润湿性对计算纯地层含水饱和度的影响

为考察润湿性对估算纯地层含水饱和度的影响,基于Archie公式及其估算储层含水饱和度的不确定度来源分析,结合目前实验研究和油藏评价对润湿性与储层电性(饱和度指数n)关系的认识,使用数值计算方法评价了中性和水湿、油湿润湿条件下润湿性对估算含水饱和度的影响,发现在强烈水湿和油湿条件下润湿性会对含水饱和度估算产生较大的影响(可能远大于5个含水饱和度单位),并有随孔隙度减小,该影响进一步加剧的趋势.建议重视对油藏润湿性及其与电性关系的实验和理论考察.

Influence of Wettability on Calculations of Water Saturation in Pure Sandstone

In order to evaluate the influence of wettability on the estimation of water saturation in pure sandstone, based on Archie's equation and the analysis of the sources of uncertainty in the calculation of water saturation with the equation, the neutral, water-wet and oil-wet wettabilities were reviewed with numerical analyses in view of the laboratory observations on the influence of wettability on the electrical properties (e.g., saturation exponent n). The result showed that the heavy water-wet and oil-wet wettabilities will prominently seriously affect the estimation of water saturation(perhaps more than 5 water saturation units). And, such affection will become more serious when the porosity is very low. A suggestion was put forward to pay more attention to the experimental and theoretical study on wettability in situ and its influence on electrical properties.