Reply #5: Coaxing oil from huge U.S. shale deposits

[ozymandius]

Underneath the high, scrub-covered rangeland of northwest Colorado is the world's biggest oil field. Getting the oil out of the ground, however, is one of the world's biggest headaches.

The area's deposits of oil shale are believed to be larger than all the oil reserves of the Middle East. But past attempts to get at this oil locked in tarry rock have cost billions of dollars and raised the prospect of strip-mining large areas of the Rocky Mountain West.

Now, as the federal government makes another push to develop oil shale, Shell and other companies say they have developed techniques that may extract this treasure with much less environmental impact.

Shell's project is stunningly complex. Instead of strip-mining the rock and then processing it, Shell plans to superheat huge underground areas for several years, gradually percolating oil out of the stone and pumping it to the surface.

http://www.sfgate.com/cgi-bin/article.cgi?file=/c/a/2006/09/04/MNGIEKV0D41.DTL