On Application of Rock Electricity Parameters of Shaly Sand Reservoir with Low-porosity and Permeability, × Field

The experimental results of core samples saturated with solutions of 3 different salinities show that the rock electricity parameters of low porosity shaly sand reservoir are different from those of medium or higher porosity reservoir. The porosity exponent ( m ) and saturation exponent ( n ) for medium or higher porosity reservoir under different salinity solutions are similar basically. However, m and n for low porosity reservoir increase with solution salinity, respectively. Based on core test data in lab, the empirical relationships between m , n and porosity and solution resistivity ( R w) are established respectively, and thus improving Archie model for water saturation calculation. The actual application of these models to some gas reservoirs with low porosity and permeability has proved their reliability and satisfaction in logging interpretation. It indicates that core experiments of petrophysical parameters for low porosity and permeability reservoir are important in establishing logging interpretation models and formation evaluation.