Deep in West Texas, an old oil field is nearing the end of its commercial life. But a startup recently spent a month at the site producing a new energy source: clean, ultra low-carbon hydrogen.
Eclipse, the startup, uses microbes to break down oil in end-of-life wells, releasing hydrogen that can be brought to the surface using existing infrastructure. In the pilot, the company generated hydrogen for 30 days straight before stopping the test. But the company says that old oil field projects like this have the potential to produce hydrogen for 10-20 years—and can make it cheap enough that it could be used to produce clean, baseload power for the electric grid.
There’s an abundant supply of hydrogen in oil fields. “When you produce these oil fields, you’re lucky if you produce 40% of the oil,” says Eclipse’s CEO, Prabhdeep Singh Sekhon, who previously worked in the oil and gas industry. “There’s still a tremendous amount of hydrocarbon in the ground; it’s just not economic to produce. If there’s hydrocarbon, that also inherently means there’s also hydrogen.”
Mining old oil fields for clean energy
Other approaches to clean hydrogen have struggled. The promise is big: Hydrogen emits only water vapor when it’s burned, and it could slash emissions in everything from steel production to ships. But it’s hard to make affordably. Green hydrogen, which uses renewable electricity to split water, is expensive and water intensive. Hydrogen is traditionally made with natural gas, and it’s also expensive to capture carbon in that approach. “Natural” or geologic hydrogen, which looks for reservoirs of hydrogen that are trapped underground, hasn’t yet proven that it’s viable.
Turning to old oil wells could help. Microbes are the key to unlocking the hydrogen. Eclipse built a huge database of microbes found in oil fields, and created its own mix of the microbes to capture the hydrogen from the oil remaining in abandoned wells. The company injects microbes into reservoirs, where the microbes “eat” the oil and release hydrogen gas. (It’s worth noting that the process also releases CO2; the company says that some CO2 stays underground, and emissions can be captured.)
Hydrogen, a lightweight molecule, flows through the reservoirs and can be produced through the wells that are in place. In the pilot, when the company injected microbes in one well, the hydrogen also flowed to a second well around 600 feet away. The company performed a smaller pilot last year in California, but says that the Texas pilot proves that the process works under more challenging geological and chemical conditions.
Unlike natural hydrogen, the approach doesn’t require expensive exploration. It’s already clear where the hydrogen is. And it can use existing infrastructure. “You have billions of dollars in a field that’s already been deployed—the wells are drilled, the surface facilities are installed, the [rights-of-way] are there,” says Sekhon. That reduces the time to deploy a project, he says, along with the cost of production.
The underlying technology still needs to be optimized for commercial use. Scaling up could be a challenge, says Geoffrey Ellis, a researcher who studied geologic hydrogen at the U.S. Geological Survey and now teaches at Stanford. But “the resource potential is enormous,” he says. “There’s a lot of hydrocarbons in the subsurface that are unrecoverable. If we can convert that economically into hydrogen, that would be a game changer.”
From data centers to fertilizer
The approach is appealing for oil and gas companies, since old oil fields that would otherwise be a liability—with wells that have to be plugged and abandoned—can suddenly find a new life. “For an operator, a field that’s about to become a cost can become a source of revenue, its productive life is extended, and plugging costs are pushed out,” says Depinder Sandhu, executive VP and chief commercial officer of Weatherford, an oil field services company that partnered on the project.
The process works best with wells that haven’t yet been plugged, says Sandhu. For it to scale up, there would need to be a clear regulatory path for operators to switch to hydrogen production rather than plugging an old well. “If we get the economics, execution model and policy right, this stops being a pilot story and becomes a way to manage end-of-life assets across the industry,” he says.
An independent analysis from the energy consulting group Wood found that when the company scales up, the cost of its hydrogen could be as low as 56 cents per kilogram, potentially making it the cheapest way to make hydrogen. Right now, hydrogen made from natural gas is commonly used to make fertilizer. Eclipse’s clean hydrogen could also be used to make fertilizer—a major source of greenhouse gas emissions—but the low cost means that it could also be used more broadly, including for electricity.
The company is forming partnerships now with data center developers that want to build next to a power source, says Sekhon. It’s also evaluating partnerships to make fuel for heavy-duty transportation, industrial heat, or feedstock for fertilizer and other chemicals. “Our goal is in the next two to three years that we have a commercial project,” Sekhon says.