UK-based Energean, in partnership with INA – INDUSTRIJA NAFTE, has announced the final investment decision (FID) to develop the Irena gas field offshore Croatia.  

The Irena field is part of the Izabela concession, operated by Edina, a joint venture (JV) equally owned by Energean and INA, a Croatian oil and gas company.    

Its development plan includes a single platform tied-back to existing infrastructure at the Izabela field. 

Energean holds a 70% working interest in the concession, which is located in shallow waters at a depth of approximately 45m.  

The field's P50 reserves are estimated at around 30.5 billion cubic feet gross, equivalent to 5.4 million barrels of oil equivalent. 

Energean Croatia country manager Francesco Federici said: “We are thrilled to move forward with the development of the Irena gas field. This FID underscores Energean’s commitment to advancing natural resource development in Croatia and the wider Adriatic region.  

“This is a strategic investment, and we extend our gratitude to our partner, INA, for their fruitful collaboration over the years and look forward to continued success together.”  

INA operating director of exploration and production Josip Bubnić added: “The decision to invest in the development of the Irena gas field is another important step in advancing our strategy of strengthening domestic oil and gas production and ensuring Croatia’s long-term energy security.  

“We are investing with a clear vision – to enhance energy supply security and maintain our leadership position in the region.” 

The total estimated capital expenditure for the Irena project stands at €71m ($81.2m), with Energean's share amounting to €50m (£43.23m), reflecting its 70% working interest.  

Energean's net entitlement gas will be sold under its long-term gas sales agreement with INA. 

The Irena gas field is expected to commence production in the first half of 2027, with peak production forecast at between eight and ten million standard cubic feet per day gross, equivalent to 1,400–1,700 barrels of oil equivalent per day.