In the North Sea, a major operator aimed to drill a 12 ¼-in section while staying within the agreed budget set by the authorization for expenditure (AFE). The section was planned for multiple drillbit and BHA runs due to several factors. These included the high circulating and drilling hours required to drill the extended section length coupled with likely shock and vibration, and stick-slip, which in turn presents the potential for downhole tool failures (DTFs). Additionally, the drill bit could wear out prematurely within abrasive intervals, reducing the ROP and increasing the likelihood of needing to pull the bit out for replacement.
The operator used the EnduroBlade 360 rolling diamond element bit, which maintained its sharpness throughout the abrasive interval and the section as a whole. As a result, the bit reached total depth in a single run while achieving an impressive average ROP throughout the entire interval. The SLB DBOS™ drillbit optimization system used compressive strength plots to pinpoint regions with notable variations in compressive strength, indicating potential areas for cutting structure damage. The modeling department of the i-DRILL™ integrated dynamic system analysis service combined modeling provided by the IDEAS™ integrated dynamic design and analysis platform with the existing DBOS system plots and predicted lithological tops. This integration led to the development of a predrill drillers’ roadmap, providing a clear starting point for operating parameters and removing any guesswork from the drilling process.
