Sand-resistivity/conductivity and saturation evaluation in laminated formations with biaxial anisotropy

Abstract

Disclosed herein are embodiments of systems, methods, and computer program products for evaluating sand-resistivity and/or sand-conductivity, as well as saturation in laminated shale-sand formations with biaxial anisotropy (BA) in resistivity. In one embodiment, the method determines sand resistivity (R) of the laminated shale-sand formation directly from triaxial resistivities (R, R, and R) of the laminated shale-sand formation based on a bimodal model with BA anisotropy. In another embodiment, the method determines sand resistivity (R) directly based on a bimodal model with transverse isotropy (TI) anisotropy using the triaxial resistivities, horizontal resistivity, and vertical resistivity (R, R, R, R, and R). In another disclosed embodiment, the above methods may be used to perform quality control on a determined sand-resistivity and saturation of a laminated shale-sand formation.