A Simple Seismic
Forward-Modelling
and Processing
Study of the Effects of Multiples on Interpretation-Gulf of Suez,
Egypt
By
Mostafa Kamel1, Mohamed Maged1, Maged Fahim1, Donald Easley2, Norm Allegar3, Jasper Peijs4
(1) Gupco, Cairo, Egypt (2) Gupco/bp, Cairo, Egypt (3) BP Egypt, Cairo, Egypt (4) BP, Houston, TX
Multiple contamination has long been recognized as a major obstacle to
correct seismic interpretation in the Gulf of Suez (Egypt). By using simple
modeling and processing
techniques and integration of seismic and well
information, we are able to determine some of the challenges facing seismic
interpreters. For example, we created a simple model of horizontal multiple
generators overlying a deeper faulted structure. By comparison of modeled and
actual data before and after
processing
, we can see many examples of the
potential pitfalls to interpretation, such as: false seismic stratigraphic
indicators, false structural lineaments and obscured hanging wall and footwall
correlations. We also demonstrate the power of integration of geological
information (dipmeter, model parameterization and depositional inferences) and
processing
techniques (SRME,
dip
-filtering, auto-correlation analysis and
iterated decon) to separate reality from artifacts.
A simple dip
discrimination map shows a small percentage of the multiples in
the Gulf of Suez are amenable to
dip
filtering techniques, because in many areas
the main multiples are potentially parallel to the primaries and the deep data
is concentrated in a low frequency band. This observation indicates that much of
the present exploration opportunities are still obscured by hard to remove
multiple energy; therefore, understanding of the artifacts through modelling
work and direct observation of the data can provide a list of pitfalls and
guidelines (as discussed) to help reduce seismic interpretation risk as well as
help guide interpretational
processing
. This also points to the future hope for
unveiling untapped resources beneath the blanket of multiples.