Oil and gas production handbook An introduction to oil ... - ABB Group

9 Unconventional and conventional
resources and environmental effects
About 81.1% of the world’s primary energy consumption in 2012 was fossil
fuels; 27.3% was coal, oil production was 32.4% or about 4.01 billion tons,
and 21.4% was gas, with 3,39 trillion scm or 3.01 billion tons oil equivalent
(TOE). Thus, total oil and gas production was 6.4 billion TOE, which is about
128.5 million barrels of oil equivalent per day (IEA 2012).
Proven reserves are estimated at 201 billion TOE of oil and 6707 tcf of gas
(180 trillion scm, 160 billion TOE) for a total of 361 billion TOE (converted
from estimates by US Department of Energy, 2012), indicating that proven
reserves will last for about 56 years.
9.1 Unconventional sources of oil and gas
The reservoirs described earlier are called conventional sources of oil and
gas. As demand increases, prices soar and new conventional resources
become economically viable. At the same time, production of oil and gas
from unconventional sources becomes more attractive. These
unconventional sources include very heavy crudes, oil sands, oil shale, gas
and synthetic crude from coal, coal bed methane, methane hydrates and
biofuels. At the same time, improved oil recovery (IOR) can improve the
percentage of the existing reservoirs that can be economically extracted.
These effects are illustrated in principle in the following figure.
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