A first for Newfoundland and Labrador’s offshore oil and gas industry
Our West White Rose Project achieves another milestone.
Traditionally, fixed drilling platforms offshore Newfoundland and Labrador have been assembled close to shore and then towed to the field for installation. For the West White Rose Project offshore Newfoundland and Labrador, our team at Cenovus took a different approach, a first in the region.
First, the 200,000-tonne concrete gravity structure (CGS), designed to support the topsides of the drilling platform, was transported from Argentia Harbour to the White Rose field and installed on the seabed.
This was accomplished by managing the different levels of ballast (i.e. weight) required at various points during the CGS tow out. Before the dock was flooded, seawater was pumped into the empty cells surrounding the centre column of the CGS, giving it sufficient weight to allow it to maintain stability during the flooding. Without that water weight (around 81,500 tonnes) the structure would have bobbed like a buoy. It did not and remained on the dock floor until it was time for the structure to leave the dock in May of 2025.
The float up was another precise operation. Surrounding the circumference of the CGS was a system known as the perimeter cell ballasting system, which had a total of 54 pumps, some to add water for weight, or ballasting, and others for de-ballasting. Using this system, the team waited for the optimal weather and tide conditions, and then removed water from the cells, causing the CGS to float. It was then slowly removed from the dock and floated to the head of Placentia Bay, where additional ballast was added to bring the structure to the 65m draft required for the offshore tow. It was then installed in the field, awaiting the arrival of the topsides.
Large anchor vessels towing the concrete gravity structure through Placentia Bay. The journey to the in-shore site took approximately 90 hours, with 50 hours spent waiting on weather. In total, the tow took 6.5 days.
The topsides structure was fabricated in Ingleside, TX and winched onto a heavy transport vessel, before departing to Bull Arm, NL on June 3, 2025. On July 14, in a sheltered cove on the east coast of the province, the largest heavy lift vessel in the world, Pioneering Spirit, picked up the structure off the deck of the transport ship and headed to the White Rose field. (Among the crew was Alex Pulchan, the recipient of the Cenovus Future Leaders Award at the Marine Institute, a program that provides students with real life experience in a variety of marine settings). The ship to ship transport was a first in the industry as most are performed quayside. Two days later, on a very foggy day, the topsides were safely mated with the CGS in the field, a first for Newfoundland and Labrador’s offshore and a major milestone in the completion of the West White Rose Project.
The CGS installed in the fields, with the SeaRose FPSO in the background. The two installations are within 3.5 km of each other.
LAST UPDATED: OCTOBER 2025
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