摘要
针对胜坨油田高温高盐、水驱采收率低问题,开展适合胜坨油田二区油藏条件自发乳化驱油配方研究.采用乳化能力测试和油/水界面张力测量,对自发乳化驱油体系中的碱、表面活性剂的种类及质量浓度进行优化,并结合物模实验对优选出的配方进行驱油效果评价.结果表明:复合碱和表面活性剂的协同作用使油/水界面张力达到超低,并导致油滴在轻微界面扰动作用下自发乳化;表面活性剂静态吸附量较小,且油砂上的吸附量小于净砂上的吸附量;均质模型中,自发乳化体系与残余油在多孔介质剪切作用下形成乳状液,依靠乳状液液滴堵塞大孔喉产生的贾敏效应和分流作用,提高波及系数,同时伴随油带的形成,自发乳化驱的采收率在水驱基础上提高25%;非均质模型中,形成的乳状液不足以有效封堵高渗通道,而是被驱替液携带流出地层,驱油效果变差.
This work is aimed at the problems of high temperature and high salinity of Shengtuo oilfield and its low oil recovery by waterflood.We develop spontaneous emulsification flooding formula which adapt to reservoir condition of Shengtuo oilfield.A serious of emulsification tests and oil/water interfacial tension measurements were conducted to screen alkali,surfactant type and concentration of spontaneous emulsification flooding system.The results showed that the interfacial tension of oil/water could be low-ered to an ultralow level by synergistic effect combined alkaline and surfactant,leading to easy spontaneous emulsificationof oil under slightinterfacial disturbance.Its static adsorptionislittle,which on the oil sand is lower than the clean sand.The results of sandpack flood tests suggested that spontaneous emulsification system and residual oil could form emulsion under the shearing action of porous media in the homogenous sandpack,depended on emulsion droplets generated Jamin effect and shunt effect by plugging large pore throat,which improved the sweep efficiency and produced oil zone at the same time.The tertiary oil recovery increased by 25% by injecting a 0.8pore volume(PV)of alkali/surfactant slug.Emulsion droplets formed in the heterogeneoussandpacksare insufficient to plug water channel effectively and entrained out of formation with the displacing fluid,result in lower oil displacement efficiency.
出处
《东北石油大学学报》
CAS
北大核心
2014年第6期76-84,9-10,共9页
Journal of Northeast Petroleum University
基金
国家科技重大专项(2011ZX05011)
长江学者和创新团队发展计划项目(IRT1294)
关键词
自发乳化
界面扰动
波及系数
采收率
贾敏效应
胜坨油田
spontaneous emulsification
interfacial disturbance
sweep efficiency
tertiary oil recovery
Jamin effect
Shengtuo oilfield
