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UAF team testing geothermal technique Three-year effort is testing whether imaging technology designed for monitoring volcanoes and coal fires can be used for geothermal Eric Lidji For Petroleum News
A team of University of Alaska Fairbanks researchers is testing a technique that could make it cheaper and easier to explore the potential of remote geothermal systems.
The UAF Alaska Center for Energy and Power plans to drill between two and four exploration wells this summer in the Pilgrim Hot Springs region just outside of Nome to test the results of remote airborne imagining work conducted over previous years.
The team is using Geophysical Institute-developed imaging technology originally designed for monitoring volcanoes and underground coal fires to study geothermal systems remotely. If successful, the technique would make it easier to gauge whether a geothermal resource is worth exploring, decreasing the cost of initial ground-based evaluations in remote areas where it can be difficult to bring in equipment by land.
“This is a cheap way to get a first order of magnitude understanding of the resource,” said Gwen Holdmann, project lead and director of the Alaska Center for Energy and Power.
The technique could be useful across Alaska and in other regions around the world.
Three-year program The work this summer is actually one of the final phases in a three-year effort, an attempt to see if on the ground drilling data confirms the conclusions of the remote sensing.
The teams started two years ago by conducting the aerial remote sensing, and returned to the site last year to drill two 500-foot core holes to measure temperature gradients. This summer, crews are drilling deeper wells, around 2,500 feet. The first is already around halfway to total depth. The team is permitting six locations and plans to drill between two and four total exploratory wells this year, depending on the results of the first well.
Once the wells are completed, the team will model the reservoir.
The Pilgrim Hot Springs reservoir is intriguing because it contains a relatively shallow layer of hot water around 75 feet deep sandwiched between layers of much cooler rocks.
“Basically, what we’re trying to do is understand where the hot water is coming from, which is something that has eluded previous evaluations of the site” Holdmann said.
The U.S. Geological Survey is drilling the wells for the Alaska Center for Energy and Power, using a rig previously used for coalbed methane exploration and other operations in Alaska. The project was funded in part by a $3.8 million grant from the U.S. Department of Energy through the American Recovery and Reinvestment Act, and partially with State of Alaska funding through the Renewable Energy Grant Fund.
Returning to older site A UAF-led team previously studied Pilgrim Hot Springs in the late 1970s and early 1980s, surveying the region and drilling six test wells between 150 and 1,000 feet deep. The effort was unable to make a commercial case for geothermal development.
But geothermal technology has improved since that time.
The famous Chena Hot Springs geothermal project northeast of Fairbanks produces power from relatively low temperatures by using a binary system adapted from standard chiller technology. The plant provides a model for generating sustainable power production operations from moderate geothermal systems, such as Pilgrim Hot Springs.
If successful, the project could prompt researchers to take another look at other geothermal systems previously passed over because they were thought to be “too cool.”
Through a grant from the Renewable Energy Grant Fund managed by the Alaska Energy Authority, the UAF team will gauge whether the resource could generate power for the Nome region, or be used more locally to grow food or for other direct-use purposes.
This winter, the team will perform various reservoir modeling and economic analyses to assess various options for development. The property is owned by Unaatuq, LLC, a consortium of locally owned native corporations and non-profit organizations.
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