Patent ID: 7263443
Filing Date: 2007-08-28
Classification: E21B,G01N,G01V

Abstract:
1. A method to determine the water saturation of a laminated formation having a first layer-type and a second layer-type, comprising: disposing one or more logging tools in a wellbore; measuring the formation vertical and horizontal resistivities and at least one of the first layer-type and second layer-type volumes to produce a set of formation measurements using the one or more logging tools; modeling the formation as having one or more isotropic first layer-type layers and one or more anisotropic second layer-type layers; determining from the formation model and the set of formation measurements the resistivity of the isotropic first layer-type and the horizontal resistivity of the anisotropic second layer-type; and determining the formation water saturation using the resistivity of the isotropic first layer-type and the horizontal resistivity of the anisotropic second layer-type.