With development occurring in increasingly challenging environmental conditions, including Arctic locations, the potential benefits of riser monitoring for completion/workover operations with open sea completion risers are becoming more apparent. This is particularly the case when monitoring is combined with an on-board numerical riser model that can provide real-time operational guidance to rig personnel. The use of a Riser Management System (RMS) with these capabilities presents opportunities for significant cost savings from a maximized operational window and enhanced safety and riser integrity. This paper describes an RMS that has been supplied for a completion/workover riser application in the Barents Sea. The RMS comprises riser-mounted strain gauge instrumentation connected via data acquisition hardware to a topside PC. Data is also acquired from other vessel systems, e.g. Environmental Monitoring System (EMS), Drilling Control System (DCS) and Workover Control System (WOCS). The RMS incorporates an advanced finite element (FE) numerical model of the riser system, which coupled with the measured riser response data is used to predict the operating envelope for the vessel under the prevailing metocean conditions in pseudo-real time. This capability represents a key feature of the RMS and is used to provide operational guidance to rig personnel. The RMS also includes a riser joint tracking feature that automatically records the measured fatigue damage for the instrumented riser joints and the fatigue damage predicted by the riser numerical model for the non-instrumented riser joints. The paper describes the key features of the RMS, with particular emphasis on the procedure used to determine the riser response from a limited number of riser strain measurements using the FE numerical model of the riser. Experience with deployment of the system and its use in practice is described and some of the key benefits are highlighted.
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