North Sea-focused well plugging and abandonment service provider Well-Safe Solutions has unveiled a D300 saturation diving system aboard its Well-Safe Guardian P&A rig.
The custom-built dive spread, with capacity for up to 15 persons, enables safe access to legacy subsea wellhead and Christmas tree systems from the 1970s onwards, which were originally designed for diver intervention, Well-Safe Solutions said.
Phil Milton, Chief Executive Officer at Well-Safe Solutions, said: “With 48% of overall decommissioning expenditure in 2022 focused on well abandonment alone, Well-Safe Solutions has identified a clear market in mature basins such as the UK Continental Shelf for this technology.
“The dive spread system installed on the Well-Safe Guardian is a cost-effective, flexible alternative to the industry standard, which typically sees a light well intervention vessel (LWIV) used to plug and lubricate the well before completing decommissioning operations with a standard semi-submersible mobile offshore drilling unit (MODU).
“Our ‘single asset solution’ offers an alternative to the conventional approach and does not require multiple vessel mobilizations and demobilizations. This results in lower operating costs, minimizes the risk of weather-related disruption, and boosts overall project efficiency.
“Recent engineering and comparative analysis studies have demonstrated the value this solution can bring to the wider decommissioning industry as it seeks to streamline processes and costs alike as part of the transition to net zero carbon emissions.
“Our data shows that the use of the Well-Safe Guardian to plug and abandon (P&A) five wells over three fields in the North Sea generates a 15% total cost reduction and is 44 days quicker than using a LWIV and MODU pairing.”
Equipped with an electric bell-handling system and two hyperbaric lifeboats, the system is designed to enable diving operations to be carried out in support of well decommissioning.
Typical operations supported include cleaning, deconstruction, barrier testing, manual tree cap removal, reconfiguration of hydraulic controls and flowline removal.
Robin Kimber, Rig Manager of the Well-Safe Guardian, added: "The dive spread system is designed to work in tandem with the Trendsetter Trident well intervention system previously announced by Well-Safe Solutions in 2022.
“The potential for simultaneous operations with both technologies onboard will unlock even higher levels of operational efficiency, further minimising our environmental footprint and reducing operational risk on behalf of our clients.
Following further systems integration and testing, the Well-Safe Guardian will mobilize in early summer 2023, returning to Repsol Sinopec Resources UK's Buchan field to plug and abandon nine wells using the saturation dive system, the Trident well intervention system, and the blow out preventer.
UK-based RockSalt Subsea will support Well-Safe Solutions with diving services and personnel during all saturated diving operations from the Well-Safe Guardian.