Hole opening (dual diameter drilling) continues to receive industry attention, due to its numerous advantages. However this application presents numerous challenges, with direct implications on drilling efficiency and operational costs that worsen in harsh environments.

This presentation will cover new discussions on hole opening efficiency, with specific emphasis on harsh environments.   Factors and conditions, with influences on hole opening success, will be identified for discussion.  Solutions that challenge some of the currently held positions on BHA design, bit/reamer matching, rock failure mechanisms, drilling parameter responses and trends will be discussed.  Current industry positions on reamer failure causes and interpretations, which continue to dictate their development, will also be challenged and revised. 

Discussions will lead to new product concepts, BHA principles, drilling parameter relationships, and field execution practices.  Global performance results, focusing on harsh environment hole opening applications, will also be presented.