Abstract:

It was found that in double logarithmic coordinates,the relationship of formation factor and porosity is a second order function and no longer the linear formula proposed by Archie in 1940's.The function can be simplified as two linear formulae.They represent different electrical properties which relate to the two predominant pore structures of sandstone,netted and pseudo capillary bundle like structure.It was also concluded in the paper that the electircal characteristics should be same if the pore structure of the reservoirs is not significantly different.Both the cementation factor m and the constant a are controlled by pore structure,and they are related to each other among the various sandstone with different pore structures.The verified prediction of values of m and a showed that the porosity,permeability and their distributions can be used to characterize qualitatively the pore structure and to predict the values of m and a.The modified Archie's formation factor vs porosity formula proposed in this paper is suite for reservoirs with different pore structures of reservoirs

Key words: pore, rock sample, electrical property, pore structure, formation factor

摘要：

在双对数坐标系中,由低孔隙到高孔隙整个范围,砂岩地层因素与孔隙率的关系为一个二次函数.根据岩电实验规律和实验样品孔隙结构特征,可以将这个二次函数简化为两个线性函数,这两个线性函数分别受砂岩储层两类孔隙结构特征控制.阿尔奇地层因素公式只反映具有网络状孔隙结构储层的电学性质.岩电实验参数m、a具有良好的相关性,表明它们均受孔隙结构特征影响.用孔隙率和渗透率可以定性表征储层孔隙结构特征,并可以预测岩电实验参数m和a值.本文提出的修正的阿尔奇公式适用于具有不同孔隙结构的储层.

关键词: 孔隙, 岩样, 电学性质, 孔隙结构, 地层因素