Energiforsyning i Arktis – hvilken vej vælger Grønland? - Artek ...

a) b)
Figure 6: Gas hydrates in different shapes from the Hydrate Ridge, Oregon in 2000 (TECFLUX,
IFM-GEOMAR).
2. Potential Energy Source
Over the last decades, many countries have
become very interested in exploiting gas
hydrates as a potential energy source. This
has been of particular importance for
countries like Japan and India who do not
have direct access to other fossil fuel
sources.
One argument for using gas hydrates as an
energy source is the enormous amount of
methane that is globally stored in gas
hydrates. Most recent calculations predict
that about 10 x 10 15 m 3 to 40 x 10 15 m 3
methane occur in gas hydrate deposits
(Kvenvolden, 1999). Alone in the Arctic
Basin more than 1.1 x 10 15 m 3 methane can
be found (Kvenvolden & Grantz, 1990).
However, it should be mentioned that these
numbers are rough estimations that are
based on limited data. Besides the large
amount of methane that is globally stored
(Collett & Kuuskraa, 1998), other
advantages are that the energy density of
gas hydrates is 2-5 times larger than for
conventional natural gas (MacDonald, 1990)
and that they appear at shallow sediment
depths within 2,000 m of the surface
(Kvenvolden, 1999) and should thus be
accessible for exploration.
Although gas hydrates seem to be an
important energy source in the future, a
number of negative factors are responsible
for the limited interest in the development
of exploration technologies so far. One
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factor is the low permeability in the
sediments where gas hydrates occur, which
makes the access to the methane in the gas
hydrates very difficult, at least with
exploration techniques commonly used for
methane or oil production. Without
permeability only small accumulations of gas
can be found and moreover, the
accumulated gas cannot move into
production wells fast enough. In
consequence, the methane cannot be
produced by drilling (Levorsen, 1967) and
new technologies need to be invented.
Moreover, the significant gas hydrate
deposits are far away from the existing
conventional gas fields and thus, new
expensive infrastructure needs to be built.
Due to all these complications and the fact
that alternative resources (i.e., oil and
conventional gas) are still available, the
development of gas hydrate exploration
techniques is only slowly advancing. So far,
no field study has been successful,
including, for example, the Messoyakha gas
field project in Western Siberia (Makogon,
1997, Collett, 1993).
However, a variety of new gas hydrate
research programs in different parts of the
world are currently underway. Japan and
India, for example, have started to
implement large-scale field studies (Collett
& Kuuskraa, 1998), and the USA has
initiated an intense program in the US Gulf
of Mexico (DOE Gulf of Mexico Joint Industry
Project, 2009). Moreover, the German IFM-