HR: 0800h
AN: NG11A-0171    [Abstracts]
TI: Three-dimensional controlled-source electromagnetic modeling and inversion for hydrocarbon reservoir mapping: The bathymetry problem
AU: * Commer, M
EM: MCommer@lbl.gov
AF: Lawrence Berkeley National Lab Earth Sciences Division, 1 Cyclotron Rd. MS 90-1116, Berkeley, CA 94720, United States
AU: Newman, G A
EM: GANewman@lbl.gov
AF: Lawrence Berkeley National Lab Earth Sciences Division, 1 Cyclotron Rd. MS 90-1116, Berkeley, CA 94720, United States
AB: The effects of bathymetry on controlled-source electromagnetic (CSEM) methods for geophysical exploration are investigated. Such effects cannot be neglected when aiming for reliable and accurate modeling and inversion results, owing to the high seawater conductivity, 3.3 S/m on average, and thus potentially high contrasts in the electrical properties between water and seabed. In the presented study, we make use of the possibilities of the finite-difference method to allow three-dimensional (3D) inversions with a high degree of model discretizations in order to simulate complex seafloor surfaces. At the same time, we separate the computational mesh for the forward operator from the model discretization mesh, through usage of a proper averaging scheme for the electrical conductivity, limiting the computational requirements. Reliability of the method is demonstrated through modeling and inversion studies for a marine survey scenario.
DE: 0545 Modeling (4255)
DE: 0644 Numerical methods
DE: 0999 General or miscellaneous
DE: 3006 Marine electromagnetics
SC: Nonlinear Geophysics [NG]
MN: 2007 Fall Meeting