Only a few specific international
examples of shallow, basin margin gas have definitely been identified.
Documented accumulations of shallow biogenic gas (Leads:
Figure 4) are a good place to start. Locations 1 (offshore Gulf of
Mexico) and 2 (Cook Inlet, Alaska) are domestic, but could qualify as
the margins of one-sided basins. The remaining numbered locations
are international shallow biogenic gas accumulations, but may not all
be strictly associated with specific basin margins.
The northern part of the West Siberian Basin (Location 3) has a huge gas
accumulation that was originally thought to be biogenic. Subsequent studies
(Littke and others, 1999) have suggested that there is also a thermogenic
component and have demonstrated that a dynamic ground water flow system
is important. Depths may be slightly greater than the basin margin accumulations
in the US, but the northern part of the West Siberian Basin does qualify
as an international example of basin margin gas.
Other important biogenic gas accumulations include:
4. Carpathian Foredeep, Poland
5. Appennine Foredeep, Italy
6. Quaidum Basin, China
7. brine gas, Japan
In an international perspective, shallow basin margin gas accumulations
are particularly important energy resources for emerging and developing
countries. In addition, these are important energy reserves for developed
and industrialized countries that are attempting to diversify their energy
base. Most occurrences are shallow and consequently relatively
inexpensive to exploit. Widely-separated sweet spots can be used for pollution-free
local consumption--such as distributed
electrical generation in small power plants--until an infrastructure evolves.
Identification of basin margin shallow gas accumulations is therefore
an important job. And, you can help by submitting examples, both international