Seismic Data

Seismic data from the south of the Sultanate of Oman presents unique challenges due to complex short-period surface and internal multiples generated in the upper section. This technical article introduces an innovative demultiple workflow designed to tackle these issues in the pre-migration pre-stack domain. The method combines least-squares multiple imaging with a one-way wave-equation multiple prediction, producing accurate multiple models while preserving key primary events. This approach enabled high-definition imaging of reflectors like the Ghadir Manqil and enhanced geological interpretation of the Haushi interval, supporting more precise tomographic velocity updates.

Shallow water regions of the Gulf of Mexico hold promising petroleum prospects but pose imaging challenges due to complex overburden velocity in the Mesozoic section. Traditional sparse OBC surveys struggled to resolve these features. This technical article highlights a Time-lag Full-Waveform Inversion (TLFWI)-driven velocity model building (VMB) approach that significantly improved imaging of faulted sediment basins, allochthonous salt formations, and carbonate blocks. Combining TLFWI with FWI Imaging unveiled deep Mesozoic structures, enabling a clearer geological interpretation of the basin and unlocking new exploration potential.

While Land Full-Waveform Inversion (FWI) has been applied to seismic data in Oman, its use has typically been limited to low-frequency updates for migration. This technical article presents a breakthrough application of acoustic FWI up to 35 Hz, enabled by optimized data conditioning, initial model preparation, and velocity inversion. The resulting FWI Image, derived from the velocity model, delivers a superior view of the complex fault system, surpassing conventional imaging methods by leveraging the full wavefield and least-squares fitting across all frequencies.