3D Seismic
for Exploration, an Integrated Process from Acquisition to
Interpretation
By
Naema Obaid Al-Zaabi1, Saleh A. Bin Sumaidaa1, Jean Francois Dervieux1, Abu Baker Al Jeelani1, Erik Bernardus Kleiss1, Mohamad Samir Al Nahhas1
(1) Abu Dhabi Company for Onshore Oil Operations (ADCO), Abu Dhabi, United Arab Emirates
The large four way closures have been found. The remaining traps require
high quality and densely sampled data
to properly explore, evaluate and risk
prospects. 3D
seismic
can be used cost effectively to derive useful information
for pure exploration.
This example shows 3D data
over an area dominated by large sand dunes
alternated with sabkha plains generating static problems, and with severe
surface and internal multiples. A careful acquisition design and processing
sequence and the involvement of an integrated team of geophysicists and
seismic
interpreters have lead to excellent results.
'Wide-line' or 'Sparse' 3D seismic
data
have been acquired with relatively
large source- and receiver line spacing, low sweep effort per source point but
with long offsets and still reasonable fold, as compared to field-development
3D's. Despite these economised parameters, the final result is very detailed.
Structural and stratigraphic features can be highlighted using attribute mapping
and 3D visualization tools.
Seismic
amplitudes relate to reservoir porosity and
are a valuable risking tool. The
data
allow a better geological understanding of
the area both in structure and stratigraphy. These good
data
provide a higher
degree of confidence and improve the risk evaluation associated with each of the
multiple exploration prospects.
These high quality data
are the result of working as an integrated team; a
case history showing the importance of such teamwork on optimizing all steps of
the geophysical process in a difficult terrain.