陕北低渗透储层表面活性剂驱油体系研究

针对陕北延长油田的储层情况,研制出一种以甜菜碱为主的复配驱油体系EPS,该体系配方为:甜菜碱:OP-10:异丙醇=7∶2∶1,使用浓度为0.1%。对该体系的配伍性、乳化性、抗盐性、cmc值、吸附值及采收率进行测定。结果表明,该驱油体系与陕北延长油田大部分高矿化度的地层水都有良好的配伍性和乳化性;cmc值较低(450 mg/L);岩心吸附值小(0.910 mg/g);耐盐性能好,当Ca2+浓度高达12 000 mg/L时,该体系与原油仍可达到超低界面张力(约10-3mN/m);在不同低渗透油层的驱替实验中,驱油效率提高6.7%～17.9%。

Study on surfactant flooding system of low permeability reservoir

According to the reservoir of north of Shaanxi,a betaine primarily blends with formulation flooding system EPS was developed.The formula of this system was:betaine ∶ OP-10 ∶ isopropanol was 7 ∶ 2 ∶ 1 and the concentration of the system was 0.1%.The compatibility,emulsification,salt resisting,cmc value,adsorption and oil recovery efficiency of system were determined.The experimental results demonstrated that the flooding system had good compatibility and emulsification with most oil field of high salinity formation water.The value of cmc was lower(about 450 mg/L),core adsorption was small(about 0.910 mg/g).Salt resisting was fine.When Ca2 + concentration was as high as 12 000 mg/L,this system and crude oil can still reach super-low interfacial tension(about 10-3 mN/m).In different low permeable reservoirs of displacement experiment,oil displacement efficiency increased by 6.7% to 17.9%.