Application of Joint Inversion for Mapping Fluid Parameters

摘要

A two-dimensional joint inversion technique, based on a least-squares criterion of the data misfit and model smoothness, has been developed using electromagnetic (EM) and seismic traveltime data to assess the feasibility of directly inverting for hydrological parameters, such as fluid electrical conductivity, porosity, and saturation. This is accomplished by relating hydrological parameters to geophysical properties with the help of the empirical Archie's law and the Wyllie time average equation. While the latter links the underground seismic wave velocity and subsurface media porosity, the former relates the bulk formation conductivity to hydrological parameters such as fluid conductivity and porosity. Direct joint inversion using various geophysical data also reduces the non-uniqueness of the problem since common parameters are involved, as is the porosity related to both seismic traveltime and magnetic field.