The Conwy oil field in the East Irish Sea, UK has been producing since March 2016. Image courtesy of Tailwind Energy.
The Conwy field is tied back to the nearby Eni-operated Douglas complex. Image courtesy of Ian Mantel.
Eni UK agreed to acquire a 100% interest in the Conwy field from Tailwind Energy in May 2021. Image courtesy of Tailwind Energy.

The Conwy oil field located in the East Irish Sea, UK has been in production since March 2016. Tailwind Energy is the operator and holds a 100% interest in the offshore field, which is tied back to the nearby Douglas complex.

Eni UK, a subsidiary of Eni, agreed to acquire a 100% interest in the Conwy field from Tailwind in May 2021. Subject to regulatory approvals, the Conwy field acquisition is expected to be a strategic fit with Eni UK’s Liverpool Bay operation.

Tailwind Energy picked up a 100% interest to assumed operatorship of the field by acquiring EOG’s UK business in November 2018.

Location, discovery, and production

The Conwy field is located in block 110/12a, license P1476, in the East Irish Sea, approximately 33km north of Llandudno, Wales, UK. The water depth in the field area is approximately 33m.

EOG UK discovered the Conwy field in June 2009 and brought it on stream in March 2016. The field’s output in 2019 was estimated to be approximately 2.1 million barrels of oil equivalent (Mboe).

Conwy field infrastructure

The Conwy field development comprises three production wells, two water injection wells, and a Not Permanently Attended Installation (NPAI) platform. The well stream from the Conwy platform is transported through a 12km-long, 8in-diameter subsea pipeline to the Eni-operated Douglas platform for processing.

A separate water injection pipeline was laid from the Douglas complex to the Conwy field. The field also receives electricity from the Douglas facilities via an umbilical.

The NPAI platform, pipelines, and the umbilical were installed in 2012, while the drilling of three production wells was completed in 2013.

The Douglas platform had undergone modifications and a crude oil processing module was installed to handle well stream from the Conwy platform.

Recent developments in the field

The Conwy field production came to a halt in the second quarter of 2017 due to facility improvements and operational issues with the export pipeline connecting the Conwy field to the Douglas platform. The field resumed production in February 2018.

A conversion of condensate injection (CCI) project involving the conversion of a condensate injector well to the second water injector well at the field was completed in November 2019.

The £1.3m project led to a 25% increase in the field’s production capacity, while increasing the recoverable reserves estimate by approximately 1.5 million barrels.

Douglas complex

The Douglas complex, operated by Eni UK, is located in 29m-deep waters, approximately 23km off the coast of North Wales, UK. The complex comprises a wellhead tower, a processing platform, and an accommodation unit. The three platforms of the complex are connected by a bridge.

The crude oil is transported through a pipeline to an Oil Storage Installation (OSI) located approximately 17km north of the Douglas complex. The OSI a permanently moored barge having a storage capacity of approximately 860,000 barrels of oil. Shuttle tankers further transport the oil from the OSI to the shore.

Contractors involved

HSM Offshore was awarded the engineering, procurement, construction, installation (EPCI), and hook-up contract for the Conwy wellhead platform and reception module by EOG Resources UK in December 2010.

Technip bagged a subsea installation contract worth more than £17.2m ($27.8m) for the development of the Conwy field in March 2011.

The scope of the contract included the welding and installation of an 11.4km-long, 8in-diameter production pipeline, a water injection pipeline, and an umbilical.