Technical Content

Images from Kirchhoff migration can suffer from uneven illumination and contamination by migration artefacts. One of the issues is that migration is not a true inverse operation – it is based on the adjoint of the forward modelling operator. In contrast, least squares migration ...

For long in seismic imaging, velocity model building and depth migration/inversion have produced information on the subsurface velocity model with no overlap in terms of resolved vertical wavelengths. The not covered wavelengths, among which the famous mid frequency gap, had then to be recovered ...

Assessing the uncertainty on the structural information contained in seismic images is critical for risk analysis in reservoir delineation, reserve estimation, and well planning. We propose here an original approach aiming at assessing structural uncertainties associated to ray based tomography. While it has similarities ...

3500 km2 of marine data from West of Shetlands have been reprocessed using latest processing technologies available (including deghosting). This case study demonstrates the benefit to re-process conventionnal data (acquired in the 90's) to get a broadband result (better definition, larger spectrum).

We propose a laterally constrained surface wave inversion to obtain a reliable near-surface shear-wave velocity field from Rayleigh wave measurements. This workflow is targeted at dense 3D broadband Wide-Azimuth land surveys, aiming to obtain reliable and realistic lateral shear-wave velocity variations pertinent with regard ...

A broadband Wide-Azimuth Towed-Streamer (WATS) survey was acquired in a shallow water region of offshore China for the purpose of resolving strike direction narrow-azimuth acquisition shortcomings. However, the current WATS acquisition is much sparser than WATS surveys in deep water environments. The challenges of ...

This paper describes a successful reservoir characterization workflow where geostatistical inversion was first carried out to characterize caves and vugs, and then azimuthal inversion was used to obtain fractures strike and density. It improves the precision of reservoir prediction, and effectively characterizes the distribution ...

We present a method to estimate and correct the phase of broadband seismic data in the low-frequency range using the tomography velocity model as an analogy for subsurface geology. The high-resolution velocity model is obtained from travel-time tomography and therefore has minimal influence from ...

In recent years there has been tremendous progress in the resolution and accuracy that can be obtained in seismic images. Several techniques are now available to achieve a high-definition final image. In the Cap-Boujdour dataset from offshore Morocco, the imaging is challenging due to ...