Environmental Engineering Reference
In-Depth Information
barrels per year). At this rate of consumption existing reserves should last no more
than 41 years.
Such numbers refer to the reserves of the petroleum that are extracted with
present technologies (or “conventional” oil). There are much larger reserves of
“unconventional” oil (or very heavy oils) in sands in Alberta, Canada. Additionally,
offshore oil could extend the life of the present reserves by at least another few
decades.
There is an alternative theory about the formation of oil and gas deposits. Accord-
ing to it, oil is not a fossil fuel at all but was formed deep in the Earth's crust from
inorganic materials. The theory argues that the formation of oil deposits requires
the high pressures only found in the deep mantle and that the hydrocarbon con-
tents in sediments do not contain sufficient organic material to supply the enorm-
ous amounts of petroleum found in very large oil fields.
The notion of abiotic oil was proposed first in the 1950s and elaborated more
recently by Thomas Gold: hydrogen and carbon, under high temperature and pres-
sures found in the mantle during the formation of the Earth formed, hydrocarbon
molecules that have gradually leaked up to the Earth's surface through cracks in
rocks. Furthermore, the biomarkers found in oil were produced through the meta-
bolism of bacteria found in extreme environments similar to those in hydrothermal
vents and volcanic places where it was formerly believed that life was not possible.
Most geologists reject Gold's theory, which is considered controversial due to lack
of clear-cut experimental evidence.
Crude oil prices behave much as any other commodity, with wide price swings in
times of shortage or oversupply. The prices can also be influenced severely by the
action of cartel wars or political events.
Oil was very expensive early in its use (around US$70 per barrel) but declined
sharply owing to its abundance, and the price remained below US$10 per barrel
for almost one century. With the October 5, 1973, start of the Yom Kippur War,
fought between Israel and Syria and Egypt, OPEC—the Organization of the Petro-
leum Exporting Countries (whose members include Iran, Iraq, Kuwait, Saudi Ar-
abia, Venezuela, Qatar, Indonesia, Libya, United Arab Emirates, Algeria, and Ni-
