Calculation of cementation factor and saturation exponent by resistivity: a case study of silty clay formation, Changchun, China

Cementation factor and saturation exponent are important indexes for oil reservoirs evaluation. In order to facilitate the quantitative analysis of oil reservoirs accurately, a method of calculating cementation factor and saturation exponent by resistivity was proposed. Taking the silty clay (cohesive soil) samples in Changchun as an example, the resistivity expressions of cohesive soil was derived. Combined with the moisture content, porosity, and resistivity of the samples, the cementation factor and saturation exponent were calculated by multivariate fitting of resistivity formula of silty clay from two boreholes in Changchun. Results revealed that the dispersion of cementation factor and saturation exponent calculated by resistivity method is very small, and R 2 of the independent analysis are all above 0.95. The comprehensive analysis showed that it is accurate and simple to determine the cementation factor and saturation exponent by the derived resistivity expression and multiple regression analysis, which provides a theoretical basis for further calculation of oil reservoirs.