低渗透油藏表面活性剂驱油体系的室内研究

The Laboratory Study on Surfactant Flooding System for Low Permeable Reservoir

关键词:  低渗透油藏  表面活性剂驱  界面张力  驱油机理  驱油效率

Key words:  low permeable reservoir  surfactant flooding  interfacial tension  flooding mechanism  oil displacement efficiency

摘要:

通过对降低界面张力能力、乳化能力、改变岩石润湿性能力、吸附量以及驱油效率的评价,研究了SHSA-03-JS表面活性剂用于江苏油田沙七断块油藏表面活性剂驱的性能,并对低渗透油藏表面活性剂驱油机理进行了探究。结果 表明,SHSA-03-JS表面活性剂溶液用于江苏油田沙七断块油藏原油时,在0.05%～0.6%浓度范围内油水界面张力均可达到10-2 mN/m的数量级,在0.1%～0.3%浓度范围内可达到10-3 mN/m的超低数量级;同时,该表面活性剂能使油湿石英片向水湿方向转变;在初始浓度0.3%时,表面活性剂在油砂的吸附量为4.78mg/g,能够满足江苏油田沙七断块表面活性剂驱的要求。室内岩心模拟驱油实验结果表明,当SHSA-03-JS表面活性剂浓度为0.3%时,表面活性剂驱可比水驱提高采收率11.47%。SHSA-03-JS表面活性剂能够满足江苏油田沙七断块进行表面活性剂驱的要求。

Abstract:

Properties of the surfactant SHSA-03-JS applied to Block 7 in Jiangsu oilfield were studied in terms of evaluation on decreasing interfacial tension capability,emulsifying capacity,changing rock wettability capability,adsorption amount and oil displacement efficiency.The flooding mechanism of surfactant flooding mechanism on low permeability reservoirs was also investigated.The results showed that the interfacial tension of SHSA-03-JS and crude oil can reach the order of 10-2mN/m with the concentration of 0.05% ～ 0.6%,and even reduced to 10-3mN/m in a concentration range of 0.1% ～ 0.3%.At the same time,the surfactant could change the oil-wet quartz to water-wet.In addition,the adsorption amount of SHSA-03-JS in Block 7 reservoir sand was 4.78 mg/g when the injection concentration was 0.3%.Lastly,the core-flooding test in lab showed that the oil displacement efficiency of surfactant flooding with 0.3% SHSA-03-JS was 11.47% higher than that of the water flooding.In brief,SHSA-03-JS could meet the requirements for surfactant flooding in Block 7,Jiangsu oilfield.