12. Imaging/Interpretation Frontiers

PGS MegaSurveys: Enhanced Regional Imaging of Hydrocarbon Provinces

Huw Edwards(1), Ken Davidson(1), Chris Loader(1), Shane Westlake(2) and Suvimol Maingarm(3)

(1) PGS Reservoir, UK. (2) PGS Reservoir, Perth. (3) PGS Reservoir, Singapore.

Abstract

In maturing hydrocarbon provinces such as the NW Shelf, Australia and the North Sea, Europe, most if not all of the large and more obvious structural closures have already been mapped and drilled. Finding the remaining smaller fields with subtle geophysical expression is a challenge and a thorough understanding of the geology is essential. To achieve this, the depositional systems and sub-surface structure must be analysed in a regional context as well as locally.

In general, exploration companies's regional models have been based on an amalgamation of 2D and 3D seismic data of varying vintages, orientation and quality. Thus, they are often incomplete and lack detail in the 2D data areas. To address this problem, PGS initiated the MegaSurvey Project, merging a number of 3D surveys into large, consistent 3D datasets. For the first time, the regional picture and prospect-size detail are both available from a single dataset.

Merging oil company and contractor non-exclusive 3D seismic data into single datasets has created the North Sea, Vulcan and Carnarvon basins MegaSurveys, covering an area of approximately 60,000 sq. km, 18,000 sq. km and 18,400 sq. km respectively.

The MegaSurvey seismic data and consistent horizon interpretation (tied to release well control) enables asset focused oil companies to concentrate on more detailed search of subtle traps, and to understand and develop remaining reserves. The PGS 3D MegaSurveys allow visualisation and analysis of the sub-surface on a scale and resolution that is greatly enhanced, providing detailed depositional and structural information over complete basins.

This paper will present examples of how MegaSurveys can be used to help unlock the remaining potential in maturing hydrocarbon provinces, with dramatic visualisations of the sub-surface within the North Sea Graben, the Vulcan and Carnarvon basins in Australia.

Last modified: Wed May 10 16:58:49 2006