Borehole Propagation With Undergaged Stabilizers: Theory and Validation

This paper discusses borehole propagation modeling in the drilling industry. A three-dimensional (3D) borehole propagation model is proposed that tracks the wellbore/stabilizer contacts caused by an overgaged borehole. The resulting model represents a nonlinear delayed system that can be efficiently used to simulate borehole propagation. Simulations are provided to show the model capabilities to capture various drilling scenarios. The predictions are also validated with actual field-test data from mud-motor and rotary-steerable operations. The proposed model can be used to (a) design mud motors and rotary steerable systems (RSSs) and evaluate their steering performance, (b) design and test surface and downhole controllers for wellplan tracking, and (c) provide predictive recommendations to help directional driller operators make steering decisions while drilling.