Near-field ice management tactics - Simulation and field testing

摘要

Robust near-field ice management tactics have been developed for use in Arctic floating drilling. The tactics provide high confidence that a station-keeping drilling rig can be kept within the managed ice channel throughout periods of complex changes in ice drift direction and speed, and thus effectively mitigate the potentially high economic cost of an emergency disconnection. Kinematic simulations were used to design the systematic arched racetrack tactics which were implemented and tested during the Oden Arctic Technology Research Cruise 2015 (OATRC2015) conducted in the pack ice north of Svalbard at about 82°N latitude and 16°30′E longitude. The long duration field tests, conducted over 10 days using two icebreakers, show the virtual drilling rig was maintained within the managed ice channel in complex ice drift conditions that included multiple ice drift loops, cusps, and reversals. Moreover, the field observations, including satellite and helicopter imagery, confirm the fundamental simulation methods. The field results are extended through simulations to assess the impact of icebreaker fleet configuration and capability on outlet ice conditions (floe size and brash content) and the performance of the tactics against long-term ice drift records (over 1200 days with over 18,000 km of drift). Results demonstrate the importance of systematically executing the tactics and confirm that the geostationary drilling rig is kept within the managed ice channel.