Inclination Build Rate of a Point-The-Bit Rotary-Steerable Tool

Abstract

The combination of a rotary-steerable system (RSS) and power screws has become the main drilling tool for the efficient exploration and development of unconventional oil and gas. However, the application of point-the-bit (POB) rotary-steerable tools in directional drilling subjects spindle bearings to continuous alternating stress, which can lead to fatigue failure. In this study, numerical analysis and simulation are employed to guide the engineering application of rotary-steerable tools, particularly in the field of oil and gas exploitation. The structural composition and steering principles of rotary-steerable tools are analyzed. The influence of the structural parameters of the spindle on the deflection capacity of the tool is analyzed, and the optimal structural parameters are selected. Based on the results, the recommended distances between the various components of the tool could be obtained. Moreover, the maximum deflection capacity increases with torque when the WOB (weight-on-bit) is constant. Similarly, at constant torque, the maximum deflection capacity increases with the WOB. Overall, the WOB has a greater influence on the maximum deflection capacity than torque. To ensure the safe operation of the spindle, the WOB and torque must be within 200 kN and 20 kN·m, respectively. The findings of this study provide valuable insights into the safe application of POB rotary-steerable tools.