摘要
微乳液因其良好降低油水界面张力、润湿改变、增溶、热稳定等优势,在低渗透油藏具有较大应用潜力。文章以长庆油田长3区块低渗透油藏为例,通过微乳液微观形貌测定、粒径分析、界面张力测定、原油组分增溶及润湿性测试,系统评价了现场应用微乳液体系的储层适应性能,并借助核磁共振在线驱替系统对其驱油潜力进行了探究。研究结果表明,该微乳液为水包油(O/W)型,平均粒径约为13 nm,可有效适应低渗透储层微纳米级孔隙喉道,可降低油水界面张力至1.71 mN/m,界面模量会随振荡频率增加而提升,油藏温度下老化20 d后,微乳液的粒径、界面张力等趋于稳定,油相增溶参数达36 mL/g,尤其对饱和分与芳香分表现出更优的增溶效果,水下油滴接触角从164°降至55°,实现了油湿向水湿润湿性转变。核磁共振在线驱替实验进一步揭示,注入1.0 PV微乳液体系可有效提高采收率10.86个百分点,同时使驱替压力降低24.87%,表现出显著的降压增注效果。微乳液具有较大增油潜力,为其在长庆油田低渗透油藏的扩大规模化应用提供重要数据支撑。
Microemulsion exhibits significant application potential in low-permeability reservoirs owing to its superior capabilities in reducing oil-water interfacial tension,altering wettability,enhancing solubilization,and maintaining thermal stability.Taking the low permeability reservoir in Block Chang-3 of Changqing oilfield as an example,the reservoir adaptability of the field application of microemulsion system was systematically evaluated by means of microemulsion micromorphology measurement,particle size analysis,interfacial tension measurement,crude oil component solubilization and wettability test,and its oil displacement potential was explored by means of nuclear magnetic resonance online displacement system.The experimental results demonstrated that the microemulsion exhibited an oil-in-water(O/W)structure with an average particle size of approximately 13 nm,which could effectively match with the micro-nano pore throat of low permeability reservoir.Notably,this system achieved significant interfacial activity,reducing oil-water interfacial tension to 1.71 mN/m,while the interfacial modulus increased with rising oscillation frequency.After 20 days of aging at the reservoir temperature,the key parameters including particle size and interfacial tension kept stable,while the microemulsion demonstrated exceptional solubilization capacity with an oil solubilization parameter reaching 36 mL/g,particularly,the enhanced solubilization effects were observed for saturated and aromatic fractions.Furthermore,the system effectively altered reservoir wettability,as evidenced by the substantial decrease in underwater oil droplet contact angle from 164°to 55°,indicating a successful transition from oil-wet to water-wet conditions.The nuclear magnetic resonance online flooding experiments further revealed that injection of 1.0 PV of the microemulsion enhances oil recovery by 10.86 percentage point while reduced displacement pressure by 24.87%,demonstrating significant pressure reducing and injection enhancing effects.The experimental results revealed that the microemulsion system exhibited considerable potential for enhanced oil recovery,providing crucial technical support for its large-scale field application in low-permeability reservoirs of Changqing oilfield.
作者
李佳潞
刘云龙
闫宁
王腾
吕东方
赵文景
陈佳
赵光
LI Jialu;LIU Yunlong;YAN Ning;WANG Teng;LYU Dongfang;ZHAO Wenjing;CHEN Jia;ZHAO Guang(School of Petroleum Engineering,China University of Petroleum(East China),Qingdao,Shandong 266580,China;State Key Laboratory of Deep Oil and Gas,China University of Petroleum(East China),Qingdao,Shandong 266580,China;Oil and Gas Technology Research Institute,Changqing Oilfield Branch Company,PetroChina,Xi’an,Shaanxi 710018,China)
出处
《油田化学》
北大核心
2026年第1期115-124,共10页
Oilfield Chemistry
基金
国家自然科学基金联合基金重点项目“海上稠油CO_(2)反应增黏聚表剂驱油体系构建及作用机制”(项目编号U23B2087)。
关键词
低渗透油藏
微乳液
润湿性转变
核磁共振
降压增注
low-permeability reservoirs
microemulsion
wettability transition
nuclear magnetic resonance
pressure reduction and injection enhancement
