Region: North Sea
Content Types: Report
Date: Apr, 2023

Well-Safe Solutions, a contractor which offers the complete package for well decommissioning, has unveiled a D300 saturation diving system aboard the Well-Safe Guardian rig.

The addition, makes the semi-submersible the only one of its type in the North Sea with this capability.

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.

“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,” commented Phil Milton, Chief Executive Officer at Well-Safe Solutions.

“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 mobilisations and demobilisations. This results in lower operating costs, minimises the risk of weather-related disruption and boosts overall project efficiency.”

Milton explained that comparative analysis studies have demonstrated the value this solution can bring to the wider decommissioning industry as it streamlines processes and costs alike.

“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,” continued Milton. “We are delighted to be able to bring this solution to market as part of our vision to become the industry’s well decommissioning partner of choice.”

The manufacture, transport and fitment of the dive spread was carried out at Burntisland, Rosyth and Methil ports on the east coast of Scotland.

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.

Following further systems integration and testing, the Well-Safe Guardian will mobilise early summer 2023, returning to the Buchan field operated by Repsol Sinopec Resources UK to plug and abandon nine wells using the saturation dive system, the Trident well intervention system and the blow out preventer, realising the full potential of this single asset solution. UK-based RockSalt Subsea will support Well-Safe Solutions with diving services and personnel during all saturated diving operations from the Well-Safe Guardian.

David Whitehouse, Chief Executive Officer of Offshore Energies UK, added, “The UK offshore energy industry has a long history of developing world-class solutions to the challenges it has faced and continues to face.

“This latest development and adoption of technology on the Well-Safe Guardian from Well-Safe Solutions shows an absolute commitment to drive forward innovation to improve efficiency for the plug and abandonment of wells. These efficiency improvements will also have a positive impact on safety and environmental performance.

“After 50 years of operating in the North Sea, this level of dedication to UK innovation is important as we continue to meet the UK’s energy needs using home grown jobs, skills and technology.”