Use of abandoned oil wells in geothermal systems in Turkey

Abstract

Human beings have been benefiting from geothermal energy for different uses since the dawn of civilization in many parts of the world. One of the earliest uses of geothermal energy was for heating and it was used extensively by Romans in Turkey. The Aegean region is favored with a large number of thermal springs known since ancient times. However, it was in the twentieth century that geothermal energy was first used on a large scale for direct use applications and electricity generation. The country's installed heat capacity is 3322.3 MWt for direct use and 1347 MWe for power production. Also, many drilled wells to extract oil or natural gas were abandoned for various reasons in the southeast of Turkey. Some of the oil fields have heat content that can be used for geothermal energy. Some even have hot fluid in the reservoir. This paper presents an investigation into how to use geothermal energy in abandoned oil and natural gas wells. Methods used to generate geothermal energy from abandoned oil fields other than conventional geothermal energy production are examined. Downhole heat exchangers can be used to extract heat without producing geothermal fluid which decrease gas emissions to the atmosphere and energy need for reinjection, from the abandoned oil wells to generate electricity or direct use applications. Using this method, it is possible to use abandoned wells in southeastern Turkey where this energy improves the economy of the region.