大庆油田杏十二试验区活性水驱油体系优选研究

针对大庆油田L区块产水率高的问题,在杏十二试验区开展活性水驱油体系研究。结合区块油藏条件,选取合适的表面活性剂,通过室内物理模拟实验对活性水驱油体系进行优选。结果表明,表面活性剂能有效降低油水界面张力,提高石油采收率,且随着活性水注入质量分数的增加,注入压力增大。在室内驱油实验中,当1^# 活性水质量分数超过0.08%时,采收率增长幅度明显变缓。最终结合实验结果与经济评价方法,筛选出适合杏十二试验区的驱油体系,即甜菜碱型表面活性剂与地层水以质量分数0.08%配成活性水,最优用量为0.25PV。

Optimization of Activated Water Driving System for Xing-12 Test Block in Daqing Oilfield

In view of excessive water yield of L block in Daqing oilfield, studies of activated water driving system were conduct in Xing-12 test block. Combined with block reservoir condition, suitable surfactants were selected, and optimization of driving system for activated water was carried out by the result of laboratory physical simulation experiment. It can be found that oil/water interfacial tension effectively decreased and oil recovery was enhanced with addition of surfactant. And injection pressure also rises up with increase of concentration of surfactant. In the laboratory oil driving experiment, the growth range of recovery ratio tended to slow down when the mass fraction of 1^# activated water exceeded to 0.08%. Eventually the paper combines with experiment results and methods of economic assessment, the oil driving system suitable for Xing-12 test block is screened out. That is the mass fraction 0.08% activated water prepared with betaine type surfactant and formation water, and optimal dosage is 0.25 PV.