Riser Management Systems
AS Mosley has developed two software packages which are used to control riser operations performed from a drill ship and a lightweight intervention vessel. The resulting systems are non-intrusive and require no instrumentation attached to the riser. The packages rely on measured parameters (seastate, current, vessel motion and vessel position) to determine applicable operating limits which are applied based on the actual conditions and with specific reference to a database of pre run analysis. Each of the applications also relate to the operating envelope to forecast weather in order to establish forthcoming operability.
Real Time Operating Limits (RTOL)
RTOL was developed for top tensioned risers based on operations from a drill ship. RTOL is used to generate operating envelopes for the actual environmental conditions experienced. The software is web based and accesses the measured environmental parameters (i.e. sea states, current and forecast sea conditions) through file transfer. RTOL also incorporates a fatigue logging module.
Riser Operations Control System (ROCS)
ROCS was developed for top tensioned risers based on operations from a lightweight monohull intervention vessel. ROCS is used to determine limits for vessel operations during coiled tubing riser intervention based on actual operating conditions. The software is fully integrated with the vessel network and accesses measured environmental and vessel motion parameters (i.e. sea states, current, roll, pitch, heave, position relative to well centre and vessel heading). ROCS also communicates with the subsea control system and reads the operating mode and status. In addition to this ROCS accesses forecast weather data via a file transfer. Further to providing operating envelopes, ROCS performs utilisation checks of all operating limits in relation to the Well Specific Operating Guidelines.