A study on control factors to the resistivity of fractured reservoir using numerical simulation

Zhang Zhao-hui¹ and Gao Chu-qiao²

Abstract

Because many factors affecting the resistivity of fractured reservoir and complex conductive mechanism. Based on the dual laterolog principle, simulated the resistivity of water saturated fractured rock and oil saturated fractured rock on the basis of suitable physical model, the factors are analyzed which affect the resistivity of reservoir. The factors include the resistivity of formation water, and the resistivity of matrix, and fracture dip, and fracture width, and the porosity of matrix, and M value, and so on. At last, the affecting degree to resistivity of reservoir is discussed. The simulated results showed that: 1. With increasing the resistivity of matrix, the resistivity of reservoir is gradually increases, and the increasing degree of oil saturated fractured rock is bigger then water saturated. The affecting degree of fluid properties for the resistivity of reservoir increase gradually with the increase of the resistivity of matrix. 2. Fixed the resistivity of matrix, with increasing the resistivity of formation water and fracture dip, the resistivity of reservoir is gradually increases, but for the fracture width, the condition is oppositely, and the affecting degree of water saturated fractured rock is bigger then oil saturated fractured rock, and the affecting degree of fluid properties for the resistivity of reservoir increase gradually with reducing the resistivity of formation water and fracture dip and increasing fracture width. 3. The resistivity of matrix determined by archie formula, with increasing the porosity of matrix, the resistivity of reservoir is gradually reduced, but for the M value, the condition is oppositely, and the affecting degree of oil saturated fractured rock is bigger then water saturated fractured rock, and the affecting degree of fluid properties for the resistivity of reservoir increase gradually with reducing the porosity of matrix and increasing M value. 4. The affecting degree of M value and the resistivity of matrix for the resistivity of reservoir is largest, following factors include fracture dip and fracture width, the influence of the resistivity of formation water is smallest.

AAPG Search and Discovery Article #90188 ©GEO-2014, 11th Middle East Geosciences Conference and Exhibition, 10-12 March 2014, Manama, Bahrain