3D self-consistent modeling of streaming potential responses: Theory and feasibility of applications in earth sciences.

摘要

A thermodynamic description of electrokinetic phenomena leads to numerically discretizable equations to self-consistently model streaming potential responses of steady-state and time-varying hydraulic fluid flow processes. Rock parameters are evaluated self-consistently from intrinsic rock properties. Numerical values are in agreement with experimental data.;Electrokinetic current sources are associated with sources and sinks of fluid flow and with fluid flow across interfaces of changing rock and fluid properties. Leakage from a confining formation also causes electrokinetic current sources, even though fluid flow in the reservoir occurs parallel to the interface. The power density of electrokinetic current sources is on the order of ;The feasibility of streaming potential measurements is studied for applications in geosciences to estimate the magnitude of streaming potential responses: (1) Inversion of streaming potential data of seepage through a dam determined voltage cross-coupling coefficients for sand and gravel on the order of 7 x 10