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Figure 2.11:
Drilling expeditions
and results, Ulleung Basin.
Scientific drilling expeditions
evaluated gas hydrates in the
Ulleung basin off the eastern coast
of South Korea in 2007 and in
2010. The drilling confirmed that
the basin contains a wide array
of gas hydrate occurrence types,
including a multitude of gas-
hydrate-bearing “gas chimneys”.
Above: Location of Ulleung
basin Right: Geophysical data
showing typical Ulleung basin gas
chimneys (vertical features with
anomalous physical properties)
(with permission from Ryu
et al.
,
2009). Drilling has confirmed high
concentrations of gas hydrates in
the centres of these chimneys.
Ulleung
basin
Shot-point:
(c)
500 m
E
W
“Blanking zone” with pull-up
structure
Shot-point:
5600 5700 5800
2.7
2.8
2.9
3.0
3.1
Depth in TWT (s)
E
W
(b)
1000 m
o
80 C/km
o
100 C/km
o
140 C/km
2.7
2.8
2.9
3900
3800
3700
3600
3500
3400
4000
Shot-point:
3.0
3.1
3.2
5800
5750
5700
Interval velocity (m/s)
(a)
Depth in TWT (s)