低阻油层原始含油饱和度的计算方法及研究意义

低阻油层原始含油饱和度在识别油水层时起着关键性作用,以往计算时都是利用电性资料获取,用 阿尔奇公式求取的结果误判了许多油层,基于此考虑,本文提出了在利用岩心分析资料的基础上,结合毛 管压力曲线回归分析计算含油饱和度的方法,该方法把毛管压力、岩心孔隙度、含油高度等参数联系了起 来,通过统计分析建立了VHg-Φ回归方程,应用该方法能比较真实地计算出低阻油层的原始含油饱和 度,现场应用表明这种方法是可信的。

Calculation procedures of initial oil saturation of low resistivity oil layers and their significances

Initial oil saturation of low resistivity oil layer play a critical role in identification of oil/water layers. It was commonly calculated by using electric properties data, but many oil layers have been bypassed when the calculation results of Archie's formulas were used as discrimination standards. This paper presents a method which calculates oil saturation by using core analytical data and in combination with analysis and calculation of nonlinear regression of capillary pressure. This method establishes relations between capillary pressure, core porosity and oil column and builds V Hg - Φ regression equation through statistical analysis. Relatively real initial oil saturations of low resistivity oil layers can be achieved. Field application shows that it is reliable.