Proceedings World Geothermal Congress 2010 Bali, Indonesia, 25-29 April 2010 1 Geothermal adaptation of abandoned hydrocarbon infrastructure – an option for the oil industry to extend reservoir utilization into the area of renewable energy Wolfgang Straka 1 , Gregor Götzl 2 , Leopold Bräuer 3 , Robert Faber 4 , Karl Gollob 5 , Piotr Lipiarski 2 , Roman Markiewicz 6 , Karl Ponweiser 7 , Christian Schmid 5 , Eva Wegerer 8 , Godfrid Wessely 3 1 Univ. of Natural Resources and Applied Life Sciences, Inst. for Applied Geology, Peter Jordan-Strasse 70, A-1190 Wien, Austria wolfgang.straka@boku.ac.at 2 Geological Survey of Austria, Neulinggasse 38, A-1030 Wien, Austria gregor.goetzl@geologie.ac.at 3 OMV Exploration & Production, Trabrennstrasse 6–8, 1020 Wien, Austria leopold.braeuer@omv.com 4 TerraMath Geoscientific Software, Hauptstrasse 59, 3021 Pressbaum, Austria robert.faber@terramath.com 5 Dipl.Ing. Dr. Christian Schmid, Civil Engineer for Hydrocarbon Technology, Grüner Wald 12, 4810 Gmunden, Austria christian.schmid@unileoben.ac.at 6 Geotechnik Adam ZT GmbH, Wiener Strasse 66–72/15/4, 2345 Brunn am Gebirge, Austria markiewicz@geotechnik-adam.at 7 Vienna University of Technology, Inst. of Thermodynamics and Energy Conversion, Getreidemarkt 9/302, 1060 Wien, Austria karl.ponweiser@tuwien.ac.at 8 University of Leoben, Department of Applied Geosciences and Geophysics, Peter Tunner-Strasse 5/I, 8700 Leoben, Austria eva.wegerer@mu-leoben.at Keywords: Direct use, deep borehole heat exchanger, hydrocarbon well, heat pump, Geothermal Planning Tool, OMVTHERMAL, Vienna Basin, Austria. ABSTRACT Hydrocarbon wells are usually liquidated at the end of their life time but could be used instead for geothermal purposes, if potential heat consumers are at hand nearby. Common liquidation practice and retrofitting costs are rather contrary to the realization of such opportunities. In the future, by using inoperative but still not liquidated wells, chances may open up of extending the life time of some hydrocarbon fields by extracting renewable energy from existing wells. The feasibility of this approach, by using deep borehole heat exchanger technology, was tested for the area of the Vienna Basin, Austria, a major hydrocarbon source in Central Europe, on behalf of the Austrian oil company OMV. 270 wells were investigated. The results show that under local thermal and economic conditions it is difficult to achieve return of investment even on a long-term basis (30 yrs) for all but very few liquidated wells and for most wells currently still in service, too. This is especially true if a specialized company has to be contracted to operate the heat supply network. Given the prime cost for heat that network operators commonly accept (< 25 Euro/MWh) the thermal regime of the investigated area would have to be on the order of at least 160 mW/m 2 of terrestrial heat flow density, corresponding to geothermal gradients of 70 to 80 °C/km. In Europe at least there are very few areas where such conditions prevail. For future work, a software tool (Geothermal Planning Tool) developed for the project and integrating the complete set of necessary technical and economic parameters and calculations, shall be applied to other regions where conditions are more favorable. 1. INTRODUCTION Deep borehole heat exchangers (DBHE) seem to offer an attractive way, in many places, to supply local housing or institutions (public buildings, enterprises, greenhouses, etc.) with heat for direct use. Figure 1: Area of interest and locations of investigated hydrocarbon wells.