(页岩油)开发重点实验室,陕西西安710065 [3]中国石油长庆油田分公司第三采油厂,宁夏银川750005 [4]中国石油长庆油田分公司第八采油厂,陕西西安710018 [5]中国石油长庆油田分公司第十采油厂,陕西庆阳740051 [6]中国石油大学(北京)石油工程学院,北京102249

出　　处：《中国石油大学学报（自然科学版）》2023年第6期95-103,共9页Journal of China University of Petroleum(Edition of Natural Science)

基　　金：陕西省重点研发计划(2023-YBGY-306,2022GY-137);陕西省教育厅重点科学研究计划项目(22JY054);陕西省教育厅青年创新团队建设科研计划项目(21JP095);陕西高校青年创新团队项目。

摘　　要：为揭示鄂尔多斯盆地长7页岩油藏压裂液渗吸排油规律,评价渗吸阶段原油微观动用特征,选取典型的互层状页岩和厚层状页岩岩心样品,利用低场核磁共振技术结合室内高温高压渗吸模拟装置,开展页岩油藏压裂液渗吸排油室内动态模拟实验,定量评价页岩油藏压后渗吸阶段,不同尺度孔喉的压裂液渗吸速度、渗吸采收率及原油微观动用特征。结果表明,页岩油藏压裂液渗吸过程可分为高速渗吸阶段和稳定渗吸阶段,渗吸作用前6 h是高效渗吸阶段,此时的渗吸速率最高可以达到3.08%/h;互层状页岩储层的较小孔喉的渗吸速率及渗吸采收率显著高于较大孔喉,较小孔喉对渗吸采收率的贡献程度可达到81.18%;厚层状页岩压裂液在不同尺度孔喉中的渗吸采收率接近。在页岩油藏压裂阶段,页岩储层渗透率和黏土矿物含量是影响压裂液渗吸效果的主要控制因素,相关成果及认识可为页岩油藏压裂方案优化提供理论支撑。In order to reveal the imbibition displacement behaviour of fracturing fluid in Chang 7 shale reservoir in Ordos Ba-sin and evaluate the microscopic oil production characteristics in imbibition stage,core samples of interbedded shale and thick bedded shale were selected to carry out experiments using a low-field nuclear magnetic resonance technique and an in-door high temperature and high pressure imbibition simulation device.The imbibition rate and imbibition efficiency of fractu-ring fluid and the microscopic oil production characteristics at different pore throat scales were quantitatively evaluated in the post-pressure imbibition stage of the shale reservoir after fracturing.The experimental results show that the imbibition process of fracturing fluid in shale reservoir can be divided into high-speed imbibition stage and stable imbibition stage.The imbibi-tion rate of fracturing fluid in the shale reservoir can reach up to 3.08%/h at 6 hours before imbibition.The imbibition rate and imbibition efficiency of small pore throats in interbedded shale reservoir are significantly higher than those of large pore throats,and the contribution of small pore throats to the total imbibition efficiency can reach to 81.18%.The imbibition effi-ciency of thick layered shale in different pore throat scales is similar.In the fracturing stage of the shale reservoir,the perme-ability and clay mineral content of the shale reservoir are the main control factors affecting the imbibition effect of fracturing fluid.The relevant results and understanding obtained in this study can provide theoretical support for the optimization of fracturing scheme of shale reservoirs.

关 键 词：渗吸速率 渗吸采收率 压裂液渗吸 核磁共振技术 长7页岩油藏 

分 类 号：TE349[石油与天然气工程—油气田开发工程]