Page 185 - Synthetic Fuels Handbook

FUELS FROM OIL SHALE 171

TABLE 6.1 Timeline of Oil Shale Projects in the United States (Continued)
1982 Oil demand falls and crude oil prices collapse
1982 Exxon Black Sunday: announces closure of Colony II due to cost and lower demand
1982 Shell continues in situ experiments at Red Pinnacle and laboratories through 1983
1985 Congress abolishes Synthetic Liquid Fuels Program after 40 years and $8 billion
1987 Shell purchases Ertl-Mahogany and Pacific tracts in Colorado
1987 Paraho reorganizes as New Paraho and begins production of SOMAT asphalt additive used in
test strips in five states
1990 Exxon sells Battlement Mesa for retirement community
1991 Occidental closes C-b tract project before first retort begins operation
1991 Unocal closes Long Ridge after 5 million barrels and 10 years for operational issues and losses
1991 LLNL plans $20 million experiment plant at Parachute; Congress halts test funds in 1993
1991 New paraho reports successful tests of SOMAT shale oil asphalt additive
1997 DOE cedes oil shale lands to DOI/BLM
1997 Shell tests in situ heating on Mahogany property; defers further work on economic basis
2000 BLM seeks public comment on management of oil shale lands
2000 Shell returns to Mahogany with expanded in situ heating technology research plan (ongoing)
2004 DOE Office of Naval Petroleum and Oil Shale Reserves initiates study of the strategic
significance of America’s oil shale resources

By 1982, however, technology advances and new discoveries of offshore oil resources
in the North Sea and elsewhere provided new and diverse sources for oil imports into the
United States, and dampened global energy prices. Global political shifts promised to open
previously restricted provinces to oil and gas exploration, and led economists and other
experts to predict a long future of relatively low and stable oil prices. Despite significant
investments by energy companies, numerous variations and advances in mining, restora-
tion, retorting, and in situ processes, the costs of oil shale production relative to foreseeable
oil prices made continuation of most commercial efforts impractical. During this time,
numerous projects that were initiated and then terminated, primarily due to economic infea-
sibility relative to expected world oil prices or project design issues.
Several projects failed for technical and design reasons. Federal research and develop-
ment, leasing, and other activities were significantly curtailed, and most commercial proj-
ects were abandoned. The collapse of world oil prices in 1984 seemed to seal the fate of oil
shale as a serious player in the nation’s energy strategy.
Oil shale is a complex and intimate mixture of organic and inorganic materials that vary
widely in composition and properties. In general terms, oil shale is a fine-grained sedimen-
tary rock that is rich in organic matter and yields oil when heated. Some oil shale is genuine
shale but others have been misclassified and are actually siltstones, impure limestone, or
even impure coal. Oil shale does not contain oil and only produces oil when it is heated
to about 500°C (932°F), when some of the organic material is transformed into a distillate
similar to crude oil.
There is no scientific definition of oil shale and the current definition is based on eco-
nomics. Generally, oil shale is a mixture of carbonaceous molecules dispersed in an inor-
ganic (mineral) matrix. It is called shale because it is found in a layered structure typical of
sedimentary rocks, but the mineral composition can vary from true aluminosilicate shale
to carbonate minerals. Thus, oil shale is a compact, laminated rock of sedimentary origin
that yields over 33 percent of ash and contains insoluble organic matter that yields oil when
distilled.
The amount of kerogen in the shale varies with depth, with the richer portions appearing
much darker. For example, in Colorado (U.S.), the richest layers are termed the Mahogany
Zone after the rich brown color.