Common geothermal well design and a case study of the low-temperature geothermal reservoir in Otopeni, Romania

Abstract

The report describes a design of a well for the low-temperature geothermal, Therme Balotesti reservoir in Otopeni in the Romanian Plain. The well was designed by specialists with great experience in the field using the main features from the offset wells as references. The report includes assumed design calculation regarding the drill string design and casing design characteristics based on the information gathered from various published papers and drilling handbooks. More information for the project could not be accessed due to confidentiality with regard to technical information. Romania has the third largest potential geothermal capacity in Europe after Greece and Italy. The development of direct utilization of geothermal resources in Romania is however not far advanced due to high investments costs and the very low price of hydrocarbons. Exploration drilling for geothermal resources in Romania started in the 1960s. Over 200 drilled wells for hydrocarbons explorations have been drilled to depths between 800 and 3000 m, encountering geothermal resources of low and medium enthalpy (40-120°C). Thermal springs are the only visible manifestations of geothermal resources across the country. The main direct uses of geothermal heat are district heating and individual space heating and health and recreational bathing. Geothermal energy is also used for greenhouse heating, fish farming, industrial processes and drying. Currently further geothermal development is facing unfavourable conditions as the international market prices for fossil fuels and domestic oil and gas production have dropped dramatically.