Norwegian oil and gas company Equinor announced on Thursday it will shut down production at its ageing Statfjord A platform in the North Sea, marking the end of the line for one of the oldest platforms on the Norwegian continental shelf.
The platform, which produced first oil in 1979, was originally scheduled to be shut down in 1999, but has since received a number of upgrades that served to extend its lifetime several times.
Equinor said it has awarded the contract for the engineering work, preparations, removal and disposal of the topside to Excalibur Marine Contractors, a company in the Allseas group. Kværner has been hired by Excalibur to dismantle and recycle the topside onshore at Stord – where the platform was built in the 1970s.
One of the largest platforms on the Norwegian continental shelf, the 84 meter-long, 54-meter-wide Statfjord A stands in 149 meters water depth in the center of the Statfjord field, approximately 120 miles west of Bergen.
The topside structure will be removed from the concrete legs in a single lift by Allseas' heavy lift and pipelay vessel Pioneering Spirit, which has a current lifting capacity of 48,000 metric tons, equal to the weight of the Statfjord A topside structure. The capacity of the vessel’s motion-compensated topsides lifting system (TLS) will be increased prior to the lifting operation.
“The vessel has done an excellent job installing three of the four Johan Sverdrup topside structures. Now they get to show their strength at the other end of an oil field’s life cycle,” said Peggy Krantz-Underland, Equinor’s chief procurement officer.
The impact assessment for the Statfjord A removal was issued for public consultation in the autumn of 2018, and preparations for shutdown and decommissioning have long been underway. Equinor said its next step is to submit its disposal plan to authorities.
“It will describe the proposed disposal solution and timing of the final shutdown of production for Statfjord A. We also plan to start permanent plugging of wells on Statfjord A this year using the platform’s drilling facilities,” says Thomas Bjørn Thommesen, Equinor’s project director for decommissioning projects.
After lifting the topside off the concrete gravity based substructure, Pioneering Spirit will transport the installation to a location near Kvaerner's facility on the west coast of Norway, where it will be transferred to Allseas’ special-purpose cargo barge Iron Lady for towage to the yard and skidding onto the quay at the disposal site. Kvaerner said its work scope includes preparing the quays, assisting during load-in and performing the dismantling of the topside.
Kvaerner, which delivered both the Statfjord A concrete substructure and the topside in the 1970s, said it will aim to recycle more than 98 percent of the materials for new purposes.
Karl-Petter Løken, President & CEO for Kvaerner, said, "Statfjord A has for decades created values and employment. This value creation and employment effects continue when we now start the process which will enable reuse of many thousands of tonnes of key materials for future purposes. We are excited to be involved in recycling of the largest structure to be removed from the Norwegian continental shelf so far. This new scope is a further boost to the activity at the state-of-the-art facility Kvaerner has at Stord for decommissioning of offshore installations."
Statfjord A was the initial installation at the Statfjord field, which has been Norway's most producing oil field, delivering more than 5 billion barrels of oil and gas and generating more than NOK 1.5 trillion ($171.5 billion) in revenues.
“Statfjord A has meant so much to many people,” said Hege Flatheim, vice president for Statfjord operations. “The platform has generated enormous values, many jobs and a proud history. Shutting down production and removing the installation is part of a platform’s life cycle, and we will make sure that this is done in a safe manner, while taking care of personnel and capabilities in a late life phase.”
The two other platforms on the field, Statfjord B from 1982 and Statfjord C from 1985, will remain on stream until at least 2025, Equinor said.
Partners in the Statfjord field include Equinor Energy AS (operator) 44, 34%, ExxonMobil 21,37%, Spirit Energy Resources Limited 14,53%, Spirit Energy Norway AS 19,76%.
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