ARCHIE’S PARAMETERS DETERMINATION WITH SATURATION ANALYSIS DATA

摘要

The first study on correlations between rock resistivity and lithology properties was carried out by G.E.Archie around 1942,which laid the foundation of integrated quantitative interpretation by geophysical logging data[1].Based on the study,Archie summarized the models of water-wet rocks and oil-wet rocks both with intergranular pores to two basic relations called Archie’s equation.Many efforts have been made in the study and application of Archie’s equation,especially in the determination of parameters in Archie’s equation and great progress has been made in recent years.For determination of Archie’s parameters,the basic method is first to measure the formation factors and the corresponding porosity of a sample,and to measure the resistivity index at different water saturations in laboratory.Then Archie’s parameters are determined by graphic or leastsquares methods.Chen et al.used simplex methods and Fuzzy regression analysis[2] and El-khatib presented weighted regression analysis[3].All the data used in the above methods must be characteristic values of lithology properties provided by laboratories,in other words,they depend on petrophysical parameter measurements.During the early exploration period,due to limited laboratory conditions or the nature of rock itself,petrophysical properties can not be measured directly,so the above methods can not be used.This paper presents a method to determine Archie’s parameters by using saturation analysis data combined with the corresponding value of geophysical logging response.For short,we may call it saturation regression analysis.