PGS, Sonangol in Kwanza 3D survey offshore Angola

Norwegian seismic services provider PGS, in cooperation with Angolan state-owned oil company Sonangol, is acquiring a new survey over the shallow-water shelf area of the Kwanza Basin off Angola.

PGS said on Tuesday that the imaging of the new 3D GeoStreamer surveys would be conducted over Kwanza Basin open shelf blocks 6,7, and 8.

The Kwanza Shelf includes fields and discoveries with reservoirs in both the presalt and the post-salt. These blocks have been overlooked in recent exploration cycles with just five exploration wells drilled on the shelf since 1993.

The company added that the untapped hydrocarbon potential of the Kwanza Shelf was thought to be considerable and that the area was witnessing a resurgence in exploration interest. Kwanza could potentially hold more than 800 million barrels of oil equivalent.

This new multisensor 3D GeoStreamer survey, together with gravity and magnetic data, over the central part of the shelf will identify presalt and post-salt plays.

The acquisition configuration uses triple-source with 12 x 8,025-meter streamers operating in fan mode and multisensor GeoStreamer technology to provide clearer images with reliable attributes.

A modern prestack depth processing workflow has been tailored to the imaging challenges of subsalt stratigraphy within a shallow water setting.

The preprocessing will include targeted 3D shallow water demultiple, while the velocity model build will include full waveform inversion (FWI). Deliverables will include PSDM Kirchhoff stack, RTM PSDM, angle gathers, velocity models as well as gravity and magnetic data.