Hydrocarbon Well Testing as Part of Geothermal Exploration in Hungary

Abstract

MOL Hungarian Oil & Gas Plc. organized a consortium to develop a geothermal pilot project to explore power plant opportunities offered by geothermal resources in Hungary. The technical concept included utilization of existing abandoned hydrocarbon wells in the southwestern part of Hungary for producing and reinjecting thermal water. The exact flow rate was unknown because the exploratory drilling initially focused on hydrocarbons; therefore, thermal water production and reinjection tests were necessary.

After the wells were completed, two decommissioned hydrocarbon wells were converted to thermal water production or reinjection wells as part of the testing phase. Thermal water was extracted from the wells into a pit near the well. Then the produced thermal water was reinjected back to its own aquifer through the same well. The collected data were then analyzed.

Highlighting this new approach in Hungarian geothermal exploration are the utilization of abandoned hydrocarbon wells, the establishment of an international consortium for thermal water exploration, as well as the unusual depth of the wells, the fairly high temperature, and the focus on power plant establishment. This pilot project started a new segment in the history of Hungarian geothermal exploration. Based on the project results, the consortium members established a joint company for developing further geothermal projects.