高分辨率电阻率的提取方法及应用

Methods and Applications of Extracting High Resolution Resistivity from Electrical Imaging Data

随着勘探程度的加深,勘探目标逐渐转向非常规油气藏,而具有薄互层特征的非常规储层电阻率受围岩影响较大,不能准确识别薄层。本文充分利用电成像资料高分辨率的优势,采用直方图分位数的方法提取了高分辨率电阻率曲线,在该过程中摒弃了分段线性刻度的传统方法,而采用了按深度逐点刻度,使得提取的电阻率曲线的分辨率与电成像的高分辨率保持一致,从而提高了薄层的分辨能力。通过改进阿尔奇公式,采用高分辨电阻率曲线计算含油饱和度,结果显示采用该方法饱和度与岩心化验饱和度具有较高的一致性,另外在厚层非均质性的砾岩储层中,高分辨率电阻率曲线可以识别物性较好的关键薄层,使得四性关系的分析更加准确。

With the deepening of the exploration degree,the exploration target gradually turns to unconventional reservoirs.However,the resistivity of unconventional reservoirs with thin interbeds is greatly affected by surrounding rocks,so the oil saturation cannot be calculated accurately.In this paper,the distribution characteristics of the electrical imaging data of this type of reservoir are analyzed by means of histogram statistics,and the high-resolution resistivity curve is extracted by using the quantile method.In this process,the traditional method of piecewise linear scale is abandoned,and point-by-point scale is adopted according to depth,which further improves the resolution of thin layer.The high resolution resistivity curve was used to calculate the oil saturation by improving the archie formula method.The results show that this method has a high consistency between saturation and core assay saturation,which solves the application problem of resistivity of thin interbedding,and has important practical significance for reservoir evaluation with the characteristics of thin interbedding and calculation of oil saturation.