Word: rocks
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Dates: during 1970-1979
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Shale drillers know where to find their fuel, but they differ on the best way to get it out. Essentially, shale rock must be "cooked" at 900° F so that the kerogen can be vaporized and extracted. Two processes have been developed to do this...
...above-ground method in which the shale is "distilled" in somewhat the same way that moonshiners extract alcohol from corn mash. After the shale is mined, the rock is crushed. Union Oil then moves shale chunks through a towering surface retort, where hot gases heat it to release the kerogen. Colony uses a different process: it cooks finely ground shale in giant drums by mixing the marl with superheated, marble-size ceramic balls that distribute the temperature evenly and vaporize the kerogen. The balls are then separated from the spent shale by a screen, reheated and used again...
...least 2,000 chambers connected by tunnels under a 5,000-acre shale tract leased from the Government. The chambers, each about the size of a football field and 250 ft. to 300 ft. high, are created by drilling parallel tunnels leading from a vertical mineshaft into the rock at two different depths. The shale in between is then reduced to rubble by explosions in both the top and bottom. Each chamber is sealed, and pilot-light burners are lowered to start cooking the rock. Kerogen released from the shale settles to the bottom of the chamber and is piped...
They claim that their water requirements would be reasonable. Company officials also say that the underground cooking process seals the chambers, actually fuses the rock, and prevents salts from leaching into ground water. Firms plan to contour the piles of leftover shale rubble and to plant them with local wild flowers and grasses; tests have shown good results...
Although the first shale patent was granted in England in 1694 and called for distilling "oyle from a kind of stone," oil from the dark, veined rock so far has not been developed primarily because conventional petroleum has always been cheaper. Now, at last, economic necessity and innovative technology may lead to tapping the vast potential of shale...