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Jim Bridger power plant

Steam rises from the huge boiler units at the Jim Bridger power plant east of Rock Springs, Wyo., in 2006. An ongoing state carbon sequestration study is looking at the possibility of taking the CO2 emissions produced at the plant and re-injecting them into deep saline aquifers within the nearby Rock Springs Uplift.

JEFF GEARINO/Casper Star-Tribune

ROCK SPRINGS, Wyo. — On paper, the small stretch of the Red Desert east of Rock Springs seems the perfect spot for Wyoming's first effort to capture and store billions of tons of carbon dioxide underground.

The 25-square-mile site sits over saline formations located deep underground in the Rock Springs Uplift. The formations contain porous limestone and sandstone rock to hold the gas and outstanding seals to keep the gas from escaping.

The proposed site is also adjacent to the coal-fired Jim Bridger Power Plant, the state's largest emitter of CO2 and a potential source for the carbon dioxide that would be re-injected.

And there's no previous oil and gas development to conflict with.

State officials expect an ongoing $17 million study to ultimately determine if the Rock Springs Uplift really is Wyoming's most promising potential carbon sequestration site. The state's Carbon Management Institute has begun a multiyear project to characterize and test the storage potential of the Rock Springs Uplift.

Early indications from previously obtained data seems promising, CMI officials said.

“There appears to be tremendous potential for storing CO2 in the Rock Springs Uplift,” CMI outreach coordinator Lynne Boomgaarden told a large crowd of residents and government officials during a town meeting here Wednesday night.

“If we can store CO2 securely, we can reduce greenhouse gas levels,” Boomgaarden said. “And for Wyoming, that is particularly important to the viability of the state's coal industry. We're going to see if this is a suitable CO2 storage site.”

Carbon capture involves separating CO2 from emissions from sources such as coal-fired power plants, and transporting the gas to a storage location.

Carbon sequestration is the underground storage of CO2 in a way that permanently separates it from the atmosphere.

The Carbon Management Institute — a part of the University of Wyoming's School of Energy Resources — is researching the carbon storage part of the equation, officials said.

First phase

Researchers involved in the first phase of the Wyoming Carbon Underground Storage Project are studying two deep saline aquifers in the Rock Springs Uplift for its potential to begin a pilot or commercial-scale CO2 sequestration project.

The three-year effort will include the drilling of a deep test well and the completion of a 3-D seismic mapping study that will be used to produce a comprehensive description of the aquifers, CMI director Ron Surdam said.

Surdam said preliminary data from prior research indicates that the Rock Springs Uplift can store 26 billion tons of CO2 per year, or about 750 million tons over 50 years.

That's about 485 years worth of Wyoming's total current CO2 emissions, he said.

The site is next to the state's largest source of CO2 emissions, the Jim Bridger Power Plant. The facility is located about 25 miles east of Rock Springs in Sweetwater County and north of Point of Rocks.

The study will look at the feasibility of injecting approximately 15 million tons of CO2 into the uplift's saline aquifers. That's the same amount of carbon dioxide emissions released each year from the Jim Bridger Power Plant.

Surdam said the target sandstone and limestone formations holding the saline aquifers lie within the Weber/Tensleep and Madison/Big Horn formations. The formations are 11,600 to 12,870 feet underground.

“This is a very recent uplift in terms of geologic history ... about 43 or 44 million years old ... and the fact that it's relatively new gives it special characteristics that we think make it an outstanding geological sequestration site,” he said.

“There has also been some previous (fossil fuel) production (in the area), but little or no production on the Rock Springs Uplift ... so we're not looking at conflicts with (existing fossil fuel) production and sequestration,” Surdam said.

Baker Hughes oilfield services officials are beginning work on a test well that will be drilled to about 14,000 feet deep to collect various samples of rock layers and sediments.

Water

The targeted saline aquifers all lie below underground safe drinking water sources, Surdam said.

The storage formations are also overlain by a series of sealing caprocks, which early research indicates is solid enough to prevent the migration of gases.

Saline reservoirs are deep underground geologic formations that contain highly mineralized brines, or salt water, that is unsuitable for drinking, agriculture use or industrial use.

Surdam said one of the most significant obstacles to implementing a commercial-scale CO2 sequestration system in deep saline reservoirs is the management of the displaced salt water.

He estimated about 6 billion barrels of brine could be produced over a 50-year carbon sequestration project life on the uplift.

Surdam said preliminary research indicates that in order to prevent CO2 leakage or escape, any CO2 injection operation on the Rock Springs Uplift will have to bring the displaced brine to the surface and treat it for industrial, agricultural and residential use.

The study will provide new characterization data that in turn will be used to develop an efficient, customized water treatment facility.

“The biggest challenge ... will be to construct a customized system that can treat that brine and solve that displaced water problem,” Surdam said.

Contact Jeff Gearino at gearino@tribcsp.com or 307-875-5359.

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