Schlumberger

Technical Paper: Wide Azimuth 3D 4C OBCA Key Breakthrough to Lead to the Development of Hild Field

Society: EAGE
Paper Number: C009
Presentation Date: 2007
 

Abstract

Seismic imaging is a major challenge for some complex fields in the North Sea. That is the case for the Hild Brent field discovery (Total E & P Norge operator) not yet developed due to inconsistent dynamic data and poor seismic image resulting from a seismic obscured area created by gas dismigration, strong energy multiples and a highly faulted reservoir.

Conventional 3D streamer data, despite several reprocessing did not allow reliable mapping of the reservoir geometry.

Total decided to acquire in 2003 a multi-azimuth 3D streamer survey, following positive experiences in the nearby UK fields (Dunbar/Alwyn) and a successful example on Varg field (Hegna and Gaus, 2003). The combined PSDM processing provided a significant improvement, however it was not considered as good enough to properly assess the main uncertainties related to the drilling of development wells.

As demonstrated on a similar OBC survey (Boelle et al. 2006), a high density wide-azimuth OBC geometry was considered as the most efficient solution and a 3D 4C OBC survey was acquired in 2005.

In this paper on Hild, we present the preliminary results and analysis based on fast track PSDM which proved the great potential of high density wide azimuth OBC 3D for imaging challenging targets. 

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