Improved estimation of wellbore dogleg from tool bending moment measurements

摘要

A disclosed borehole curvature logging system includes: a drill string having a bottomhole assembly (BHA) with sensors providing actual deformation and bending moment measurements as a function of BHA position at spaced-apart intervals on the BHA; a processing system that retrieves said actual measurements and responsively generates a log of borehole curvature; and a user interface that displays the borehole curvature log. The processing system implements a method that generates the log by: providing an estimated borehole trajectory; deriving predicted deformation and bending moment measurements based on the estimated borehole trajectory; determining an error between the predicted measurements and the actual measurements; updating the estimated borehole trajectory to reduce the error; repeating said deriving, determining, and updating to refine the estimated borehole trajectory; and converting the estimated borehole trajectory into a borehole curvature log.