Study: Amount of water for oil shale production is less than estimated
An oil shale industry producing the equivalent of 1.5 million barrels of oil per day might require significantly less water than had been previously believed, a study suggests.
Much of the water savings could stem from using natural gas to heat shale in place instead of using coal-fired electrical plants the size of those near Craig, the study suggests. Much also depends on the quality and quantity of what is known as “produced water,” or water drawn out of the earth as a byproduct of heating oil shale.
The study offers no assurance that an oil shale industry eventually or ever will take shape, said Greg Trainor, of the Colorado River Basin Roundtable, one of two that joined forces to commission the study by Boulder-based AMEC, a consulting, engineering and project-management company.
It does, however, suggest an oil shale industry could operate with 120,000 acre-feet of water per year, down from previous estimates of 400,000 acre-feet per year.
The assumptions of the report, which forecasts the potential water demand of the industry by 2050, might also turn out to be too rosy, according to Western Resource Advocates, which monitors oil shale developments.
One thing the report underscores is the need for water storage in western Colorado, Glenn Vawter of the National Oil Shale Association said.
“If there is going to be a shale industry, there will definitely be a need for more storage facilities,” Vawter said.
Much of the foundation of the study “represents industry’s hopes,” said David Abelson of Western Resource Advocates, “but with the technologies used in this report being in their infancy, whether these projections come true will not be known for a generation or two.”
Previous studies of the potential water demand of oil shale have been based on the need for a dozen coal-fired power plants to generate electricity to heat shale, but it appears natural gas, an abundant energy source in the Piceance Basin, could run gas-turbine generators to produce the needed electricity, but without the water demand of a coal-fired plant.
That’s one part of the reduced demand for water.
Much of the demand for water could be met through produced water, which could be used for domestic purposes, revegetation and other purposes, Trainor said.
A third factor that might reduce water consumption in western Colorado would be refining elsewhere the kerogen that results from in-situ heating of shale. Refinery capacity is available in Salt Lake City, meaning refineries wouldn’t have to be built in more remote, arid western Colorado.
If produced water couldn’t be used, industry demand for water could rise by some 60,000 acre-feet of water to 180,000 acre-feet, Trainor said. Using coal-fired generation could add 170,000 acre-feet of water back in, bringing total demand up to about 350,00 acre-feet, or just under the previous estimate, Trainor said.
The study also contains “considerable uncertainties ... that leave the door open for actual water needs being nearly three times their projected high end,” Abelson said.
Even under the most optimistic of forecasts, the availability of water is “still going to be a hurdle” for the industry, Vawter said. “This is not something that’s going to happen overnight.”