Geothermal reinjection in sedimentary basins

Abstract

Low-temperature sedimentary geothermal systems belong to one of the main types of geothermal resources worldwide. Experience from reinjection practices is important to understand the main characteristic parameters of a geothermal system, in order to avoid a failure of its utilization, e.g. through overexploitation. This report presents examples of good reinjection practices in sedimentary systems in different European countries, where reinjection is a part of the sustainable management of geothermal resources. Besides this, the report presents information on the geothermal potential in Romania, with main emphasis on reservoirs and geothermal specifics in the Balotesti area, north of the capital of Bucharest. The experience of countries such as France and Germany has shown that reinjection should be planned simultaneously with production for geothermal district heating systems. The lessons learned in these countries should be the basis of developing geothermal reinjection in countries with limited experience of reinjection, such as in Romania. The reinjection design should focus on maintaining the reservoir pressure, but it is also important to predict the long-term thermal breakthrough time for the production wells used. The report also presents recommendations aimed at supporting a considerable increase in the utilization of geothermal resources in Romania as well as their sustainable management.