Site preparation ongoing for geothermal drilling in Osijek, Croatia
Preparation of drill site of the geothermal exploration well in Osijek, Croatia (source: video screenshot, Croatian Hydrocarbon Agency)
Carlo Cariaga
28 May 2025
The site for drilling of the geothermal exploration well in Osijek, Croatia is currently being prepared, with drilling expected to start by Q2-Q3 2025.
Since early April 2025, construction work has been ongoing at the drilling site of the Osijek GT-1 exploratory geothermal well, located in the settlement of Tenja, near the city of Osijek in Croatia. Drilling is expected to begin by late Q2-Q3 of this year.
The Osijek GT-1 well will be the second geothermal well to be funded under Croatia’s National Recovery and Resilience Plan. The first is the Velika Gorica GT-1 geothermal exploration well, which started drilling in February 2025. A separate update provided by the Croatian Hydrocarbon Agency (Agencija za ugljikovodike / AZU) states that the well has reached a depth of 800 meters (against a target of 2900 meters) as of early March 2025.
The Osijek GT-1 well is planned to reach a depth of 2,000 meters (±200 m), targeting a predicted Neogene reservoir where water temperatures are expected to reach approximately 100 °C at around 1,900 meters. The project aims to confirm the geothermal potential of this part of the Pannonian Basin, with a particular emphasis on its application in district heating.
In May 2024, AZU awarded the drilling and well design contracts for four geothermal sites CROSCO, naftni servisi, doo (Crosco). Velika Gorica and Osijek is included in these four sites, along with Zaprešic and Vinkovci.
Source: Croatian Hydrocarbon Agency
