页岩岩芯复电阻率频散特征主要影响因素的实验研究

Experiment research of the main influence factors of shale sample complex resistivity dispersion characteristics

影响岩石复电阻率及其频散特性的主要因素有孔隙水盐度、孔隙度、饱和度、渗透率、温度以及各向异性等,对于页岩还与TOC含量密切相关。实验中对昭通地区两口井59块页岩岩芯进行了复电阻率测量,分析了岩芯饱和水盐度、各向异性以及TOC含量对岩芯复电阻率及其频散特性的影响。发现页岩复电阻率和极化率随含盐饱和度增加而减小;在垂直与平行于层界面的方向电阻率与极化率相差较大,各向异性明显;页岩复电阻率与有机碳含量有着负相关性。实验结果为建立页岩储层建模和电磁勘探方法,对页岩储层进行勘探和综合评价提供了有价值的资料。

The major influence of rock complex resistivity and the dispersion characteristics are pore water salinity,porosity,permeability,temperature,and anisotropy,etc;and for shale rocks is also closely related to the TOC content.In the experiment we measured 59 shale samples of complex resistivity and analyzed the influence of different salt saturation,anisotropy and the content of TOC on shale complex resistivity and the dispersion property of two wells.We find that the complex resistivity and chargeability of shale decreases with the increase of salt saturation;and has a large difference in the vertical and parallel to the direction of the interface layer,the anisotropy is obvious;Besides,the complex resistivity of shale has negative correlation with the TOC content.The experimental result provides valuable information for establishing the shale reservoir complex resistivity model and explorating and comprehensive evaluating the shale reservoir by electromagnetic prospecting technology.