温度对特低渗油藏油水相对渗透率的影响

Effect of temperature on oil-water relative permeability in ultra-low permeability reservoir

针对目前有关特低渗油藏相对渗透率曲线研究较少的现状,通过岩心流动实验,得到不同温度条件下特低渗岩心的油水相对渗透率曲线,将其与中渗油藏的相渗曲线进行对比,并对其相渗曲线的特征值进行了定量描述。对比分析得出:相对中渗岩心,特低渗岩心的相渗曲线有整体向左移动的趋势,残余油饱和度较高,且该饱和度对应的水相相对渗透率很低,岩心的水驱最终采收率较低;随着温度的升高,特低渗岩心的束缚水饱和度逐渐升高,油水同流区变宽,等渗点饱和度右移,残余油饱和度相应减小,岩心的水驱最终采收率增大。

Based on the condition of limited report about relative permeability culwe of uhradow permeability reserw）ir, the oil-water relalive permeability curves of ultra-low permeability eores were achieved under differenl temperatures through physical simulalion experiment in this paper. The relative permeability curves were compared between uhra-low permeability cores and medium permeability cores. And the characteristic values of relative permeability curves were described quantitatively. Through contrast and analysis, the resuhs show that compared with the curves of medium permeability cores, lhe relative permeability et, rves of uhra-low permeability cores present the trend shifting to left and the higher residual oil salutation. The relative permeability of the water phase corresponding with the residual oil saturation is very low, so the ultimate recovery efficiency of waterflooding is lower. With the increasing of lemperature, the irreducible water saturation of uhra-low permeability cores increases gradually, the water-oil concurrent flow zone becomes wide, isopotal saturation point shifts to right and remaining oil saturation decreases correspondingly, which lead to a high uhimate recovery efficiency of waterflooding.