METHOD FOR ASYMPTOTIC DIPPING CORRECTION

摘要

Induction and other resistivity well logging tools determine formation conductivity at various depths but these measurements contain pronounced errors when the too l is proximate to an inclined underground bed boundary. A method to correct tool measurements includes calculating an expected tool response at a relative dip angle of zero degree and at a particular depth based on an earth model of the underground formation. An expected tool response at th e known dip is then calculated. Comparing the calculated zero-dip response with the calculated n on- zero-dip response yields the dip effect. A response is also modeled to exclude the non-lineari ty of the shoulder effect. Comparing the calculated linear response (obtained, e.g. by the Born approximation) with the calculated zero-dip response yields the nonlinear shoulder effect. The nonlinear shoulder effect and/or the dip effect may then be corrected for by subtracting them from the raw or pre-processed measurements.