The operating boundaries and associated watch circles of an offshore drilling campaign are traditionally assessed by technical analysis including simulations of rig, riser and conductor/casing response to determine the mechanical limits and confirm the design limits. V a r i o u s inputs such as weather conditions, mud weights, tension settings and other critical operational aspects have to be defined in the office. The obtained results are then incorporated into a paper based Well Specific Operating Guidelines (WSOG). This traditional WSOG approach may prove particularly limiting in harsh environment and ultra-deepwater operations [1]. Traditional WSOG limits can be overly conservative, predicting excessive non-productive time and, in some cases, indicating too high risks. In some occasions these aspects may prevent planned drilling operations from being sanctioned.
In 2016, Total Exploration & Production (TEP) drilled a complex well at a record water depth of 3,404 meters in challenging environmental conditions offshore Uruguay, with up to Beaufort 10 gales, 16m maxima waves and significant ocean current often above 2 knots. These extreme conditions for the drilling campaign highlighted the necessity of an enhanced Riser Management System (RMS). This paper presents the enhanced RMS, which includes among other features, the upgrade of the BOP inclinometers with high quality sensors, soil stiffness tracking, casing monitoring, wellhead integrity and fatigue monitoring, VIV detection functionality and enhanced operability monitoring. The paper further introduces the use of Dynamic Watch Circles (DWC) and Dynamic Operability Envelopes (DOE) based on real time monitored data and actual weather conditions. Finally, the paper discusses the potential benefits of implementing an electronic WSOG (eWSOG™) replacing the traditional WSOG for extreme drilling operations.
