稀油聚驱后蒸汽驱温度与压力对采收率的影响

The Effect of the Temperature and Pressure on Thin Oil Recovery by Steam Flooding after Polymer Flooding

为了探索稀油油藏聚合物驱油后蒸汽驱注入温度与压力对原油采收率的影响,采用大庆萨尔图油田天然圆柱状岩心和模拟地层油,首先在45℃环境下进行水驱和聚驱,而后在模拟环境温度和注入温度的双温度场条件下进行了蒸汽驱实验研究。结果表明:在水驱-聚驱累计采收率达54.4%的基础上,蒸汽驱采收率提高幅度为28.3%;当压力一定时,不同注汽温度的蒸汽驱采收率均随着注汽PV数的增加而增加,并趋于各自的稳定值,有效PV数约为1.4;蒸汽驱采收率提高幅度随岩心平均温度的提高呈先增后减的趋势,最佳驱替温度范围为岩心平均温度超过饱和水蒸汽温度(10～15)℃;随着压力的增加,得到相同采收率的注汽温度也相应增加,尽可能降低压力将可利用相对较低的注汽温度获得较高的采收率,并减少注汽过程的热量消耗。

In order to exploit the effect of the temperature and pressure of steam injection on thin oil recovery of the homogeneity layers,the natural rocks of Daqing Saertu and simulant oil are used.First,the water flooding and polymer flooding were studied in 45℃,and then the steam flooding in the condition of the environment temperature and injection steam temperature were studied.The experimental results showed that：the range of steam flooding recovery increased 28.3% when the water flooding-polymer flooding accumulated recovery reached 54.4%;The steam flooding recoveries of different temperatures of steam injection increased when the values of PV of the steam injection increased.The effective number of PV was about 1.4 when the pressure are fixed and tend to each stable value;The range of steam flooding recovery increased and decreased when the average temperature of core increased,and the range of the best flooding temperature was that the rock average temperature was higher（10～15）℃ than the saturated steam temperature;The temperature of injection steam of the same recovery increased when the pressure increased.The higher recovery could got by lower injection steam temperature,and the heat consumption in the process of injection steam was reduced too when the pressure was reduced as much as possible.