Croatian oil and gas company INA has started a €65mn offshore drilling programme in the northern Adriatic, targeting five new production wells as Croatia seeks to slow the decline of domestic gas output.
The first well, Ana-4 DIR, has been completed in an existing production area at a final depth of 1,282 metres. Initial testing across three reservoirs produced a combined gas flow of approximately 160,000 cubic metres a day, supporting a preliminary assessment that the well is commercially viable.
Were that test rate maintained continuously, the well could produce the equivalent of about 58mn cubic metres annually. Sustained output will depend on reservoir pressure, decline rates, processing capacity and the results of extended testing, but the initial flow is material compared with Croatia’s current monthly domestic production of around 60mn cubic metres.
INA plans to connect Ana-4 DIR to its existing offshore production network before conducting longer-duration tests. These will clean the reservoirs, establish sustainable production rates and provide data for updated reserve estimates. The distinction between initial test flow and recoverable commercial output will be central to the project’s economics.
The wider campaign is designed to drill five wells, implying an average investment envelope of approximately €13mn per well, although actual expenditure will differ depending on depth, completion design and connection requirements.
Drilling was undertaken using the Labin offshore rig operated by INA subsidiary Crosco. The rig is expected to move next to the IKA JZ-6 DIR location. INA reported that the first drilling operation was completed without environmental incidents.
The programme is significant because Croatia’s existing Adriatic fields are mature. New wells tied into established platforms and pipelines can generally be developed faster and at lower cost than standalone discoveries, as much of the production infrastructure is already available. Commercial returns will depend on well productivity and the remaining life of the surrounding network.
The campaign will not eliminate Croatia’s need for imported gas, which reached 277mn cubic metres in May against domestic production of 60mn cubic metres. It can, however, reduce the rate at which import dependence grows and preserve the value of INA’s existing offshore assets.
