Declining marginal profits demand that operating companies and drilling contractors review their practices and examine ways to optimize processes and reduce unplanned expenditures. One area that has been largely overlooked is iron roughneck make-up torque. Until recently, most iron roughnecks had no manufacturer's recommended method to field-verify their accuracy and no way to digitally record or transmit the torque applied to one or more connections. This has undoubtedly resulted in unnecessary expense from lost and damage drillpipe and other downhole tools. The economic impact of the problem is significant and warrants structured, collaborative approach for a solution.
In mid-2014, a collaborative group, including an operator, a drilling contractor and multiple vendors and original equipment manufacturers (OEMs), began the first parts of a six-sigma DMAIC (Define-Measure-Analyze-Improve-Control) cycle to improve makeup torque process capability. The effort involved the manufacture of a fit-for-purpose tool to measure applied torque and an exhaustive study of multiple makes, models, contractors, operators and operating conditions. The results of the study demonstrate that the process of making up drillpipe with iron roughnecks is uncontrolled (from a statistical perspective). It is also shown that the tools, as they currently exist, deviate significantly from customer-defined process capability.
Further study is required to address all the common and special cause variations in the process. Moreover, OEMs, contractors, and vendors must work together to implement process controls.
