Ithaca Energy, one of the UK’s largest independent oil and gas companies in the UKCS with stakes in six of the ten largest fields in the UK North Sea and two of largest prospective developments, is celebrating its 20-year anniversary.

Company profile

Ithaca Energy is a leading independent oil and gas operator in the North Sea.

Founded in 2004, Ithaca Energy has been on a rapid growth trajectory in the last three years, following a series of transformational M&A transactions and organic growth, building operations with significant scale and longevity. Today, Ithaca Energy is one of the largest independent oil and gas companies in the UKCS, ranking second by resources and third by production.

With stakes in six of the ten largest fields in the UK North Sea and two of largest three prospective developments, the Company play a pivotal role in meeting the current and future energy needs of the UK. 

Ithaca have built a diverse and high value portfolio of operated and non-operated assets across the Northern & Central North Sea and West of Shetland.

OPERATED ASSETS

Ithaca Energy has a solid and diversified producing asset portfolio, generating significant free cashflow, and material upside potential from an attractive pipeline of greenfield development opportunities. The Company's operated assets are located in the Northern and Central North Sea, West of Shetland and Moray Firth areas of the UK Continental Shelf.

Alba field

The Alba field lies about 130 miles (210 km) north-east of Aberdeen, Scotland, in the UK Central North Sea, in water depths of approximately 453 feet (138 m).

Discovered in 1984 in Block 16/26, Alba is a heavy oil field and was one of the first shallow Eocene reservoirs to be successfully developed in the North Sea. First oil was achieved in January 1994.

The field facilities include a fixed steel platform, the Alba Northern Platform, and a Floating Storage Unit (FSU), the first to be purpose-built for the UK sector of the North Sea. The field was further developed in 2001 through the addition of the Alba Extreme South subsea production centre.

In 2021 Alba produced a net daily average of 6,940 barrels of liquids. Since first production in 1994, it has produced over 438 million barrels of oil.

Alba is operated by Ithaca Oil and Gas Limited (36.7 percent) with Waldorf Production (25.68%), NEO Energy (17%), Spirit Energy (12.65%) and EnQuest (8%) holding non-operated working interests in the field.

Alder

Alder is a HPHT gas field tied-back to Britannia via an advanced 17-mile (28 km) subsea pipeline and a single producing well. The Alder field has been online since 2016 and is operated by Ithaca Energy (UK) Limited (73.68 percent); Harbour Energy holds a 26.32 percent non-operated working interest in the field.

Cambo field

The Cambo field is located approximately 80 miles west of the Shetland Islands, approximately 20 miles south from Rosebank, and approximately 20 miles north from Schiehallion. Discovered in 2002, the field is a large basement high with sedimentary sequences atop the structure and sits on the Corona Ridge structural feature. In November 2023, Ithaca completed its acquisition of the remaining 30% stake in Cambo from Shell U.K. taking the Company’s stake to 100%,

Cambo will be developed using a purpose-built Sevan FPSO. Modern equipment designed to operate without the need for routine flaring or venting of hydrocarbons will be used to reduce emissions. When production commences, the field is expected to produce less than half of the amount of CO2 for each barrel produced than the average UK field. The development will be built electrification-ready.

Captain field

The Captain field lies approximately 90 miles (145 km) north-east of Aberdeen, in the Outer Moray Firth, in water depths of around 346 feet (105.5 m).

Discovered in 1977 in Block 13/22a, the Captain field achieved first production in March 1997, thanks to key technology developments in horizontal drilling and down-hole pumps in well bores.

In 2020, daily production averaged 25,520 barrels of liquids and 3.0 million cubic feet of natural gas.

Ithaca Energy continues to implement projects designed to sustain production and increase recovery at Captain. This includes active platform and subsea well in-fill drilling and completion programmes targeting key areas of the reservoir. Continued development drilling is expected through the next decade.

Cook field

The Cook field lies approximately 105 miles (170 km) north-east of Aberdeen, in the UK Central North Sea, in water depths of approximately 301 feet (92 m).

Discovered in 1983, in Block 21/20a, the Cook field is an oil and gas condensate field. First oil from the field was achieved in April 2000.

The Cook field development consists of one production well (on natural depletion) tied back approximately 10 kilometres to the Anasuria Operating Company operated floating production, storage and offloading (FPSO) vessel, which also serves as a host facility for a number of nearby fields.

Cook is operated by Ithaca Energy (UK) Limited (61.345 percent) with Ping Petroleum (19.327 percent), and Hibiscus Petroleum (19.327 percent) holding non-operated interests in the field.

Erskine field

The Erskine field lies approximately 150 miles (241 km) north-east of Aberdeen, in the Central North Sea, in water depths of about 296 feet (90 m).

Discovered in 1981 in Block 23/26, Erskine is a gas condensate field. It was the first high-pressure, high-temperature field to be developed in the UK Continental Shelf. First production was achieved in November 1997.

Erskine is operated by Ithaca Energy (UK) Limited (50 percent) with Harbour Energy (32.0 percent), and Serica Energy (UK) Limited (18 percent) holding non-operated interests in the field.

Fotla Discovery

The Fotla Discovery, operated by Ithaca Energy, is located in Block 22/1b of the UK North Sea in 431 ft of water, approximately 10 km southwest of the Ithaca Energy operated Alba field. The field was discovered in August 2021 by the Group’s drilling of the 22/1b-12 well and subsequently appraised by two side-tracks. As previously stated, development plans are currently being evaluated, with first production from the Fotla Discovery targeted in 2026. The conceptual field development plan consists of a subsea tieback to existing infrastructure.

Greater Stella Area

The Ithaca Energy operated Greater Stella Area is located in the heart of the Central Graben area of the Central North Sea, on the UK Continental Shelf. It is an area surrounded by various large producing fields, predominantly operated by the Majors, and numerous undeveloped discoveries.

The Greater Stella Area licences contain the Stella and Harrier fields, both of which are in production, and the Vorlich field, which is currently in the process of being developed. The Company also owns operated interests in a number of satellite fields that are planned for development via the hub infrastructure, being the Hurricane, Austen and Courageous discoveries.

The Company's focus on the Greater Stella Area is driven by monetisation of over 60 million barrels of oil equivalent of net proven and probable reserves (as independently assessed by Sproule International Limited) and the generation of additional value via the wider opportunities provided by the range of undeveloped discoveries surrounding the production hub.

Development overview
Production commenced from the Stella field in early 2017 and from Harrier in 2018. The development involved the drilling of subsea wells tied back to the Ithaca Energy owned and operated “FPF-1” floating production facility, with the onward export of oil into the ConocoPhillips-operated “Norpipe” system and gas into the Kellas Midstream-operated “CATS” system. Development of the Vorlich Field is ongoing following formal approval of the Field Development Plan which was granted in September 2018. Vorlich is being jointly developed with BP.

Stella field
Discovered in 1979 in Block 30/6-2, the Stella field comprises the Stella Andrew sandstone reservoir containing light oil and rich gas condensate and the Stella Ekofisk reservoir containing a volatile oil.

Since the discovery well, seven subsequent appraisal reservoir penetrations were made on Stella including the final appraisal wells drilled by Ithaca in 2010.

Five development wells were drilled between 2013 and 2015 to allow production from both reservoirs to commence.

Ithaca Energy holds a 100 percent interest in the Stella field.

Harrier field
The Harrier field lies approximately 158 miles (255 km) East of Aberdeen, in the Central Graben Area of the Central North Sea in water depths of about 295 feet (90 m).

Discovered in 2003 in Block 30/6-4, the field comprises the Harrier Ekofisk and Harrier Tor chalk reservoirs, both containing gas condensate.

Ithaca Energy drilled a dual lateral fracture stimulated multilateral development well in 2018 to access both the Harrier Tor and Ekofisk reservoir intervals to enable production from the field to start up in mid-2018.

Ithaca Energy holds a 100 percent interest in the Harrier field.

Vorlich field
The Vorlich field lies approximately 88 miles (241 km) east of Aberdeen, in the Central North Sea in water depths of about 262 feet (80 m).

Discovered and appraised in 2014 in Block 30/1c and jointly developed with BP, first production from the field was in November 2020.

The Vorlich field contains hydrocarbons in a Palaeocene sandstone reservoir and production is via 2 wells tied back to the FPF-1 floating production facility, which lies at the centre of the Greater Stella Area production hub.

Ithaca holds a 34% working interest in the Vorlich field (its partner, BP holds a 66% working interest).

K2

In July 2023, Ithaca announced the results of exploration drilling at the K2 prospect, located in Block 22/14c of the Central North Sea.

Ithaca Energy, acting as the operator, discovered that hydrocarbons were present in the reservoir in the Forties member sandstones, with 45 feet of net thickness. Logs were acquired to establish reservoir quality and further analysis of the well results will be performed to determine future activity and the recoverable resources estimate. Ithaca Energy, together with its joint venture partner, have decided to perform an appraisal sidetrack following these encouraging results in the main bore.

Ithaca Energy holds a 50% working interest in the licence with the remaining 50% working interest held by Dana Petroleum.

NON-OPERATED ASSETS

Britannia and satellites

The Britannia field lies approximately 130 miles (210km) northeast of Aberdeen, Scotland, in the UK Central North Sea, in water depths of approximately 480 feet (146m). The Britannia field is operated by Harbour Energy (58.65%), with Ithaca Energy owning a 32.38% non-operated working interest in the field alongside NEO Energy 8.97%.

Brodgar

The Brodgar gas condensate field lies 89 miles (143km) north-east of Aberdeen, in the UK Central North Sea, in water depths of about 460 feet (140m). Brodgar is operated by Harbour Energy (93.75%), with Ithaca Energy owning a 6.25% non-operated working interest in the field. The field has been developed as a subsea satellite of the Britannia field in Block 21/3a. First production from Brodgar was achieved in 2008.

Broom

The Broom oil field is located in Block 2/4a and lies approximately 310 miles (500km) from Aberdeen, in the Northern North Sea area of the UK Continental Shelf, in water depths of approximately 485 feet (147m). The field is operated by EnQuest (63%), with Ithaca Energy (8%) and MOL (29%) owning a non-operated working interest.

The Broom field moved into the decommissioning phase with the cassation of production of the host Heather platform in 2020. Ithaca Energy are working with the field operator to plan and execute the safe abandonment of the facilities and wells.

Callanish

The Callanish oil field lies 98 miles (158km) north-east of Aberdeen, in the UK Central North Sea, in water depths of about 490 feet (150 metres). Callanish is operated by Harbour Energy (85.5%), with Ithaca Energy owning a 16.5% non-operated working interest in the field. The field has been developed as a subsea satellite of the Britannia field in Blocks 15/29a and 21/4a. First production from Callanish was achieved in 2008.

Dons

The Dons area consists of the Don Southwest, West Don, Conrie and Ythan oil fields. The fields are located in the Northern North Sea area of the UK Continental Shelf, approximately 150km northeast of the Shetland Islands, in water depths of approximately 558 feet (170m). The fields are operated by Enquest with Ithaca Energy a non-operated partner. The fields are in the decommissioning phase with the safe removal of the Northern producer platform and subsea equipment achieved in 2021/22 and the abandonment of the wells as the final activity remaining in the field.

Elgin-Franklin

Elgin-Franklin field is a series of High Pressure, High Temperature gas-condensate reservoirs and is located in the UK Central North Sea, 130 miles east of Aberdeen. The fields are operated by TotalEnergies (46.2%) with ENI (21.9%), Harbour Energy (19.3%), Ithaca Energy (6.1%), NEO Energy (4.4%) and ONE-Dyas (2.2%) holding non-operated interests. Ithaca Energy’s interest was increased from 3.9% to 6.1% through its acquisition of Summit E&P in June 2022.

Enochdhu

The Enochdhu oil field lies 100 miles (160km) northeast of Aberdeen, in the UK Central North Sea, in water depths of approximately 460 feet (140m). The field has been developed as a single subsea well in Block 21/5a and tied back via pipeline to the nearby Callanish subsea manifold and onwards to the Britannia field facilities. Enochdhu achieved first production in June 2015. The field is operated by Chrysaor Limited (50%), with Ithaca Energy owning a 50% non-operated working interest.

Jade

The Jade field is a high-pressure high-temperature gas field located approximately 150 miles south-east of Aberdeen, in the UK Central North Sea. Jade is operated by Harbour Energy (67.5%), with Ithaca Energy (25.5%) and ENI (7.0%) holding non-operated interests. Ithaca Energy’s interest was increased from 19.93% to its current 25.5% through its acquisition of Siccar Point Energy in June 2022.

A recent successful drilling campaign has increased field production to over 70MMscf/d with production from the gas field likely to continue into the next decade.

Mariner

The Mariner field including Cadet and Mariner East is located approximately 100 miles east of the Shetland Islands. The Mariner field came onstream on 15 August 2019. The field is operated by Equinor (65.1%) with NEO Energy (20.0%), ONE-Dyas (6.0%) and Ithaca Energy holding 8.9% non-operated interest. Ithaca Energy acquired its interest through its acquisition of Siccar Point Energy in June 2022.

MonArb

The MonArb area is located in the Central North Sea roughly 128 miles east of Aberdeen. The area consists of nine producing fields covering blocks 22/17n, 22/17s, 22/18n, 22/18a, 22/22a, 22/23a, with production coming from Palaeocene Forties and Upper Jurassic Fulmar sandstone formations. Production is exported via the Forties Pipeline System to Cruden Bay, north of Aberdeen, with gas exported via the CATS pipeline to the CATS terminal at Teeside for processing.

Three platforms in the MonArb area operated by Repsol Sinopec at a water depth of 90m include Montrose Alpha commissioned in 1976, the Arbroath Platform commissioned in 1990, and the Montrose Alpha BLP commissioned in 2017. First production from the area was in 1976 from the Montrose fields, with subsequent production coming from Arbroath (1990), Arkwright (1996), Brechin (2005), Wood (2007), Godwin (2015), Cayley (2017) and Shaw (2017). The MonArb area benefitted from a £2 billion redevelopment project (and step-change in performance) that was completed in 2017.

Ithaca entered the MonArb area through the acquisition of Mauribeni’s interested in 2022. Continued development of the MonArb area is now premised with the addition of wells to maximize field recovery.

Pierce

The Shell operated Pierce oil field is located in Block 23/22a and lies 165 miles (265km) East of Aberdeen, Scotland, in the Central North Sea area of the UK Continental Shelf, in water depths of approximately 262 feet (85m).

The field was discovered in 1975, with first oil achieved in February 1999. Ithaca Energy acquired its 7.48% non-operated working interest in the Pierce field from Sumitomo Corporation in July 2014.

Rosebank

The Rosebank field is located approximately 80 miles north-west of the Shetland Islands. The field was discovered in 2004 and has since been appraised with five wells. Field development is proposed to be accelerated by redeploying the Petrojarl Knarr FPSO. The field is operated by Equinor (40.0%) with Suncor Energy (40.0%) and Ithaca Energy (20%) holding non-operated interests. Ithaca Energy’s interest was acquired through its acquisition of Siccar Point Energy in June 2022.

In September 2023, Ithaca Energy, together with Equinor (the Operator), announced the final investment decision to progress Phase 1 of the Rosebank development on the UK Continental Shelf, together investing $3.8 billion in the development. The North Sea Transition Authority (“NSTA”) granted consent for the development of the field on 27 September 2023.

The Rosebank field is located around 130 kilometres north-west of Shetland. Recoverable resources are estimated at around 300 million barrels of oil from phase 1 and 2, with Phase 1 targeting an estimated 245 million barrels of oil. The field will be developed with subsea wells tied back to a redeployed Floating Production Storage and Offloading vessel (“FPSO”), with first production expected in 2026-2027. The Rosebank field will produce in excess of 21 MMSCF of natural gas every day, the equivalent to the daily use of Aberdeen City.

Schiehallion

The Schiehallion field is located approximately 90 miles west of the Shetland Islands. It was discovered in 1993 with first production in 1998. Schiehallion is operated by BP (33.3%) with Shell (44.9%), Harbour Energy (10.0%) and Ithaca Energy (11.8%) holding non-operated interests. Ithaca Energy acquired its interest through its acquisition of Siccar Point Energy in June 2022.

The Schiehallion reservoir comprises excellent quality stacked Tertiary sands deposited by deep water gravity flows. The use of 4D seismic technologies has enabled better understanding of the field and as a result, the expected ultimate recoverable reserves have substantially increased from 340 million barrels in the original field development plan to over 850 million barrels, with over 450 million barrels of remaining recoverable oil reserves.

In 2011, the Schiehallion co-venturers sanctioned field redevelopment to unlock remaining reserves and extend the life of the field as part of BP’s Quad 204 project. A purpose-built harsh water FPSO, the Glen Lyon, replaced the old Schiehallion FPSO and much of the subsea infrastructure was also replaced. The field resumed production in May 2017. As well as re-using the existing well stock of 44 producers and injectors, an ongoing multi-year drilling programme will add new wells to the field.

West Don

The Dons area consists of the Don Southwest, West Don, Conrie and Ythan oil fields. The fields are located in the Northern North Sea area of the UK Continental Shelf, approximately 150km northeast of the Shetland Islands, in water depths of approximately 558 feet (170m). All the fields produce from the Brent reservoir sequence sandstones.

Ithaca Energy acquired its interests in the Dons oil fields in Block 211/18a and B through the acquisition of the UK-listed company Valiant Petroleum plc in April 2013.

The Don Southwest field is a re-development of part of the former Don field that was discovered in 1976 and first oil from the re-development was achieved in April 2009. EnQuest operates Don Southwest (60%), with Ithaca Energy holding a 40% non-operated working interest.

Potential transformational combination with Eni's UK  business

In March 2024, Ithaca Energy entered into an exclusivity agreement for a potential transformational combination with substantially all of Eni’s UK upstream assets including the recently acquired Neptune Energy assets, excluding certain assets including Eni's CCUS and Irish sea assets.

Eni will contribute its UK business in exchange for the issuance of new Ithaca Energy shares to Eni, with Eni anticipated to hold between 38% and 39% of the enlarged issued share capital of Ithaca Energy following completion. Eni has a well-diversified asset base across 4 key hubs: Elgin Franklin, J-Area, Cygnus, and Seagull and Ithaca Energy is already a partner in the Elgin Franklin and Jade fields.

KeyFacts Energy: Ithaca Energy UK country profile