Patent ID: 7548817
Filing Date: 2009-06-16
Classification: E21B,G01V

Abstract:
1. A method of evaluating an earth formation, the method comprising: conveying a bottomhole assembly (BHA) into a borehole; making measurements during rotation and a lateral displacement of the BHA of a distance to a wall of the borehole; processing the measurements of the distance to the borehole wall to estimate a geometry of the borehole and a location of the BHA in the borehole including the lateral displacement; and estimating a value of a property of the earth formation using a formation evaluation (FE) sensor, the estimated geometry and the estimated location of the BHA; wherein the measurements are specified in a tool-centered polar coordinate system and wherein estimating the geometry of the borehole and the location of the BHA in the borehole further comprises performing a least squares fit in a Cartesian coordinate system.