水淹层地层水电阻率的二步确定方法

摘要

通过水淹层地层水电阻率变化规律的分析,认为水淹层地层水电阻率的变化具有分段变化特征,可以近似地分段取值.通过水淹层测井响应特征及变化规律分析,提出一种二步确定水淹层地层水电阻率的方法.确定水淹层测井电阻率的相对减小量、自然电位曲线基线偏移量和测井曲线形态特征,根据这些特征选择地层水电阻率的值.在A油田的实际应用证明该方法是有效的.%The formation water resistivity in water-flooded zone is an important parameter in the saturation calculation and reservoir evaluation. With the analysis of the formation water resistivity changes in water-flooded zone, it is proved that there are staged change characteristics of formation water resistivity in water-flooded zone, and we can choose resistivity values depending on the water-flooded stages. According to the analysis of the characteristics and changes of logging responses, a two-step determination method of the formation water resistivity in water-flooded zone has been proposed. First, the relative diminution value of water-flooded reservoir, base offset of spontaneous potential curve and well logging curve shape are determinated. Secondly, according to these characteristics, the formation water resistivity is selected. This method has been applied successfully to A oilfield.