SIMULTANEOUS DETERMINATION OF FORMATION ANGLES AND ANISOTROPIC RESISTIVITY USING MULTI-COMPONENT INDUCTION LOGGING DATA

摘要

Measurements made by a multicomponent logging tool in a borehole are inverte d to obtain horizontal and vertical resistivities and formation dip and azimut h angles of a formation traversed by the borehole. The invention is performed using a generalized Marquardt-Levenberg method. In this generalized Marquard t- Levenberg method, a data objective function is defined that is related to a difference between the model output and the measured data. The iterative procedure involves reducing a global objective function that is the sum of t he data objective function and a model objective function related to changes in the model in successive iterations. In an alternate embodiment of the invention, the formation azimuth angle is excluded from the iterative proces s by using derived relations between the multicomponent measurements.