Can abandoned oil wells become geothermal energy sources?

Across the U.S., states are starting to explore an unusual energy idea: turning abandoned oil and gas wells into sources of geothermal energy. 

On paper, it is an appealing solution. The U.S. has millions of inactive oil and gas wells, many of them leaking methane, polluting groundwater, and costing states huge amounts of money to clean up and seal. Now, some policymakers and researchers are asking whether those same wells could be reused to provide clean heat and, in some cases, even generate electricity instead of remaining expensive environmental hazards.