Using real surface conductivity component to estimate hydraulic conductivity

Abstract

Estimation of hydraulic conductivity from surface resistivity measurements is one of the most difficult and challenging hydrogeophysical targets. The promising side of this relation is the analogy between electric current flow and water flow, whereas the grand ambiguity is the non dimensionality between both two quantities. Imaginary surface conductivity component is used recently to deduce the hydraulic conductivity via complex resistivity measurements (Börner et al 1992, 1996, and Slater and Lesmes, 2002). Since there are similar properties between imaginary (out‐of phase) and real (in‐phase) surface conductivity components, the latter is used in this paper to estimate an electrical equivalent parameter to the hydraulic conductivity. Two mathematical parameters were determined to express the hydraulic conductivity in two hydrogeological systems. Highly resistive sand formation saturated with fresh water is simulated by a parallel resistor model, whereas highly conductive clayey formation saturated with salt water is simulated by a parallel conductor model. The reliability of the proposed method is tested through applying on different resitivity data sets resembling the sand and clay systems. Application on the resistivity data either measured inside the well (Resistivity well logs) or on the ground surface (Vertical Electrical Sounding) resulted in a numerical value in the same magnitude of the measured hydraulic conductivity by pumping test.