An increasing deployment of rotary steerable system to drill through complex reservoirs demands considerable gains in operating efficiency. It is a known fact that one of the main drilling challenges faced by oil & gas industry is stuck pipe. The risk of stuck pipe is particularly elevated when using a rotary steerable system tool to drill through formations having geo-mechanical instability and alternating hard-soft interbedded layers. This elevated risk is due to the pivot stabilizers, typically used on such tools which have a limited flow by-pass area and high side loads at the contact points with formation. This study showcases how in geo-mechanically unstable formations, a stabilizer in a rotary steerable system tool can be replaced with a roller reamer technology to reduce stuck pipe events while still delivering steerability objectives.

Roller reamers are known to deliver reduced contact forces and torque. The analysis focuses on how roller reamer technology was used to prevent rotary stalling of a drill string while drilling, which inadvertently had been a root cause in most stuck events. It also describes how BHA was optimized to achieve directional objective. Further, it discusses how drilling execution and monitoring procedures were modified to ensure stuck pipe is avoided without compromising directional yield of the BHA.

Results are presented from actual wells, demonstrating an outstanding achievement of no stuck events on 4 back to back wells after multiple incidents of stuck pipe and lost in hole on previous wells. The best practices followed to ensure safe drilling are explored to highlight roles played by roller reamer replacement of pivot stabilizer in rotary steerable system tool, BHA optimization and real time drilling monitoring. Results prove that an engineered application of proper BHA design and effective drilling execution & monitoring can deliver efficient operations, even in most complex drilling environments.

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