含气活油高凝油相渗曲线测定及特征

目前,油水相渗曲线测量实验中普遍采用脱气原油作为实验用油,无法模拟实际储层中原油含气,设计实验使用含气高凝油,通过在恒温箱中利用高压活油瓶进行转样来保持原油高温高压条件和原始含气量,利用非稳态法测量得到含气活油高凝油相对渗透率曲线,并对曲线的特征规律及其影响因素进行研究。结果表明:含气活油相渗曲线与脱气原油相比,油相相对渗透率较高,水相相对渗透率较低,残余油饱和度降低,水驱油效率增加,含水上升变慢;随着实验温度降低,油相相对渗透率降低,水相相对渗透率提高,残余油饱和度显著升高,含水上升快,驱油效率降低;储层渗透率在高温条件下对相渗曲线特征影响较小,但在析蜡温度以下时,低渗储层的残余油饱和度与束缚水饱和度都要明显高于高渗储层,水驱油效果较差,该研究实现了对高凝油油藏相渗曲线的精准刻画。

Measurement and characteristics of relative permeability curves for high pour-point live oil

Dead oil,which can not simulate the live oil in the actual reservoir,is widely used as experimental oil in the current experiment of oil-water relative permeability measurement.The oil-water relative permeability experiment was carried out with live oil,and the high-pressure live oil bottle was used to transfer the live oil to the intermediate container,which can maintain the high temperature and pressure conditions of crude oil,as well as the original gas content.The relative permeability curves of the high pour-point live oil were obtained by the unsteady method,and then the characteristics of the curves and the influencing factors were studied.The results show that the oil relative permeability of live oil is higher than that of dead oil,while the relative permeability of water phase is lower;the saturation of residual oil decreases and the efficiency of water displacement increases;with the decrease of experimental temperature,the relative permeability of oil phase decreases and the relative permeability of water phase increases;the residual oil saturation and the water content increases rapidly,while the water displacement efficiency decreases;the permeability of reservoirs has little effect on the relative permeability curves under high temperature conditions,however,the residual oil saturation and irreducible water saturation in the low permeability reservoir are obviously higher than those in the high permeability reservoir when the temperature is below the wax precipitation temperature,and the efficiency of water displacement becomes worse.This study has realized the accurate characterization of the relative permeability curve for the high pour-point oil reservoir.