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 tool 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 the known dip is then calculated. Comparing the calculated zero-dip response with the calculated non-zero-dip response yields the dip effect. A response is also modeled to exclude the non-linearity 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.