多轮次吞吐热采用表面活性剂配方的实验室评价OA北大核心CSTPCD

In view of low steam displacement efficiency and decreased oil-steam ratio in heavy oil reservoirs with multiple rounds of huff and puff in Shengli Oilfield,the ratio of sodium octadecylbenzenesulfonate(SOBS)and sodium lignosulfonate(SLS)in the surfactant was screened and optimized.The performance of emulsification,viscosity reduction,interfacial activity,wettability,crude oil stripping,and oil displacement efficiency of the optimized surfactant was investigated.The adsorption capacity of crude oil on the surface of rock cores was analyzed using quartz microbalance.The experimental results show that for heavy oil in Shengli Oilfield,the optimized SOBS+SLS(mass ratio 7∶3)dosage of 0.2%(w)can reduce oil-water interfacial tension to 0.12 mN/m and viscosity to 35 mPa·s,with an interfacial tension equilibrium time for 20 min.The hydrophilicity of the rock core has also significantly improved,changing from neutral wetting to strong hydrophilic wetting.The decrease in oil-water interfacial tension increases the desorption rate of crude oil,which helps to remove oil from the reservoir and improve oil displacement efficiency.Under optimized conditions,the single-tube-physical-module oil displacement efficiency increases by 13.22 percent point.