Word: shale
(lookup in dictionary)
(lookup stats)
Dates: during 1970-1979
Sort By: most recent first
(reverse)
Actually, "shale oil" is neither shale nor oil. The rock is marl, a variety of limestone laced with a solid fossil fuel called kerogen. The kerogen was deposited 40 million years ago in the form of millions of tons of vegetable matter that collected on the bottom of a mammoth freshwater lake that then covered Utah, Wyoming and Colorado. But these lake-bed accumulations were never subjected to temperatures as high as 300° F and to extreme pressures that in time created underground deposits of readily usable liquid oil and natural gas. Now man must finish nature...
...years shale oil remained undeveloped because conventional petroleum always hovered about $2 below the projected price of shale. Capital development costs have inflated almost as fast as OPEC prices. In the 1960s, when crude was selling for $2 a bbl., estimates were that oil from rock could be produced for $4 a bbl. Now, with world prices going up almost daily beyond the $23.50 OPEC level, shale oil may be produced for $30. But spurred by the ever higher price of crude, a group of energy entrepreneurs aim toward turning out more than 200,000 bbl. of shale...
...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...
...second, more radical method involves cooking the shale underground. Occidental, which has pioneered this process, plans to dig at 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...