不同注水开发阶段水淹层混合地层水电阻率计算方法

水淹层混合地层水电阻率是水淹层剩余油饱和度评价必须确定的参数.在开发中后期,注入水会与原始地层水发生离子交换作用,因此不能简单地利用并联导电模型计算混合地层水电阻率,从而增加了计算的困难.首先根据注入水和原始地层水未进行离子交换和离子交换完全两种情况确定出不同的混合地层水电阻率计算方法;再考虑实际注水过程,确定动态的混合地层水电阻率计算模型,在动态模型中利用离子交换率表示不同阶段混合地层水电阻率的变化规律,并提出利用岩电实验和阿尔奇公式确定离子交换率的方法;最后给出混合地层水电阻率在饱和度计算时的应用方法,为定量测井解释的大批量数据处理提供编程思路.

CALCULATION OF MIXED FORMATION WATER RESISTIVITY IN WATER FLOODED LAYER AT DIFFERENT WATERFLOOD STAGES

The mixed formation water resistivity in water flooded layer is a required parameter in the evaluation of residual oil saturation. Due to the ion exchange between injected water and original formation water in the middle-late stages of development, parallel conductance model can not be used to calculate the mixed formation water resistivity. A more appropriate method is needed. Firstly, the calculation method of resistivity for different mixed formation water is determined, in terms of the two different conditions of non-ion exchange and complete ion exchange. Then considering the actual injection process, the calculation model of dynamic mixed formation water resistivity is confirmed, which use ion exchange rate, calculated by the rock-electric experiment data and Archie Formula, to show the change rule of mixed formation water resistivity at different stages. Finally, the saturation calculation method of mixed formation water resistivity is presented to provide programming ideas for quantitative logging-interpreted mass data processing.