Precise borehole geometry and BHA lateral motion based on real time caliper measurements

摘要

Disclosed is a method for estimating a geometry of a borehole penetrating the earth. The method includes: performing a plurality of borehole caliper measurements with N transducers at a plurality of times, wherein for each time a measurement set comprises measurements made by the N transducers at that time; dividing a cross-section of the borehole into S sectors; obtaining an estimate of the borehole geometry by connecting representative radius points in adjacent sectors; displacing each measurement set according to a displacement vector related to an offset of each measurement set from the estimated geometry if the displacement vector exceeds a selection criterion; iterating the obtaining an estimate of the borehole geometry and the displacing each measurement set based on a latest displacement vector; and providing a latest obtained estimate as the geometry of the borehole when all of the displacement vectors no longer exceed the selection criterion for the displacing.

主权项

1. A method for estimating a geometry of a borehole penetrating the earth, the method comprising:
performing a plurality of borehole caliper measurements with N transducers at a plurality of times, wherein for each time a measurement set comprises measurements made by the N transducers at that time; dividing a cross-section of the borehole into S sectors, the cross-section being in an X-Y plane that is perpendicular or sub-perpendicular to a Z-axis that is a longitudinal axis of the borehole using a processor; obtaining an estimate of the borehole geometry by connecting in adjacent sectors a representative radius point that represents a radius representative of measurements in each sector using a processor; displacing each measurement set according to a displacement vector related to an offset of each measurement set from the estimated geometry if the displacement vector exceeds a selection criterion using a processor; iterating the obtaining an estimate of the borehole geometry and the displacing each measurement set based on a latest displacement vector using a processor; and providing a latest obtained estimate as the geometry of the borehole when all of the displacement vectors no longer exceed the selection criterion for the displacing using a processor.