Programme scope and new well targets
Croatian oil and gas company INA has started a €65mn offshore drilling programme in the northern Adriatic. The campaign targets five new production wells as Croatia seeks to slow the decline of domestic gas output. The first phase includes completion work on Ana-4 DIR within an existing production area.
Ana-4 DIR completion and initial test results
Ana-4 DIR has been completed 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. INA said the results support a preliminary assessment of commercial viability.
If the test rate were maintained continuously, the well could produce the equivalent of about 58mn cubic metres annually. Sustained output would 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.
Connection plan and longer-duration testing
INA plans to connect Ana-4 DIR to its existing offshore production network before longer-duration tests begin. The extended testing is intended to clean the reservoirs, establish sustainable production rates and generate data for updated reserve estimates. The project’s economics will distinguish between initial test flow and recoverable commercial output.
Drilling operations and infrastructure context
The broader campaign is designed to drill five wells, with an average investment envelope of approximately €13mn per well, although actual costs are expected to vary by depth, completion design and connection requirements. Drilling was carried out 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 positioned around mature Adriatic fields, where new wells tied into established platforms and pipelines can generally be developed faster and at lower cost than standalone discoveries. Commercial returns will depend on well productivity and the remaining life of the surrounding network.
Implications for Croatia’s import needs
The campaign 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 additional output can reduce the rate at which import dependence grows while supporting the value of INA’s existing offshore assets.
