Archie公式润湿性修正及在高阻高含水储层测井解释中的应用

A wettability modification in Archie equation and its application in well logging interpretation for the reservoir with high resistivity and water cut

渤海X油田生产层位为新近系的明化镇组和馆陶组,生产中发现部分产油层电阻率为6～8Ω·m、部分产水层电阻率为10～20Ω·m,这与油田开发中确定的测井下限和油水系统认识不符。该油田高阻高含水储层特征分析表明润湿性影响着测井解释成果,通过统计回归得到了润湿指数I_w与饱和度指数n的关系,进而对Archie公式进行了润湿性修正。实例应用表明,利用修正后的Archie公式可以准确识别储层的含油性,对于渤海海域油田后续调整和储量复算具有指导意义。

Neogene Minghuazhen and Guantao Formation are the producing intervals in X oilfield, Bohai sea, in which oil zones with 6-8 Ω·m resistivity and water zones with 10-2 0 Ω·m resistivity were found during production, not coinciding with the logging thresholds and knowledge of oil-water system identi- fied during development of the oilfield. An analysis of the reservoirs with high resistivity and water cut in the oilfield has indicated that the parameter wettability may have influences on well logging interpreta- tion. Thus a relationship between the wettability index I_w and the saturation exponent n was obtained through a statistical regression, and a wettability modification was made in Archie equation. According to the actual application, the modified Archie equation can accurately recognize the oil potential of reser- voirs, providing a guiding principle for the subsequent adjustment and reserves recalculation in Bohai sea oilfields.