Improving the imaging of pre-Messinian in the Eastern Mediterranean Sea - A case study using FWI

Abstract

Summary There has been an increase in interest for imaging beneath complex Messinian layers after large sub-Messinian discoveries in the Eastern Mediterranean Sea. There are several challenges for accurately imaging the pre- Messinian, including correctly illuminate the sub-salt section. This involves both optimizing acquisition parameters and building accurate geological models. The east Mediterranean is sparsely populated with multi - azimuth surveys; most are narrow azimuth. A lack of data diversity can degrade the imaging of sub-salt zones even when using accurate velocity models. Illumination issues in the east Mediterranean are primarily caused by a complex interaction of shales and salt. The Messinian layer is not always homogeneous and can be mixture of salt and clastics, which makes model building challenging in this region. We focus on a block of east Mediterranean Sea, using multi-sensor triple-source seismic data. Optimal velocity model building for depth imaging involves the application of complementary imaging technologies to mitigate assumptions in any single process. Using this strategy, we demonstrate a solution for the complex post-Messinian, carbonate, and Messinian layers, in order to improve the Pre-Messinian imaging and reduce uncertainty in the seismic amplitudes.