English abstract
Seismic data in south Oman suffers from high contamination of seismic multiple
compared to north Oman. Seimic multiples often mask the primary reflections, leading to
ambiguities in the geological interpretation and reducing the quality of seismic images.
Seismic multiple attenuation is a crucial step in seismic data processing, aimed at
enhancing the interpretability and reliability of subsurface imaging. Pre/Post-stack
seismic multiple attenuation techniques play a substantial role in mitigating the impact of
seismic multiples.
In south Oman, due to the sequence of fast and slow velocity at very shallow sections
which results in strong contrast in acoustic impedance yield certain types of multiple
contamination that mask the primary reflections at Haush level (the target formation),
where sediments are characterized by relatively low reflectivity, and lower velocities in
comparison with the overburden sediments. The application of the classic de-multiple
techniques such as predictive de-convolution methods and radon-based methods did not
satisfy the result due to the structural complexity at the target in this area. Also because of
the nature of the multiple and the dip discrimination between multiples and primaries is
very minimal.
With acquiring well-sampled seismic data with broadband sweep had to get better demultiple flow which can work better in reducing the multiple contamination from the data
that will result in producing high quality image of the subsurface. That could be achieved
by comparing both pre and post-stack approaches, using both data-driven techniques and
dip-filtering techniques.
The results demonstrate the cumulative effect of all steps (pre-stack and post-stack) in demultiple flow showing the removal of a significant amount of multiple energy. This
resulted in a more geologically meaningful image at the Haushi level in comparison to
previous processing results which help in the interpretation of subsurface structures such
as anticline, syncline, and dip closure by enhancing the resolution of seismic images. The new imaging helps reduce the risk of planning future wells in the region.
