Old oil and gas wells can find a second life to produce clean energy

As countries seek In order to obtain a much-needed supply of clean, reliable energy, some are looking to an unconventional source: abandoned oil and gas wells harnessed for geothermal heat.

Millions of inactive wells are scattered across the United States, remnants of previous eras of fossil fuel production. Many of the sites have no official owner, and many still pollute groundwater and leak methane, which traps heat. The country has barely scratched the surface in dealing with this problem.

Policymakers in both Republican- and Democratic-led states are exploring whether these sites could instead be converted into new geothermal wells. After all, the holes had already been dug in the ground. Areas undergoing extensive oil and gas development have rich subsurface data that geothermal companies need to determine where and how to build their carbon-neutral systems.

This concept is relatively new and largely untested, although scientists and startups are working to change that. Countries are also laying the groundwork for action by removing regulatory hurdles and launching in-depth studies.

And in Oklahoma, the state Senate is considering a bill that would create a process for companies to buy abandoned oil and gas wells and repurpose them for geothermal energy or underground energy storage. The state of Oklahoma has identified more than 20,000 wells of this type, and state regulators estimate that filling them all will take 235 years and hundreds of millions of dollars. Repairing a single old well can cost $75,000 to $150,000 or more, by some accounts, depending on where it is located and how complex the cleanup is.

The Well Reuse Act, which passed the Oklahoma House of Representatives in March, is modeled on a similar law adopted by New Mexico last year to address its more than 2,000 orphan wells.

The Oklahoma bill “recognizes that these wells are a liability, and that there might be a way to turn them into some sort of revenue generator and give them value,” said Dave Tragethon, communications director for the nonprofit Well Done Foundation, which works to find abandoned oil and gas wells across the country. “And if there is value, it means there is more willingness to address it and more opportunities to raise funding.”

In Alabama, lawmakers passed a law last month that allows the state to approve and regulate the conversion of oil and gas wells to take advantage of alternative energy resources such as geothermal energy. North Dakota adopted a bill last year requiring the legislature to study the feasibility of using non-producing wells to generate geothermal energy. And in Colorado, state agencies have just launched a technical study to evaluate the potential for reusing old wells for geothermal energy development and carbon capture and sequestration.

These efforts reflect growing bipartisan support for geothermal energy, which has largely remained untouched by the Trump administration’s efforts to block renewable energy projects. The energy supplier has the potential to help meet the country’s growing energy demand while reducing global warming emissions from electricity and heating.

Converting wells is tempting but complicated

Geothermal systems work by circulating fluids underground to capture natural heat, which can then be used to drive turbines to generate electricity or to directly warm air and water in buildings. The industry is gaining momentum thanks to recent advances in drilling methods and technologies that make it technically possible or financially feasible to access geothermal energy in more places.

Many of these breakthroughs have come from the oil and gas industry, whose skilled workforce of drilling engineers and geoscientists, and significant resources, have helped launch startups and deploy cutting-edge systems. However, most of this expertise and funding is being pumped into building new projects, not into figuring out how to retool leaky wells left by previous generations.