An idea that has the potential to create a new clean energy revenue stream from stranded oil assets is being pioneered in Alberta.
Oil wells that have been abandoned can be tapped to supply limitless geothermal heating to buildings above them, supplying heating for greenhouses to grow fresh fruit and vegetables in winter.
Alberta Energy — the government agency that ensures that development of the province’s energy resources benefits all Albertans — is looking into facilitating conversion of disused oil and gas wells into geothermal systems as a partial solution to the province’s abandoned well crisis.
The world’s first carbon neutral museum has been set up to showcase the concept and to amass enough data to determine the cost/benefit of oil-to-geothermal heat conversion in general worldwide.
“The Living Energy Project demonstrates the potential to heat greenhouses, although it will actually heat a museum, which will become the world’s first carbon neutral oil museum,” Nick Wilson, director of Living Energy Project, told Renewable Energy World.
More than 151,000 oil wells have been decommissioned in Alberta alone, and 78,000 more are now dormant as a result of low oil prices. If even 10 percent of just Alberta’s dormant wells were converted to geothermal-heated greenhouses, that would create up to 5,000 permanent year round agricultural jobs, according to Wilson.
The pilot project will record the heat produced and the power used by the geothermal system as well as model the output at different depth wells in various geologic types, and factor in variables like the distances to propane and diesel distribution, at high and low oil prices, in order to compare all the costs and benefits to determine the cost-effectiveness of the conversion from oil to geothermal.
Retrain Local Oil Workers to Geothermal
The opportunities for crossovers from one energy industry to another are clear. Jason Edwards, CEO of Sundial Energy, was himself a veteran of Alberta’s oil industry. His firm is handling the geothermal conversion for the Living Energy Project museum, which showcases Alberta’s various energy resources.
According to Edwards, many of the local oil service firms that have long served the oil industry would continue to have work in making this switch to renewable geothermal energy, because their existing oil industry skills are the same skills needed to adapt the abandoned oil infrastructure to geothermal. He says the project is intended to be “open source” — that is to share the data with researchers, scientists and engineers around the world.
This project is not geothermal electricity co-generation at an operating oil field, another area of interest supported by the U.S. Department of Energy in the U.S. since 2008. Researchers in North Dakota began operating the first commercial geothermal facility at an operational oil field in April.
This kind of geothermal energy being explored in Alberta would be for direct heating; simply running the naturally heated water in a closed loop system piped throughout the buildings above each abandoned well.
“Any depleted oil well could be reused to provide heating for any kind of commercial or industrial building, or even as district heating,” Edwards said.
The repurposing of the well makes a new use of abandoned industrial infrastructure that is left in the ground when oil wells go dry.
The reused part of the oil well is the interior of a steel casing about a foot wide that goes down as much as 3,000 feet. When an oil well is abandoned, this steel tube is then sealed by pouring about 40 feet of concrete at the bottom. The tube is capped off at the top as well, about 10 feet below ground.
This wasted industrial infrastructure left behind — steel tubing left invisibly below ground — is what Wilson proposes to repurpose to provide geothermal heating.
To make the conversion, the workers would insert a small polyethylene tube within the steel casing that is left behind in the ground when a well goes dry. The plastic tubing would go down and loop back up inside the same steel casing. The water inside this tube would then be fed throughout the building to heat a greenhouse with radiant heat.
The heat at that depth is natural. It is not affected by the oil depletion, it would remain at a constant temperature and heat the water in each cycle.