Technology Focus: Bits and Bottomhole Assemblies (December 2021)

Abstract

Well construction must always be executed safely at reduced operational costs, while ensuring appropriate wellbore quality and placement, per asset team requirements. Consequently, analysis of drilling efficiency, a critical performance indicator, has moved from maximizing rate of penetration (ROP) to improving cycle time. This recognition establishes the need for holistic solutions that address drilling challenges and promote efficient improvement strategies. This endeavor achieves well construction objectives, with associated reductions in cycle time and operations costs. Holistic solutions must start with project analysis and comparisons to offsets to identify application differences and similarities. These evaluations establish project risks, which ultimately have positive or negative effects on well construction. Consequently, implications from these risks (limiters and potential dysfunctions) must be addressed in the planning phase, or preparations must be made for their remediation during project execution. It is not enough to know what worked or failed. Rather, it is essential to understand why and how specific trends, events, results, or relationships come about. Effective and permanent remediations for all drilling dysfunctions must focus on identification and analysis of their initiating risks. Additionally, holistic solutions require detailed analysis of drilling systems, which include bits and reamers, bottomhole assemblies (BHAs), drive systems, hydraulics considerations, and drilling-parameter ranges and roadmaps. In addition to establishing component relevance, this effort must ensure their functional compatibility and effectiveness at addressing project risks. Drilling-parameter roadmaps must focus on well construction objectives and cycle time reduction, not ROP maximization. In this regard, cycle time is defined as the cumulative time associated with the following operations: pick up the BHA, drill out, drill ahead, trip out of hole, and run casing. Bits and BHAs have a major role in this discussion. The industry’s fast-developing capabilities with modeling and deeper under-standing of downhole tools and systems, coupled with applications based on big data analytics, are leading these efforts. The door has been kicked open. Let’s walk through. Recommended additional reading at OnePetro: www.onepetro.org. SPE 205965 - Oil and Gas Drilling Optimization Technologies Applied Successfully to Unconventional Geothermal Well Drilling by Junichi Sugiura, Sanvean Technologies, et al. SPE 205993 - Using Downhole Sampled High-Frequency Torsional Oscillation Measurements for Identifying Stringers and Minimizing Operational Invisible Lost Time by Andreas Hohl, Baker Hughes, et al. SPE 206064 - Mud Motor PDM Dynamics: An Analytical Model by Robello Samuel, Halliburton, et al.