Patent ID: 6643589
Filing Date: 2003-11-04
Classification: G01V

Abstract:
A method of logging of subsurface formations including a plurality of layers each having a horizontal resistivity and a vertical resistivity, the method comprising:(a) conveying an electromagnetic logging tool into a borehole in the subsurface formations; (b) obtaining multi-component measurements indicative of said horizontal and vertical resistivities 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, an azimuth angle and a inclination angle of said layers referenced to an earth coordinate system; (d) determining expected responses of the logging tool to said model; (e) defining a data objective function related to a difference between said expected responses and said multi-component measurements; and (f) using an iterative procedure including stabilization for updating the model to reduce said data objective function.