Reprocessing for Shallow Hazard Studies, Barents Sea

GeoStreamer data from the Barents Sea is reprocessed using SWIM to provide excellent resolution at shallow depths and reliable AVO attributes.

GeoStreamer data, even if originally acquired for exploration purposes, can be reprocessed to generate high resolution images of the shallow subsurface and used for Shallow HAZard (SHAZ) assessments.  

SHAZ processing aims to produce high resolution images of the overburden by processing at a 2 or 3 ms sampling rate (2 or 3 m in depth) and on a dense image grid.  GeoStreamer data is the best input for such processing as it is characterized by high signal-to-noise and uncompromised receiver deghosting.

GeoStreamer PURE consists of four unified 3D datasets in northwest Europe and the Barents Sea exclusively using GeoStreamer 3D data. The data has been merged and reprocessed using advanced imaging workflows to create a premium product.

In the example below from the Barents Sea the GeoStreamer data has been reprocessed using Separated Wavefield Imaging (SWIM) for the first few hundred meters and then combined with conventional Kirchhoff Q-migration image deeper in the section.

SWIM effectively removes footprint issues in the shallows, which is a major drawback of conventional seismic surveys. The optimized tools and workflows allow full integrity processing at 2 ms in order to produce the highest possible resolution images.

The detection of shallow gas and the AVO characterization of the shallow reservoir are the obvious benefits in this SHAZ data example.

Depth slice showing dramatic improvement in resolution with SWIM imaging of the shallow hazards. The acquisition footprint is clearly obvious on the left hand side image and this obscures the resolution of the shallow gas. In comparison the SWIM depth slice shows the elimination of the footprint and excellent resolution of small details such as glacial striations and evidence of shallow gas (arrow).

 

Reprocessing using SWIM to improve resolution and AVO in the shallow part of the section revealing shallow gas hazards in the area (arrow).