Geoscience Reference
In-Depth Information
Overlapping Circle Shooting.
This was an attempt to
replace conventional straight
line shooting, removing the
need to stop shooting while
the boat turned
Spiral Shooting.
Used around circularly
symmetric bodies
such as salt domes
Fig. 2.5
Early non-standard 3-D marine acquisition techniques designed for efficient operations.
100 m
50 m
25 m
Fig. 2.6
The basics of multi-source, multi-streamer acquisition. As the boat sails along, the blue
and the red gun array fire alternately. When the red guns fire, the four red subsurface lines are
acquired. When the blue guns fire, the blue subsurface lines are recorded. The configuration shown
gives eight subsurface lines per sail-line of the boat, 25 m apart from each other.
and modern steerable cables may make this more common in the future. The separa-
tion between traces recorded along a line is controlled by the receiver spacing and is
usually between 6.25 and 12.5 m. As with the original marine survey design
(fig. 2.4)
,
a number of lines are shot together with the boat travelling in one direction, followed
by a similar section with the boat travelling in the opposite direction. Occasionally, the
