Scope of INA’s northern Adriatic drilling campaign
Croatian oil and gas company INA has started a €65mn offshore drilling programme in the northern Adriatic. The project targets five new production wells as Croatia seeks to slow the decline of domestic gas output. The campaign is structured around drilling multiple wells rather than a single development.
Ana-4 DIR well testing and expected 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 delivered a combined gas flow of approximately 160,000 cubic metres per day. Based on that test rate, the well could produce the equivalent of about 58mn cubic metres annually if maintained continuously.
Sustained production will depend on reservoir pressure, decline rates, processing capacity and the results of extended testing. The initial flow is described as material relative to Croatia’s current monthly domestic production of around 60mn cubic metres. Extended testing is expected to support a clearer view of longer-term performance.
Connection plan and data for reserve updates
INA plans to connect Ana-4 DIR to its existing offshore production network before longer-duration tests begin. Longer-duration testing is intended to clean the reservoirs, establish sustainable production rates and generate data for updated reserve estimates. The difference between initial test flow and recoverable commercial output is expected to be central to the project’s economics.
The wider campaign involves drilling five wells, with an average investment envelope of approximately €13mn per well. Actual spending is expected to vary depending on depth, completion design and connection requirements. Drilling operations are being carried out using existing offshore systems where applicable.
Rig operations and link to IKA JZ-6 DIR location
Drilling was performed 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.
Implications for Croatia’s gas balance and import needs
Croatia’s existing Adriatic fields are described as mature, with new wells tied into established platforms and pipelines generally able to be developed faster and at lower cost than standalone discoveries. Commercial returns are expected to depend on well productivity and the remaining life of the surrounding network. The programme is not expected to remove Croatia’s need for imported gas.
Imports reached 277mn cubic metres in May, compared with domestic production of 60mn cubic metres. The campaign is positioned to reduce the pace at which import dependence grows while preserving value in INA’s existing offshore assets.
