As oil and gas production platforms reach the end of their productive lives, they must be prepared for shutdown in a safe and environmentally responsible way. Decommissioning is the final step in the lifecycle of an oil and gas facility.

Safe and responsible decommissioning is a priority for Chrysaor. This includes restoring the surroundings of platforms and facilities in line with relevant legislation, whilst taking our own environmental standards into account.

In the UK, Chrysaor is decommissioning its assets in the Southern North Sea (SNS) in collaboration with the regulators and associated third parties. The Viking area ceased production in 2016 and the LOGGS and CMS areas ceased production in 2018. Following the cessation of production, decommissioning started in this extensive area. The SNS is within a Special Area of Conservation (SAC) and our decommissioning methodology seeks to prudently minimise the environmental impact of our activities on this sensitive area.

Chrysaor conducts its operations in such a way as not to harm people and to minimise any impact on the environment. We carry out a range of activities to improve the way we operate, to reduce our impact on the environment and to prevent harm to our employees.

Chrysaor’s pipeline flushing campaign in the Southern North Sea (SNS) started in 2015. It was completed for all operated and third-party associated SNS infrastructure in 2019. Plugging and abandonment of wells began in the Viking area in 2014 and this work is still ongoing.

In the Viking area, at the LOGGS complex and on several normally unmanned installations in the LOGGS area, topsides cleaning and removal preparation has been completed. These platforms are now unmanned and sitting in cold suspension awaiting removal.

The decommissioning campaign focus is to prepare the platforms for removal by plugging and abandoning the wells, cleaning and disconnecting the topsides and carrying out removal preparation activities before de-manning into cold suspension. These structures will then be fully removed, the subsea infrastructure will be decommissioned, and the area will be cleared of any debris.

In the Viking area, eight platforms (Viking platforms KD, LD, GD, HD, DD, CD, ED and Victor JD) were removed from the field in 2019. The 500-metre zones associated with them will be cleared of debris. They will then be deemed fully decommissioned and safe to other users of the sea. The remaining platforms, Viking AR and the Viking Transportation System (VTS) Complex (BA, BC, BP and BD) are in cold suspension awaiting removal. Victor JM, a single subsea tie-back to Victor JD is awaiting plugging and abandonment.

In the LOGGS area, one platform (Vulcan UR) was removed from the field in 2019. Its 500-metre zone will be cleared of debris and it will then be deemed fully decommissioned and safe to other users of the sea. The LOGGS Complex (PR, PC, PP and PA) and some of the LOGGS platforms (North Valiant PD, Vampire OD, Viscount VO, Europa EZ, Ganymede ZD, North Valiant SP and Vanguard QD) are in cold suspension awaiting removal. The remaining platforms (South Valiant TD, Vulcan RD, Mimas MN, Saturn ND and Tethys TN) are in warm suspension (which means their wells still need to be abandoned, their topsides disconnected, and the structures prepared for removal). These will be maintained and monitored using telemetry until their wells are abandoned and the platforms are put into cold suspension. Callisto ZM and NW Bell ZX, two single well subsea tiebacks to Ganymede ZD have still to be plugged and abandoned.


In the Caister Murdoch System (CMS) area, the Caister CM platform is in cold suspension. The other platforms in the CMS area (Murdoch MD, MC and MA and the four normally unmanned installations Boulton BM, Munro MH, Kelvin TM and Katy KT) are in warm suspension awaiting well abandonment and topsides decommissioning. The Murdoch Complex is expected to achieve cold suspension in 2020 and the remaining platforms in warm suspension will be maintained and monitored using telemetry until their wells are abandoned and the platforms are put into cold suspension. Boulton HM and Murdoch K KM are single well tiebacks to the Murdoch Complex that are awaiting plugging and abandonment.


Relates to the Caister CM Infrastructure, 163 km east of the UK Lincolnshire coast in Block 44/23a.
Facilities include one infield satellite platform, comprising a topside and a jacket structure and two riser sections (1 gas, 1 methanol).

Phase 1 - From September 2018, Chrysaor worked to purge, flush and clean the gas process systems at the Theddlethorpe Gas Terminal (TGT). These works completed late in 2019. The four major gas and associated methanol pipelines connected to TGT were flushed, cleaned and filled with sea water.

We are now in Phase 2, which is demolition. Following approval of the required permits and consents, the site is being demolished to ground level. It is anticipated that all plant and buildings on the site will be demolished and the materials will be removed for re-use, recycling or disposal. These works started early 2020 and will run through until mid-2021.

Phase 3 is land remediation. Chrysaor will return the site to a condition fit for agricultural use as required by the relevant leases and planning permissions. The site is situated in a large area of Grade 3 agricultural land. The land will be returned to a similar condition to that of the surrounding fields.