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Venezuela are estimated at 250 billion barrels, equivalent to the
total reserves of Saudi Arabia.
Most oil shales are fine-grained sedimentary rocks
containing relatively large amounts of organic matter from which
significant amounts of shale oil and combustible gas can be
extracted by destructive distillation. One of the largest known
locations is the oil shale locked in the 40.000 km2 (16000 sq-mile)
Green River Formation in Colorado, Utah, and Wyoming.
Oil shale differs from coal whereby the organic matter in
shales has a higher atomic Hydrogen to Carbon ratio. Coal also has
an organic to inorganic matter ratio of more than 4,75 to 5 while as
oil shales have a higher content of sedimentary rock. Sources
estimate the world reserves of Oil Shales at more than 2,5 trillion
barrels.
Oil shales are thought to form when algae and sediment
deposit in lakes, lagoons and swamps where an anaerobic (oxygen
free) environment prevent the breakdown of organic matter, thus
allowing it to accumulate in thick layers. That is later covered with
overlying rock to be baked under high temperature and pressure.
However heat and pressure was lower than in oil and gas
reservoirs. The shale can be strip mined and processed with
distillation. Extraction with fracturing and heating is still relatively
unproven. Companies are experimenting with direct electrical
heating rather than e.g. steam injection. Extraction cost is currently
around 25-30 USD per barrel [9].

Coal, Coal Gasification and Liquefaction
Coal is similar in origin to oil shales but typically formed
from anaerobic decay of peat swamps relatively free from
nonorganic sediment deposits, reformed by heat and pressure. To
form a 1 meter thick coal layer, as much as 30 meters of peat was
originally required. Coal can vary from relatively pure carbon to
carbon soaked with hydrocarbons, sulfur etc.
It has been clear for decades that synthetic oil could be
created from coal. Coal gasification will transform coal into e.g.
methane. Liquefaction such as the Fischer- Tropsch process will

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