Minerals Report - International Seabed Authority

Offshore oil supply growth is expected to come increasingly from
areas outside the North Sea and the Persian. “By 2005, five fields, two off
Brazil and one each in West African waters, the Gulf of Mexico and the
Norwegian Sea, are expected to move into the top 25, and several other
potential major producers off West Africa and in the deep-water Gulf of
Mexico could be approaching similar production levels in the next decade”
(IEA, 1996).
4.6.4 Resource potential of marine hydrocarbon deposits
According to the International Energy Agency (IEA, 1996), “worldwide
offshore oil production in 1995 is estimated to have been 21.3 million
barrels per day (mb/d) or just over 30% of total world supply of crude oil and
natural gas, representing an increase of 3.9 mb/d versus 1990.” The IEA also
consider current offshore reserves “to be of the order of 200 billion barrels or
about 20% of the world total. However, much of the undiscovered
economically recoverable resource base is believed to lie offshore.”
Much of the offshore hydrocarbon resource also lies within strata that
does not allow production due to excessive water depth and/or difficulties in
extraction. However, technological improvements in recovery efficiency and
greater access to deep-water areas are increasing the range of economically
recoverable resources offshore.
Thus the estimated proved reserves of oil world-wide at the beginning
of the 21st Century is about one trillion barrels. Of this amount, about 252
billion barrels (25 per cent) are estimated to lie in sub-sea environments.
Similarly, the total world-wide proved resources of natural gas is estimated as
about 4,000 trillion cubic feet, of which about 26 percent are estimated to be
sub-sea. However, these offshore resources may be as much as ten times
larger, in which case they will provide the majority of future hydrocarbon
production (IEA, 1996).
Here, we describe the offshore hydrocarbon resources that potentially
lay within the ELCS areas of the world. The term “resource” is used here to
include all the conventional hydrocarbons (oil and gas) that in areas where
conditions for hydrocarbon formation and accumulation are favourable. As
IINTERNATIONAL SEABED AUTHORITY 719