Print this pageReservoir Delineation Using High Resolution Seismic 
Data
in
the South China Sea
David L. J. Tsay
Conventional seismic data with the frequency bandwidth of 10-80 hz has been
playing an invaluable role in mapping favorable subsurface structure for initial
exploratory drilling. However, in order to characterize the reservoir properties
over the discovered field for reservoir delineation, the seismic data must have
the frequency components higher than 80 hz. This is particularly true when the
desirable reservoir properties to be delineated are the thickness and porosity
of several thin layers within the Miocene carbonate reservoir in the South China
Sea. In this paper, two methods of enhancing seismic resolution will be
discussed and illustrated with the examples of real data taken from the South
China Sea.
The first method of enhancing seismic resolution is to apply the technique of
spectral whitening to the original seismic data. The resulted data shows that
the frequency bandwidth is almost doubled from the original 10-80 hz to 10-140
hz. As a result, the thickness of each thin layer within Miocene carbonate
reservoir can be resolved at 7m instead of 12m from the original data.
The second method is to designed a new field parameter by using a shallower
towed depth of seismic energy source at 4m instead of 6m used previously.
Because of shallower towed depth, the first notch of source ghost becomes higher
and leads to higher resolution of acquired field data
with the frequency range
of 10-140 hz. Consequently, a thin bed of 7m within carbonate reservoir can be
resolved.
The success of enhancing seismic resolution has led to better reservoir delineation, drilling operation design and development plan.
AAPG Search and Discover Article #91019©1996 AAPG Convention and Exhibition 19-22 May 1996, San Diego, California