Station-keeping in harsh environments requires substantial planning and additional contingency considerations over less extreme environments.
Arctic drilling often has biological and other natural considerations, such as whale migration seasons and ice flow. In order to overcome these issues, drilling work is done seasonally, with watch vessels present at all times to ensure that the drilling vessel has an adequate T-time to get off of location. This leads to significant down time from "near misses" and moving the rig to / from location.
Tropical drilling requires significant planning around possible cyclonic activity, referred to as hurricanes in the GoM. There are several actions that are taken to mitigate the risks and consequences of sudden cyclones, including the use of DP vessels, stronger preset mooring systems, or stacking older rigs during hurricane season. DP vessels are not capable of the tight watch circles that drilling requires in shallower water depths without utilizing a mooring system, and stacking rigs is a costly activity.
The expenses due to lost drilling time associated with the aforementioned phenomena easily reaches hundreds of millions of dollars annually on a global scale. In order to help reduce these costs, a reliable mechanical quick release device can be used to reduce T-times, and allow MODUs to leave locations in considerably less time. The design and testing of a mechanical quick release device from concept to prototype testing, potential cost savings from the utilization of such a device, and potential uses to enhance the drilling capabilities of DP vessels will be presented in this paper.