摘要
页岩油压裂焖井过程中,压裂液会与基质中的原油发生渗吸置换现象,可以进一步提高原油采收率。为明确鄂尔多斯盆地长7页岩油储层压裂焖井过程中不同压裂液体系的渗吸效果,将核磁共振、XRD与自发渗吸实验相结合,评价了不同压裂液体系的界面性质、渗吸效率、渗吸平衡时间以及不同孔径下渗吸特征,优选出适合于长7页岩油储层高效开发的最优压裂液体系。研究表明:研究区长7页岩油储层孔径主要分布在2 nm至20μm之间,小孔原油渗吸动用程度最大,贡献率可达13.98%;评价的8种压裂体系中,CNI-A界面张力低、渗吸平衡时间长,可有效增强原油驱动力和原油的变形能力,提高压裂焖井期间油水置换效率,渗吸采收率可达47.46%,最适于研究区长7页岩油储层。优选结果对长7页岩油储层的高效开发具有指导意义。
During the process of fracturing the formation of shale oil reservoir,the fracturing fluid will interact with the crude oil in the matrix,further improving the oil recovery.In order to determine the imbibition effect of various fracturing fluid systems in the process of fracturing and soaking shale oil reservoir of Chang 7 in Ordos Basin,the interface properties,imbibition efficiency,imbibition equilibrium time and imbibition characteristics at different pore sizes of various fracturing fluid systems were evaluated by combining NMR,XRD and spontaneous imbibition experiment.The suitable fracturing fluid system for Chang 7 shale oil reservoir in the studied area was selected.The results showed that:the pore size of Chang 7 shale oil reservoir was mainly between 0.2 nm and 20μm,and the largest oil imbibition was in the small pore with the contribution rate of 13.98%in the study area;Among the eight fracturing systems,CNI-A characterizes with low interfacial tension and long imbibition equilibrium time,could not only effectively enhance oil driving force and deformation of crude oil,but also improve the oil-water displacement efficiency.The imbibition recovery rate could reach 47.46%,and it was the most suitable fracturing fluid system for Chang 7 shale oil reservoir with the 47.46%imbibition recovery.The optimized results have guiding significance for the efficient development of Chang 7 shale oilreservoir.
作者
王毅
黄海
唐梅荣
何延龙
董凤娟
陆峰
张文通
WANG Yi;HUANG Hai;TANG Mei-rong;HE Yang-long;DONG Feng-juan;LU Feng;ZHANG Wen-tong(Shaanxi Key Laboratory of Advanced Stimulation Technology for Oil&Gas Reservoirs,School of Petroleum Engineering,Xi’an Shiyou University,Xi’an Shaanxi 710065,China;School of New Energy,Xi’an Shiyou University,Xi’an Shaanxi 710065,China;Natural Gas Evaluation Project Department of Changqing Oilfield,Xi’an Shaanxi 710021,China)
出处
《当代化工》
CAS
2023年第1期187-192,共6页
Contemporary Chemical Industry
基金
国家自然科学基金,致密砂岩油藏复杂壁面裂缝内支撑剂耦合运移铺置行为研究与模拟(项目编号:51874240)
陕西杰出青年科学基金,基于CFD-EDM耦合方法页岩油储层体积压裂支撑剂运移机制研究(项目编号:2022JC-37)
陕西高校青年创新团队项目资助。
关键词
页岩油
压裂焖井
自发渗吸
压裂液评价
Shale oil
Fracturing of soaking
Spontaneous imbibition
Fracturing fluid evaluation
