An offshore supply vessel struck a drilling rig off eastern Canada, causing a breach in one of the rig's columns.
The supply vessel Maersk Detector also was damaged in the Nov. 24, 2011, accident at the rig GSF Grand Banks in the White Rose field, approximately 218 miles off Newfoundland.
GSF Grand Banks had been preparing a water injection well for Husky Energy prior to a scheduled maintenance date in Halifax in January. GSF Grand Banks is owned by drilling contractor Transocean Ltd. and the 256-foot Maersk Detector by AP Moller-Maersk.
The rig's stability was not impaired, according to a report from the Canada-Newfoundland and Labrador Offshore Petroleum Board. There were no reports of injuries or pollution. The Husky Incident Command Centre was mobilized but stood down as the situation was considered to be stable.
Waves were 13 feet to 20 feet at the time of the accident, said Colleen McConnell, spokeswoman for Husky Energy's Atlantic Region.
McConnell said the impact created a breach about 13 to 16 feet long in one of the rig's columns. The damaged area was above the waterline and was isolated from the rest of the rig and made watertight, so there was no risk to rig integrity or stability.
The supply ship sustained damage to the rear portion, also above the waterline. The vessel returned to port in St. John's, Newfoundland.
AP Moller-Maersk spokeswoman Louise Münter told Professional Mariner that Maersk Detector was involved with routine cargo handling operations at the time of the incident. She declined to provide any further information regarding damage to the vessel and referred further questions back to Husky Energy.
McConnell said GSF Grand Banks had a planned shipyard maintenance program scheduled to begin in January. The work had been contracted to the Irving shipyard in Halifax, Nova Scotia. Husky worked with rig owner Transocean to bring this scope of work forward and accommodate the repairs. The rig was towed to Halifax for the shipyard repair and planned maintenance.
"At present, we would expect the rig to return to operations offshore Newfoundland in late February," McConnell said in mid-December.