Angola 3D Reimaging Survey

Improve presalt imaging with reprocessed 3D data

WesternGeco in association with Sociedade Nacional de Combustíveis de Angola, E.P. (Sonangol E.P.) has recently completed a depth reimaging project consisting of 7,922 km² of 3D surveys in the Lower Congo Basin covering Blocks 46–48.

Survey map of Angola depth imaging project.

Reprocessed seismic image for Angola 3D.

Depth reimaged 3D data of the ultradeep Lower Congo Basin offshore Angola shows significant improvement in the imaging of salt geometry and subsalt and postsalt stratigraphy. Image courtesy of Sonangol E.P.

The project, which included the reprocessing of 3D data by applying advanced processing algorithms such as 3D GSMP general surface multiple prediction and anisotropic Kirchhoff prestack depth migration (PSDM), in addition to producing inversion ready gathers for AVO analysis, has revealed valuable subsurface insights. The reprocessed 3D data has significantly improved the imaging of presalt sediments and interpretation of basement architecture of the area.

Key highlights

3D GSMP general surface multiple prediction
3D anisotropic Kirchhoff prestack depth migration (PSDM)
AVO and inversion ready gathers

This image shows a root mean square (RMS) amplitude extraction of the Miocene reservoir in Blocks 46–48. Reprocessed data reveals the tertiary reservoir sands under the salt body have potential to form subsalt traps—providing valuable insights to support prospectivity assessments. Image courtesy of Sonangol E.P.