Bits and Bottomhole Assemblies

Drilling vibration continues to preoccupy the industry’s attention, primarily because of its known detrimental effects on operational efficiency, downhole tool reliability, cycle time, and project cost. In addition to drill bits and bottomhole assemblies that have been known to initiate vibrations, researchers have identified several other conditions and factors with similar contributions to vibration initiation. Vibration challenges, if effectively addressed, will have strong positive effects on drilling performance.

The debate on whether the industry is doing enough to address vibrations continues to linger. This discussion must be put to rest because the fact is that researchers are passionately obsessed with this challenge. Presently, the focus has shifted from mere awareness to efforts that seek to establish a deeper understanding of this subject. In addition to identifying and characterizing different vibration modes, the current emphasis also delves into their sources. Knowledge gained from these efforts, particularly awareness of the different factors contributing to vibration, is driving development of holistic solutions to the challenge.

Numerous initiatives, including downhole tool development for data acquisition, big data and analytics, innovative modeling techniques, and calibration and optimization of modeling results, have been deployed in this effort. Positive results with measurable effects in field operations have been achieved. In all cases, development of effective solutions must start with appropriate characterization and identification of the specific modes of vibration. Its sources must also be established so that developed solutions can be tailored for maximum effectiveness.

The holistic approach has identified borehole spiraling, especially in long lateral sections, as a primary source of vibrations and other drilling challenges. Solutions to address this challenge are currently in development. Yes, we continue to seek effective solutions to address the problem. However, we always encounter new challenges as we drill deeper into harsher environments, increase dogleg-severity requirements, and extend our departures while also drilling highly heterogeneous formations. We cannot stand still; we must keep moving ahead.

This Month's Technical Papers

Isolator Tool for High-Frequency Torsional Oscillation Proves Effective

BHA Behavior-Prediction Model Offers Potential for Automated Analysis

Resolving Torsional Vibration in Limestone Reservoirs Reduces Equipment Damage

Recommended Additional Reading

SPE 196020 Case Studies: Optimizing BHA Performance by Leveraging Data and Advanced Modeling by Mojtaba Shahri, Apache, et al.

SPE 194120 Mitigation of Multifrequency Stick/Slip by Zhijie Sun, Halliburton, et al.

SPE 194150 Industry’s First PDC Bit Gauge Design for Improved Tracking In North American Horizontal Wells by Reed Spencer, Baker Hughes, a GE Company, et al.

Graham Mensa-Wilmot, SPE, is a senior adviser for drilling engineering at Chevron Energy Technology Company. He is the MAXDRILL (performance drilling) project leader and has more than 30 years of experience in drilling-applications research, downhole-tool development, drilling mechanics, drilling-­vibration identification and remediation, and performance-­drilling improvement. He holds an MS degree in drilling engineering from Romania’s Petroleum-Gas University of Ploiesti. Mensa-Wilmot has authored several technical papers and holds several patents. He serves on the SPE/IADC Drilling Conference Program Committee and the SPE Drilling and Completions Committee. Mensa-Wilmot served as an SPE Distinguished Lecturer in 2016–2017 and previously served as a drilling-dynamics and performance-drilling instructor for the Petroleum Network Educational Courses series. He serves on the technical board of the SPE Gulf Coast Section and is a member of the JPT Editorial Committee. Mensa-Wilmot can be reached at

Bits and Bottomhole Assemblies

Graham Mensa-Wilmot, Senior Adviser for Drilling Engineering, Chevron

01 December 2019

Volume: 71 | Issue: 12

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