Decommissioning & reuse Cessation of Production (CoP) and Post CoP activities
Decommissioning of wells, installations and pipelines is subject to a set of stringent national and international regulations. Overall, the obligations arising from these regulations aim at leaving wells permanently closed off and completely removing the installations, both in the safest way possible.
After cessation of production, the platform is brought into a hydrocarbon-free state by cleaning of the platform and flushing of the pipelines. The reservoir itself is fully isolated by suspension of the wells. The production platform is brought into a 'warm stack modus'.
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Well plug & abandonment P&A activities - an integral part of our work
The next step in the decommissioning process covers the final well plug and abandonment activities, usually done with a drilling rig. After completion of this process the platform finds itself in 'cold stack modus'. In order to create commercial and operational synergies (scope benefits, implementation of lessons learned), WINZ prefers to make use of a campaign-based approach.
Well abandonment means restoring the natural integrity of the formation that was penetrated by the wellbore and concerns the isolation of rock formations that have flow potential.
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Platform reuse or removal Dismantling and/or disposal activities
The final step is either the reuse or the removal of the platform (topside and jacket), followed by dismantling and onshore disposal.
In line with the waste hierarchy, reuse of (a part of) an installation is first looked at in the order of preferred decommissioning options. Several topsides (the top part of a production platform) of WINZ installations have been relocated and reused in the past and there may be opportunities to do so in the future. Where reuse is not an option, installations (topside and jacket) will be brought to shore for further disposal.
In case no reuse of reservoirs or facilities are foreseen, the pipeline(s) will be disconnected from the platform or well location. The pipeline ends will be rock dumped.
Decom and reuse track record Activities at the heart of our business
Wintershall Noordzee plugged and abandoned its first wells and removed its first production platform in 1988. In the years thereafter, decommissioning was executed on a case-by-case basis. In 2019 however, it was decided to execute decommissioning activities in a campaign-based manner. In 2021, the company started Phase I of the WINZ Decom Campaign with the execution of plugging and abandoning (P&A) of the P9-A and P9-B subsea wells, as part of a 24 wells P&A scope with the Swift-10 drilling rig. One year later, the execution of Phase II was approved, including the P&A of 17 wells and the removal of 8 offshore installations. This phase was subsequently succeeded by Phase III with the plugging and abandonment of another 18 wells and the removal of an additional 3 platforms. Further phases folowed, with Phase V currently ongoing.
From 1988 on, Wintershall Noordzee has P&A’d 137 wells, of which 78 since the start of the WINZ Decom Campaign in 2021.
In 2026, the well P&A scope includes 3 platform locations and 6 Mud Line Suspension (MLS) wells. MLS wells have never produced but need final P&A according to the current legislation. Since 2021, 15 MLS wells were P&A’d, 6 will be P&A'd in 2026 and another 3 are scheduled for 2027.
In total, 27 production platforms have been removed, of which 9 have been reused. Since 2021, 12 platforms have been removed. WINZ was able to remove 5 platforms in 2024 and another platform in 2025. For the upcoming years 2026 and 2027, the removal of another 7 platforms is scheduled, which finalizes the short-term decommissioning scope.
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News
January 2026
In 2025, WINZ successfully completed the plug and abandonment of 12 wells with the Swift 10 rig, and the removal of the L8-P platform in collaboration with Scaldis Salvage and Marine Contractors.
As WINZ continues to work towards completing its full decommissioning scope, P&A and platform removal activities will continue in the coming years.
WINZ would like to extend its sincere thanks to all colleagues, partners, contractors, sub-contractors, and stakeholders who contributed to these achievements over the past year.
May 2025
In accordance with the provisions of the Petroleum Act 1998, Wintershall Noordzee B.V. submitted the draft Decommissioning Programmes for the facilities and pipelines associated with the Wingate field for the consideration of the Secretary of State for Energy Security and Net Zero in November 2024. Following (public) consultation, approval of the Wingate Decommissioning Programmes was granted in May 2025.
The Wingate Field is located in blocks 44/18d, 44/19f, 44/23f and 44/24b in the Southern North Sea, approximately 180 km east of Scarborough. The Wingate field has been developed as a Normally Unmanned Installation with produced gas exported to the D15-FA-1 host facility located on Dutch territory. Gas production has ceased per 31 March 2025.
The facilities covered by the Wingate Decommissioning Programmes are:
- The Wingate platform
- All subsea pipelines within the UKCS associated with the Wingate field
April 2025
In April 2025, WINZ successfully completed the removal of platform L8-P. Good cooperation with Scaldis Salvage and Marine Contractors resulted in a safe, successful and cost-effective project. Final disposal will take place at Sagro Decom and it is expected that the full scope of decommissioning will be completed by Q3 2025.
WINZ would like to thank all colleagues, partners, contractors, sub-contractors and stakeholders involved in the project for their efforts and support!
November 2024
In accordance with the provisions of the Petroleum Act 1998, Wintershall Noordzee B.V. has submitted, for the consideration of the Secretary of State for Energy Security and Net Zero, the draft Decommissioning Programmes for the facility and pipelines associated with the Wingate Field. It is a requirement of the Act that interested parties can be consulted on such decommissioning proposals.
The Wingate Field is located in blocks 44/18d, 44/19f, 44/23f and 44/24b of the Southern North Sea, approximately 180 km east of Scarborough. The Wingate Field was developed as a Normally Unmanned Installation with produced gas exported to the host facility D15-FA-1 located in Dutch territory.
The facilities covered by the Wingate Decommissioning Programmes are:
- The Wingate platform
- All subsea pipelines within the UKCS associated with the Wingate field
October 2024
In October 2024, WINZ successfully completed the removal of platforms P12-SW, P6-A, L5-B, Ravn and D12-A. Good cooperation with Scaldis Salvage and Marine Contractors resulted in a safe, successful and cost-effective project. Final disposal will take place at Scaldis Salvage and Marine Contractors and it is expected that the full scope of decommissioning will be completed by Q3 2025.
WINZ would like to thank all colleagues, partners, contractors, sub-contractors and stakeholders involved in the project for their efforts and support!
May 2024
In May 2024 the HLV Gulliver of Scaldis Salvage and Marine Contractors set sail to the WINZ P12-SW platform to remove the topside first and bring it to Hoondert Services and Decommissioning B.V. in Vlissingen. Within 1 week the topside was prepared, lifted and brought to shore and a week later the P12-SW jacket was safely landed on the Hoondert quay. The first platform as part of the 2024 removal campaign of 5. Soon removal preparations at P6-A will start, followed by L5-B, Ravn and D12-A.
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