Technology Focus: Bits and Bottomhole Assemblies (December 2022)
Authors: Mensa-Wilmot Graham 
Published: January 2023

Drilling-efficiency improvements must guarantee consistent reductions in project cost. The industry continues to pursue this critical requirement through different approaches—rate of penetration (ROP) maximization or cycle-time improvement. Recent advancements in technology, drilling processes, and applications characterization have begun to crystallize the differences and implications of the two methods. Most importantly, these efforts also identify crucial requirements and considerations that must be resolved as the move toward drilling analytics and automation gathers momentum.
Considerations and factors that influence project costs must be identified and analyzed from an operational perspective, instead of the usual mechanical evaluations that focus just on ROP. Recent advancements in technology development, field performance trends, and applications characterizations have established the effects and contributions of numerous other factors such as vibrations control, durability, borehole quality, directional challenges, downhole tool life, footage drilled, borehole verticality, and ROP on operational costs. The different factors have peculiar relationships with, and effects on, project costs and must not be analyzed in isolation. Consequently, solutions needed to address risks, failures, opportunities, and associated implications of these factors must be developed holistically. Actionable lookbacks and relational benchmarking that focuses on the “why” and “how” of events rather than the “what” are critical requirements of this process. This systematic and holistic approach promotes cycle-time improvement, with measurable positive effects on operational costs. The methodology ensures that problems are addressed at their source, while certifying relevance and functional compatibility of all drilling-system components.
Drilling analytics and automation must improve performance, with clear objectives to further drive down operational costs. To achieve these goals, critical pillars that focus on the holistic-solution approach and fast learning principles must be built. This strategy will promote process efficiency, explainable results, performance consistency, and fast adaptability by project teams.
The industry’s commitment to improve drilling efficiency and reduce operational costs is in full gear, yielding positive results, because of the new alignment and focus on cycle-time improvement. Holistic methodologies and solutions needed for this endeavor pose several questions that must be answered because clearer and complete pictures must be drawn for all challenges.
Recommended additional reading at OnePetro: www.onepetro.org.
SPE 204129 When Slick Is Not Smooth: Bottomhole Assembly Selection and Its Effect on Wellbore Quality by Marc Willerth, Helmerich and Payne, et al.
SPE 207423 Novel Motor Adjusts Bend Setting Downhole, Addressing Today’s Directional Drilling Challenges by Rohan D’Souza, NOV, et al.
SPE 208541 Optimizing Bottomhole Assembly Design Criteria To Improve Mechanical Performance in Slimhole Drilling Environment by Stephen Fleming, Halliburton, et al.