聚合物驱后石油磺酸盐体系提高采收率室内实验研究

A laboratory study of enhancing oil recovery with petroleum sulfonant system after polymer flooding

针对孤岛油田中一区Ng4砂层组油藏条件,开展了聚合物驱后以石油磺酸盐为主剂的表面活性剂驱油提高采收率的室内实验研究工作。通过大量的室内实验,研制出以石油磺酸盐为主剂的复配体系,并开展了驱油效率实验。对比了几种低界面张力活性剂驱油体系的驱油效果,筛选出效果最好的石油磺酸盐驱油配方体系:0.3%SLPS-01C+0.1%助剂1#。研究了不同转注时机对石油磺酸盐体系提高采收率效果的影响,在注聚合物后含水率最低时,由于聚合物驱的作用,形成“油墙”,可防止表面活性剂窜流,此时转注石油磺酸盐体系效果最好,洗油效果最佳。

A laboratory study of further enhancing oil recovery （EOR） with a surfactant, mainly consisted of petroleum sulfonate, was done, after polymer flooding, for the Ng4 sandstone formation of No. 1 Block of Central Gudao Oilfield in Shengli Oilfield complex. A compounded system mainly composed of petroleum sulfonate was developed and then an oil displacement efficiency experiment was carried out. By comparing results of several oil displacing systems of surfactants with low interfacial tension, the optimum petroleum sulfonate oil-displacing system, 0. 3% SLPS-01C＋0. 1% co-agent 1# , was screened out. The influence of converting time of injection on the EOR of petroleum sulfonate system was studied as well. The best oil-sweeping and oil-displacing results can be obtained when the petroleum sulfonate system begins to be injected at the lowest water-cut after the polymer flooding, the reason is that, owing to the polymer flooding, an ＂oil bank＂ is formed, preventing the channeling of the surfactant.