Simultaneous hole opening with bit and reamer, based on acknowledged benefits, has become an drilling industry mainstay. Considering Bottom Hole Assembly (BHA) design and compliance requirements, bit and reamer in BHA, and issues with drilling parameters management, the operation presents severe drilling dynamics challenges. Additionally, several other factors initiate, sustain, and/or amplify dynamic dysfunctions. In their totality, these factors and conditions compromise hole opening efficiency, leading to increased cycle times and higher operational costs.
Current hole opening solutions and strategies have yielded inconsistent performances. Consequently, appropriate and effective solutions are needed to address above listed challenges. Data analysis must help identify factors and/or conditions that influence performance. These revelations must drive holistic solution approach for hole opening, that will be more effective at cycle time reduction, leading to project costs reductions. These expectations are only achievable, when appropriate implications are derived from effective interpretations of bit and reamer dulls. This paper will highlight and support these considerations with relevant field data, that focuses on hole opening efficiency factors, particularly dynamic dysfunctions. Cycle time effects and project costs considerations, as they relate to hole opening performance in challenging drilling environments will also be discussed.