Sensitivity Analysis of Torque and Drag in Offshore Extended Reach Drilling Wells Using a Simulation-Based Approach

Abstract

Extended reach drilling (ERD) is widely applied in offshore hydrocarbon development to access distant reservoirs while minimizing surface infrastructure. However, long inclined and horizontal sections in ERD wells increase torque and drag forces, which may lead to stuck pipe, excessive mechanical loading, and reduced drilling efficiency. This study presents a simulation-based sensitivity analysis to evaluate the combined influence of build-up rate (BUR) and bottom hole assembly (BHA) stabilizer configuration on torque and drag behaviour in an offshore ERD well. The novelty of this study lies in the integrated assessment of trajectory curvature and stabilizer configuration under multiple drilling operational conditions rather than evaluating these parameters independently. Well trajectories were generated using COMPASS, and mechanical load analysis was performed using WELLPLAN under run-in-hole, pull-out-of-hole, rotating-on-bottom, and rotating-off-bottom conditions. Three BUR values, namely 2.0°, 2.5°, and 3.0°/100 ft, and three stabilizer configurations consisting of two, four, and six stabilizers were evaluated, resulting in nine simulation scenarios. The results show that reducing BUR from 3.0°/100 ft to 2.0°/100 ft decreased pick-up drag from 82.3 kip to 77.7 kip and slack-off drag from 75.7 kip to 72.9 kip. Although additional stabilizers may increase localized contact points, the six-stabilizer configuration improved drillstring centralization and trajectory stability, resulting in the most favourable torque and drag response when combined with the lowest BUR. The optimal configuration was identified as BUR 2.0°/100 ft with six stabilizers. These findings demonstrate that integrated optimization of trajectory design and BHA configuration can reduce mechanical loading and support safer, more efficient offshore ERD operations.