Viaro operations in the Central North Sea consist of non-operated interests in the Nelson and Howe fields, the Blake and Ross fields, the B-Block, and operated interests in the Brae Complex. The non-operated interests were acquired from Idemitsu in 2017, while the interests in the Brae Complex were acquired from Marathon Oil in 2019.
The Nelson oil field (Viaro 7.48%) is located approximately 200 kilometers north-east of Aberdeen in a water depth of 88 meters. Developed with a fixed platform, it is operated by Shell and has been producing light oil from a high-quality reservoir at a depth of approximately 2,200 meters since 1994. Peak production of over 150,000 bpd was achieved in 1996 while output averaged approximately 7,190 bpd (gross), 538 bpd (net) plus associated gas in 2018. The smaller Howe field (Viaro 20.00%) is 14 kilometers east of Nelson and was brought onstream in 2004 as a single well subsea tie-back to that field’s facilities. Howe output averaged 2,761 bpd (gross), 552 bpd (net) plus associated gas in 2018. Oil from the Nelson platform is transported by pipeline to the Forties field, and then to shore via the Forties pipeline system.
The Blake oil field (Viaro 30.82%) is approximately 120 kilometers northeast of Aberdeen and has been onstream since 2001. Repsol Sinopec is the operator of the field, which is divided into two areas – the Blake Channel and the Blake Flank. These were developed separately, with six production wells plus two water injection wells drilled into the former and two production wells drilled into the latter. Oil production peaked at around 61,000 b/d from the Channel in 2001 and at around 13,000 b/d from the Flank in 2004. Total production from the field averaged 9,486 bpd (gross), 2,924 bpd (net) plus associated gas in 2018. The nearby Ross oil field (Viaro 30.82%) has been onstream since 1999 and produces up to 800 bpd (gross), 247 bpd (net). Both Blake and Ross are operated by Repsol-Sinopec and produce into the Bleo Holm FPSO via subsea infrastructure.
The Brae Complex lies approximately 220 kilometers north-east of Aberdeen in a water depth of approximately 110 meters. It consists of three Viaro-operated fixed platforms, three subsea tie-backs, numerous pipelines, and other subsea components. Third parties also utilise the Brae Complex infrastructure. The Brae Alpha platform was commissioned in 1983, initially producing from South Brae (Viaro 40.00%), while Central Brae (Viaro 40.00%) and West Brae (Viaro 40.00%) were tied-back subsequently. Brae Bravo was commissioned in 1988, but all wells had been abandoned by 2018 and the steel platform is scheduled for removal during 2020. The East Brae platform was brought into operation in 1993 and the Braemar field was tied-back to it in 2003. Production for South Brae, Central Brae, North Brae, East Brae (Viaro 36.83%), and Braemar (Viaro 26.00%) is from the Upper Jurassic Brae Formation. The Beinn field (Viaro 40.00%) reservoir is of Middle Jurassic Hugin and Sleipner age, while West Brae produces from the Upper Paleocene/Eocene Sele Formation and the Eocene Balder Formation. Production from the Brae Complex peaked in 1995 at over 300,000 boe/d and the area has produced more than 830 MMstb and plus over 3 Tcf. Brae Complex output averaged approximately 19,600 boe/d (gross), 7,500 boe/d (net), in 2018. Liquids from the Brae Area are exported via the Forties pipeline to Cruden Bay, and then on to Kinneil near Grangemouth. Gas is transported via the Scottish Area Gas Evacuation (SAGE) pipeline to St. Fergus.
Viaro has interests in four producing oil fields – Balmoral (Viaro 6.75%), Stirling (Viaro 16.00%), Beauly (40.00%), and Burghley (Viaro 41.10%) – on the B-Block, which is in a water depth of over 140 meters some 200 kilometers north-east of Aberdeen. Balmoral was developed using a purpose-built GVA 5000 semi-submersible floating production vessel (FPV). The first production from the field occurred in 1986 with Stirling following in 1995. Both Beauly and Burghley were developed as single-well subsea tie-backs to the Balmoral FPV and came onstream in 2001 and 2010 respectively. In 2018, production from the four B-Block fields in which Viaro has an interest was 1,654 bpd (gross), 615 bpd (net). Export is via the Forties pipeline to Cruden Bay.