Tuesday 21 April 2009

new york times - april 2 2009

Shale Oil Estimates Grow; Likelihood of Extraction, Not So Much
By JAD MOUAWAD

The United States Geological Survey says there’s more oil shale out there than once thought.
While the Obama administration seeks to encourage cleaner energy sources, government geologists have significantly raised their estimates of how much oil is trapped in the shale rocks of Colorado’s Piceance Basin.

Back in 1989, government geologists had assessed the reserves at about one trillion barrels. But in a technical announcement Tuesday, the United States Geological Survey estimated that oil shale resources were 50 percent greater — or some 1.525 trillion barrels.

That may seem like a lot (it’s nearly six times the oil reserves of Saudi Arabia), but the reality is a bit more complicated. As the government notes, the development of the shale rocks “has significant technological and environmental challenges.”

Among them: there exists no economical method for extracting oil from these rocks in the United States today.


Indeed, oil shale does not actually contain crude oil but something called kerogen, which is an organic precursor to oil. In an energy-intensive extraction process, the rocks must be heated to 530 to 930 degrees Fahrenheit, and huge quantities of water must be driven underground at high pressure to melt the rocks and extract the kerogen for processing into shale oil.

Another problem is the presence of large quantities of nahcolite — a mineral often embedded in oil shale deposits that produces copious carbon dioxide when heated during oil shale processing.

The Piceance Basin contains one of the thickest and richest oil shale deposits in the world and is the focus of most continuing oil shale research and development extraction projects in the United States — though few expect full-scale development to happen anytime soon.

One of the first decisions by Ken Salazar, the new secretary of the interior, was to reverse a last-minute decision by the Bush administration to open up Colorado’s oil shale for development. Mr. Salazar stressed the need for “continued research” on the matter.

No comments:

Post a Comment