含水饱和度指数n值计算方法探讨

Discussion on Calculation Methods of Water Saturation Index n

研究了不同样品在不同实验条件下的含水饱和度指数n值的计算方法。根据岩电实验中含水饱和度Sw与电阻增大率I交会曲线的特征,分析了样品孔隙结构及含水饱和度对含水饱和度指数n值的影响,使用了I-Sw分段回归法、n-Sw相关分析法以更精确地计算样品的含水饱和度指数n值。实验分析了不同的油藏参数与含水饱和度指数n值的关系,认为储层性质和流体性质是影响含水饱和度指数n值的关键参数,对实际油藏应通过多因素拟合的方法求解含水饱和度指数n值。

Studied are calculation methods of water saturation index n under different experimental conditions for different samples. Based on characters of crossplot of water saturation Sw and resistivity increscent index I, the influences of pore structure and water saturation on n have been analyzed, and calculation methods, including sectional regression method, correlative analysis method of water saturation Sw and n, are used for calculating the n more accurately. The relationships between different reservoir parameters and n are analyzed experimentally, it shows that the reservoir character and fluid property are key factors of n, and for real reservoir multi-factor regression should be utilized to calculate the n.