Rolling Depth-Of-Cut Control Improves Tool-Face Control and Overall ROPDuring Steerable Motor Applications

摘要

Rolling depth-of-cut control (RDOCC) on fixed cutter drill bits can improve rate of penetration (ROP) andreduce vibrations during steerable motor applications by reducing torque fluctuations caused by slidingfriction. Torque fluctuations are reduced by absorbing weight-on-bit (WOB) variations using a rollingbearing element, without generating additional torque that leads to tool-face control issues. Laboratory testing validated RDOCC efficiency compared to traditional depth-of-cut control limiters(DOCLs) by evaluating frictional force, load, and material resistance to axial and lateral forces. At the fieldlevel, potential applications, where tool-face control was identified as a drilling performance limiter, wereanalyzed and selected for the initial field tests. Baseline performance and target depth of cut (DOC) weredetermined using foot-based data. Additional drilling parameters, such as WOB, torque, and vibration, wereanalyzed to measure the RDOCC influence on drilling performance. The vibration data were recorded usingan at-bit data collection device (ABDCD) and later compared to data from bits with traditional DOCLs.Modified bit designs that included RDOCC with rolling elements on three blades to engage at the targetDOC were run in the selected applications and results compared to historical data, performance, and dullbit condition.