Tool Suites Mature To Combat Damaging Torsion Vibrations Downhole
At a Glance
Section titled âAt a Glanceâ| Metadata | Details |
|---|---|
| Publication Date | 2025-08-01 |
| Journal | Journal of Petroleum Technology |
| Authors | Blake Wright |
Abstract
Section titled âAbstractâOil and gas operatorsâ pursuit of speed and efficiency when it comes to more-complex, long lateral wells has given rise to vibrations events that can sideline drilling operations by damaging vital downhole tools. One of the costly phenomena is called torsional vibration, which is caused by a twisting motion because of fluctuating torques. The key to smoothing out the drilling experience is to keep the bit and drillpipe above the bottomhole assembly (BHA), spinning in unison. If they start spinning at different speeds, a torsional event can occur that can take the drilling experience from the The Beach Boysâ âGood Vibrationsâ to Jerry Lee Lewisâ âA Whole Lotta Shakinâ Going Onâ faster than you can trip out of the hole. Have you ever wrung out a wet towel? Thatâs an instance of applied torsional vibration. You applied opposing twisting forces to the towelâs ends, causing it to twist and vibrate. Have you ever been sitting in your den and loud thumps start emanating from the laundry room? Itâs a good bet that it is due to an unbalanced load during your washing machineâs spin cycle. That can cause the drum and other components to experience torsional vibrations leading to the machine shaking excessively. Data on high-frequency torsional oscillations (HFTO)âa specific subset of the eventâwhen drilling oil and gas wells dates back several years, but early on it was dismissed as electronics noise, according to Danny Perez, product line manager at NOV. âThe frequencies were very high (approximately 1,000 Hz) and, for many, it didnât make sense for it to be an actual mechanical event,â he said. âIt wasnât until around 2017 when some companies started actively recording it, analyzing the data, and realizing it was to blame for a lot of fatigue and even failure of certain electronic components downhole.â At that time, Norwayâs Tomax was really the only game in town when it came to combating HFTO. Their Anti Stick-Slip Tool (AST) had been around since the early 2000s, developed to combat an increasing frequency of tool-joint problems and instances of over-torqued threads that caused power tongs to fail when drilling with polycrystalline diamond cutter (PDC) bits. Stick/slip occurs when the bit sticks then slips as it moves through a formation and leads to erratic drilling performance and unwanted torsional vibrations. While not specifically designed to address HFTO, the AST is effective for suppressing root oscillations in the lower-frequency ranges and thus has a strong effect on HFTO. According to the company, the tool is known to repeatedly have cut HFTO as much as 70% in advanced, 3D drilling operations. âUnlike dampeners or absorbers, the Tomax AST tool is a regulator designed to actively manage downhole drilling forces,â said Tomax founder Nils Reimers. âIts primary role is to prevent the self-exciting vibrations that frequently occur when drilling torque and weight on bit âcouplesâ at the bit-rock interface. This phenomenon is almost unavoidable when using a PDC bit at the bottom of a long drillstring, even in uniform rock formations.â