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7th Middle East Geosciences Conference and Exhibition
Manama, Bahrain
March 27-29, 2006
Multiples
: a Case History from the Middle East
PGS Technology, PGS Court, Halfway Green, Walton-on-Thames, KT12 1RS, United Kingdom, phone: +44-1932266418,
[email protected]
In this case study, examples are shown of the application of data-driven multiple removal techniques to land data sets from
the Middle East. Typically, these data are characterized by the presence of severe noise, high-
amplitude
free-surface
multiples
& internal reverberations, and weak primaries. This paper will shade lights on some of the practical aspects of
applying these data-driven multiple removal techniques. In particular, the pre-conditioning of data is discussed, as well as
how existing methodologies can be modified to subtract the predicted
multiples
from the data optimally while preserving
weak primaries. Also, the role of forward modelling and QC & QA, procedures are discussed. Prestack or poststack
modelling is used to identify the key internal boundaries that generate the
multiples
. By using reflectors present in the data,
predicted
multiples
are compared to the
multiples
present in the data to verify their contribution to the multiple problem.
Using this information, interbed multiple removal can be optimized to predict internal
multiples
effectively and efficiently.
Finally, the paper discusses how QC tools can be used in production processing to ensure that only
multiples
are removed
from the data while preserving the weak primaries.