Most oil shale exploration has been accomplished in the half century prior to 1970. Deposits are delineated, but detailed blocking-out of reserves remains to be done in optimum areas where development is proposed. Eighty percent of thick, rich oil shale is in Colorado, 15% in Utah, and 5% in Wyoming.

Oil-shale development appears likely to begin on federal lands in Colorado, and possibly in Utah, in accord with the program of the U.S. Department of the Interior. Utah is the only oil-shale state having sizable blocks of state lands in optimum areas. Development could begin on these if the question of state entitlement to additional federal lands is resolved promptly. Development of private lands in Colorado and Utah also appears likely. Wyoming lands--federal, state and private--have attracted little development interest. All development to date involves underground mining and above-ground retorting.

Oil-impregnated rock--sandstone and limestone--occurs in 22 states, but few deposits are known in detail. Important deposits are known in 13 states. A concerted mapping program places about 90-95% of the nation's mapped reserve in Utah in deposits totaling 20-25 billion bbl of oil in place.

Deposits in about 11 states have been used for paving and aggregate. None has been exploited as a source of oil, although varied experimental and pilot work has been conducted for this purpose in at least 9 states. Although mining, processing, and refining technology is known and highly developed, unfavorable economics have deterred development. In situ methods are largely in an experimental stage. In many deposits techniques used in primary or secondary recovery of conventional or heavy crude oils show promise. Experience in the Canadian Athabasca tar sands deposit is expected to strongly influence U.S. activity.

By 1975, small-scale production of shale oil should nearly be under way in western Colorado and possibly in Utah. From about 50,000 bbl/day of oil in 1976 this

End_Page 649------------------------------

should escalate to 800,000 to 1,300,000 bbl/day in 1985. Production of synthetic crude oil from oil-impregnated rock should develop in the decade 1975-1985. Both supplemental oil sources are certain to be important parts of the nation's pool of available energy from 1980 into the next century.

Unforeseen world events and political/economic decisions at high government levels can profoundly affect and alter these timetables.

End_of_Article - Last_Page 650------------