Patent ID: 6591194
Filing Date: 2003-07-08
Classification: G01V

Abstract:
A method of logging of subsurface formations including a plurality of layers having a horizontal resistivity and a vertical resistivity, at least one of said plurality of layers having a horizontal resistivity different from the vertical resistivity, the method comprising:(a) conveying an electromagnetic logging tool into a borehole in the subsurface formations, said borehole substantially normal to said plurality of layers; (b) obtaining multi-component measurements indicative of said resistivities of said layers using said logging tool; (c) defining a model of said plurality of layers, said model including a horizontal resistivity and a vertical resistivity associated with each of said plurality of layers, each of said plurality of layers having a thickness, (d) determining components of an expected response of the logging tool to said model; (e) using a first component of said expected responses and a corresponding component of said measurements to give an updated model including updated horizontal resistivities; (f) using said updated model, a second component of said expected responses and a corresponding component of said measurements and obtaining therefrom a final model including updated vertical resistivities.