INTERPRETATION OF SINGLE-WELL TRACER TESTS USING FRACTIONAL-FLOW DIMENSIONS. PART 1: THEORY AND MATHEMATICAL MODELS

Abstract

Generalized equations using fractional-flow dimensions were derived to estimate the Darcy and seepage velocities obtained from the point-dilution and the single-well injection-withdrawal field tests conducted in fractured-rock aquifers. Seepage velocities can only be estimated from single-well tests if the hydraulic conductivity and the hydraulic gradient are known a priori. However, if a radial-convergent test is also performed between two boreholes, the kinematic porosity can be estimated and be used to estimate the seepage velocity from the single-well test results. To apply the generalized equations, the flow dimension and the extent of the flow region must be known. Therefore, the generalized radial flow (GRF) model of Barker (1988; a generalized radial flow model for hydraulic tests in fractured rock. Water Resour Res 24(10):1796-1804) is used to estimate the flow dimension because of its wide range of applications. A pumping test performed on the boreholes will yield an estimate of the fractional-flow dimension by applying the GRF model.