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.