Shallow-Hazards and Deep-Water Deposition Systems Investigation Using Reprocessed High-Resolution Seismic Measurements in the Angoche Basin, Mozambique

A 3D multi-measurement seismic survey of the Angoche basin, Mozambique has been reprocessed from the original exploration-scale seismic to produce interpolated, higher-resolution data. This reprocessing has delivered a seismic image that is reliable enough for identification of hazards, attribute analysis and for inversion work. Deep water regimes, such as the Angoche Basin, give rise to specific hazards in a costly and geomechanically challenging environment. For example, we see a larger frequency in deep-water systems of shallow water flows and escape features that are expressed through pockmarks seen at the Intra-Eocene horizon. The extent of these features is much greater than previously known from the onshore processing (OSP) image. There is also much evidence of slope failure and their associated mass transport complexes (MTCs) in Angoche, which are critical to identify as these areas present risk when drilled. Seismic attributes are extracted from the top surface and basal shear surface interpretations to provide a greater understanding of the heterogeneity within the MTCs using the high-resolution data. This new method of providing an interpreted high-resolution survey over a large area provides an earlier indication of hazards giving more time and a greater chance of mitigating against drilling losses.