More recently, Petrolern LLC – an Atlanta-based service and technology firm specializing in subsurface engineering and downhole tools – has advanced another idea: repurpose some of the orphaned oil and gas wells to produce geothermal energy. The company has developed a system called “ConvertDeck” that it maintains efficiently evaluates large numbers of orphaned wells to determine which are likely good candidates for geothermal conversion. “Geothermal energy has up to now been a small contributor to U.S. and global energy,” Alan J. Cohen, technology partnerships director with Petrolern, told Rigzone, adding the resource has primarily been exploited in high-temperature volcanic belts in certain regions of the globe. “Drilling new geothermal wells is very expensive and can be up to 50% of the total project cost. Repurposing lower-temperature oil industry wells in sedimentary formations provides a valuable new source of geothermal energy.”