Novel Approach of Autonomous Drilling Using Rotary Steerable System in Middle Eastern Oil and Gas Wells

The history of wellbore trajectory control can be traced back to the days of drilling with rotary assemblies. During that time, experienced directional drillers (DDs) used their knowledge about the response of bottomhole assemblies (BHA) in a specific area or field by means of drilling parameters and assembly configurations changes. This method required intensive field and human experience and still resulted in considerable deviations from the required trajectories. Technologies evolved with the introduction of motor and rotary steerable systems that have additional predicted directional responses, however, considerable human intervention was still required to control the trajectories. As the rotary steerable system (RSS) tools matured, entire sections of the well trajectories were automated with closed-loop trajectory control that required minimum human intervention. However, the curved sections continued to be drilled in manual modes with DDs interventions. A major operator focused on evaluating and validating a novel approach from its major directional drilling service provider using the auto-curve drilling mode to automatically drill the curved sections without human intervention and complete the missing puzzle of the autonomous well construction. The system is based on a minimum curvature method, which updates the target inclination and azimuth in a closed-loop system, similar to the one used in the hold inclination & azimuth method. Expected run rate of penetration (ROP) and planned dogleg severity (DLS) are needed while programming the tool for the RSS calculation update. Once the auto-curve mode is engaged in the RSS tool, updating the target inclination and azimuth will continue along the well to deliver the programmed DLS as per the ROP input. A detailed comparison of the measurements has been performed through three directional drilling curve sections in three wells. Combining the data of the three wells, 5,632-ft were drilled in different sections. The results were promising and showed an average of 70% reduction of human intervention. Furthermore, regarding the well positioning, the new auto-curve automation technology delivered the wells within the required profile target tolerances with minimum tortuosity. The novel autonomous curve drilling technology helped to minimize human error, enhance the accuracy of well positioning, and improve hole quality for drilling and workover operations. The system proved that this autonomous drilling technology is capable of improved well trajectory delivery with minimum intervention, faster well delivery, and reduction in operation costs.