Page 50 - Introduction to Petroleum Engineering

34 THE FUTURE OF ENERGY
TABLE 2.2 Global Estimate of Technically Recoverable Reserves of Unconventional
Gas Trillion Standard Cubic Feet
Source Coal Gas Tight Gas Shale Gas Total
Holditch (2013) 1453 43 551 12 637 57 641
McGlade et al. (2013) 1384 1914 6823 10 121

other parts of the world. Although difficult to produce, the volume of hydrocarbon in
tar sands has stimulated efforts to develop production techniques.
The hydrocarbon in tar sands can be extracted by mining when they are close
enough to the surface. Near-surface tar sands have been found in many locations
around the world. In locations where oil shale and tar sands are too deep to mine, it
is necessary to increase the mobility of the hydrocarbon.
An increase in permeability or a decrease in viscosity can increase mobility.
Increasing the temperature of high API gravity oil, tar, or asphalt can signifi-
cantly reduce viscosity. If there is enough permeability to allow injection,
steam or hot water can be used to increase formation temperature and reduce
hydrocarbon viscosity. In many cases, however, permeability is too low to
allow significant injection of a heated fluid. An alternative to fluid injection is
electromagnetic heating. Radio frequency heating has been used in Canada,
and electromagnetic heating techniques are being developed for other parts of
the world.

2.4 GLOBAL DISTRIBUTION OF OIL AND GAS RESERVES

The global distribution of oil and gas is illustrated by presenting the size of a nation’s
reserves. Table 2.3 lists 15 countries with the largest proved oil reserves and 15 coun-
tries with the largest proved gas reserves. National reserves are found by summing
the reserves for all of the reservoirs in the nation.
Table 2.4 shows the regional distribution of oil and natural gas reserves. It is
notable that the Middle East is at the top of both lists, and Europe is at the bottom
of both lists. Political instability in the Middle East, which is home to many oil and
gas exporting nations, has raised concerns about the stability of the supply. The
lack of oil and natural gas reserves means that Europeans cannot rely on oil and
natural gas as primary energy sources. Concerns about the security of their energy
supply and the impact of fossil fuel combustion on the environment have helped
motivate the European Union to become a leader in the development and installa-
tion of renewable energy facilities such as wind farms and solar plants. France has
adopted nuclear fission energy as its primary energy source for electricity genera-
tion and has enough installed nuclear fission capacity to export electricity to other
European nations.