A-Fields is a collective term used to describe the Ann, Alison, Annabel subsea tiebacks and the Audrey XW and WD Normally Unmanned Installations (NUIs). These are situated in the Southern North Sea, in a water depth of approximately 27m, 112km due east of Theddelthorpe Gas Terminal (TGT).
Production ceased in May 2016 and the subsea and platform wells were plugged and abandoned in 2019, with the removal of the remaining subsea infrastructure to follow. The topsides, jackets and seabed equipment will be transported to disposal yards in the UK, where more than 97% of the materials will be recycled.
The Bains field consists of a single subsea well, 113/3b-4, and is located in UKCS block 110/03C, approximately 27km west of Blackpool. The Bains field was discovered in 1988 and commenced production in 2002. Development is via well 110/3c-5 and an eight kilometre subsea tieback to the South Morecambe DP1 platform. The field was granted Cessation of Production (COP) consent in November 2017 after reaching 85% recovery.
The Whitehaven extension to the Rhyl gas field was confirmed by well 113/27b-9 well in 2013. Analysis demonstrated that the well was connected to the rest of the Rhyl field and was not a separate accumulation.
In 2018, Spirit Energy sanctioned the decommissioning of both the Bains subsea development and the Rhyl 113/27b-9 well.
DP3 - DP4
The South Morecambe field development comprises seven fixed jacket platforms, including the three-platform manned Central Processing Complex (CPC) and four Normally Unmanned Installations (NUIs) - DP3, DP4, DP6 and DP8. Production rates from DP3 and DP4 have declined to sub-economic levels and will be decommissioned aligned to Spirit Energy’s strategy, which seeks to lower operating costs and extend the economic life of the Morecambe Hub.
Over the next three years, the DP3 and DP4 wells will be plugged and abandoned, the installations will be prepared for full removal and then taken back to shore, with the aim of reusing or recycling more than 95% of the steel, equipment and other materials on the platforms.
The Ensign field is located in the Southern North Sea, in blocks 48/14a and 48/15a in a water depth of approximately 25m. The Ensign platform is a Not Permanently Attended Installation (NPAI) compromising of a four-legged steel jacket (sea searcher design) fixed installation. The two platform wells and single subsea well were plugged and abandoned in July 2019.
While in production, the fluids were exported via a 24km 10” pipeline connected to the Audrey A platform, then onwards to the LOGGS platform and onshore Theddelthorpe Gas Terminal. Production commenced in 2012 and ceased in 2019.
The Halley field consists of three separate accumulations, Alpha, Beta and Gamma, all located approximately five kilometres to the north-east of the Fulmar field. Halley consists of two extended reach wells drilled from the Fulmar platform and two subsea wells tied back to Fulmar.
The Halley field reached cessation of production (COP) in October 2018 with the subsea wells scheduled for abandonment in 2020 and the platform wells forming part of the Fulmar Platform P&A campaign in 2023.
The ST1 platform was installed in the Markham Area of the Southern North Sea in 1994, where it spent more than 20 years producing gas from the Markham reservoir. Production over the platform ceased in April 2016 and it was placed in warm suspension mode in September 2017.
In July 2019 the ST1 platform was removed from the Markham Area and on 15 July 2019 it was safely loaded into the Dales Voe decommissioning facility in Shetland where it is being dismantled for disposal, with a recycling target of 97%.
The Victor gas field was developed using a Normally Unmanned Installation (NUI), operated from the nearby Viking field. Prior to Cessation of Production in 2016, the volumes were processed at the Viking facility and exported to the terminal facilities at Theddlethorpe via the Viking Transportation System (VTS). Decommissioning is ongoing with the topsides removal in 2019 and subsea well plug and abandonment (P&A) expected in 2020.
Chestnut has outstripped all expectations since first oil in 2008, and demonstrates the value of focused, late-life management.
Located in block 22/2a of the UK Continental Shelf (UKCS), in 117m water depth, the development comprises three production wells and one water injection well, tied back to the Hummingbird Spirit Floating Production Storage and Offloading (FPSO) vessel, which was built in 2008.
Produced fluids are processed, with oil stored on the FPSO and exported via shuttle tanker, normally to Rotterdam. Expected field life is 2023+.