Self-Steering Rotary Steerable System Concept Proving Itself in Unconventional Markets

Abstract Well construction in unconventional markets represents a constant challenge of performance improvement and cost reduction. Rotary steerable systems (RSS) have demonstrated themselves as a cost-effective solution to deliver a well trajectory. The latest developments in technology, based on downhole automation, have enabled further performance improvements, reducing costs further by drilling faster and reducing wellbore tortuosity. This also contributes to the cost reduction of bottomhole assemblies (BHA) for operators. This paper presents the results and lessons learned of batch drilling a well pad in unconventional markets with an RSS using downhole trajectory automation modes and measurements while drilling tools provided by a third-party company with minimal information and interactions from the surface. Prior to the introduction of downhole automation for drilling the curve section, these sections were manually drilled by a directional driller sending downlinks from the surface, including steering ratio and tool face commands if azimuth correction was needed. This manual process was defined as Level 1 of downhole automation. Level 2 was achieved when tangent and horizontal sections were automated using inclination and azimuth hold algorithms. The next level was introduced by automating curve drilling however it was limited to starting points of 10° of inclination. Full curve automation was achieved by introducing automatic kick off from vertical transitioning to the curve section. An internal closed-loop controller sets target inclination and azimuth ramps based on dogleg demand and rate of penetration. The system responds as a first-order function with the addition of an automatic switch from manual tool face (MTF) to gyro tool face (GTF). This approach was successfully tested in the field and implemented for batch drilling of the well pad. Recent developments in drilling the curve section, including automatic kick off from vertical, drilling the curve section, and transitioning to tangent or horizontal sections, have allowed to eliminate downlinks of steering ratios. The tool reacts faster downhole delivering a smoother trajectory. The case study demonstrates rerunning the tool in batch drilling operations with minimal supporting information and fewer interactions from the surface using Level 3 downhole automation. Downhole automation now allows for the automatic drilling of all sections of a wellbore, from vertical to curve and horizontal sections, achieving Level 3 automation. This technology is advancing in unconventional markets as a proven, sustainable cost reduction and enhanced well construction operations.