Electromagnetic ray-trace tomography

Abstract

Abstract Electromagnetic (EM) tomography can be used to estimate the distribution of electrical rock properties between boreholes. For typical oil field well spacings and reservoir electrical characteristics, crosswell EM measurements are sensitive primarily to the electrical conductivity, not the permittivity. Ray-tracing methods normally associated with undamped propagating waves can also be applied to the rapidly attenuated, diffusive EM waves encountered in the petroleum reservoir environment. Thermal noise considerations place an upper limit of approximately 20 skin depths on the separation between wells.