蒸汽驱对储层润湿性的影响

储层润湿性决定着注入流体在储层中渗流的难易程度,对原油的驱油效率、采出程度起着决定性作用。为了明确蒸汽驱过程中储层润湿性的变化,通过室内实验非稳态法水驱油、蒸汽驱油测定油藏相对渗透率曲线的变化,研究了疏松砂岩油藏蒸汽驱对储层润湿性改变的影响。实验结果表明,由水驱到蒸汽驱,油相相对渗透率增加,残余油饱和度下降,残余油饱和度对应的水相相对渗透率增加,等渗点右移;综合相对渗透率曲线特征表明,蒸汽驱使得储层润湿性向亲水方向发展。通过非稳态法研究相对渗透率曲线,由相对渗透率曲线特征点的变化来判断储层润湿性的改变简单易行,蒸汽驱对储层润湿性的改善非常有利。

Study of steam flooding on reservoir wettability

Wettability of the reservoir determines the degree of difficulty with the fluid flow in the reservoir,which plays a decisive role in oil displacement efficiency.In order to clarify the process of steam flooding reservoir and the change of wettability,we use non-steady-state method in lab by water flooding and steam flooding oil reservoir relative permeability curves measured to study changes in steam flooding caused by changes of wettability.Experimental results show that from water flooding to steam flooding, the oil relative permeability increased,residual oil saturation corresponds to the penetration of the water phase increased,the residual oil saturation decreased,and the permeability equivalent points moved right.The overall relative permeability curves show that the wettability is driven by steam reservoir to hydrophilic direction.Based on the non - steady - state relative permeability curves and relative permeability curves from the point of wettability changing of the reservoir,we can determine the changes simply and easily,and the steam flooding of the reservoir is very beneficial to the amelioration of wettability.