AAPG ANNUAL CONFERENCE AND EXHIBITION
Making the Next Giant Leap in Geosciences
April 10-13, 2011, Houston, Texas, USA
The Acquisition of Deep, Long Offset Seismic Data Provides New Information on the Play Fairways on the NE Greenland Margin
(1) GeoArctic Ltd, Calgary, AB, Canada.
(2) ION Geophysical - GX Technology, Houston, TX.
Deep long-offset seismic data were acquired on the NE Greenland Shelf in 2009 and 2010 and a third phase, which is primarily an infill grid, is planned for 2011. The current Phase I data extend north of the Jan Mayen Fracture Zone to 81.5° N across the Hovgaard Fracture Zone. The Phase I survey covers the Danmarkshavn Basin, the Thetis Basin, and the Northeast Greenland Volcanic Province which are estimated to contain over 31 BBOE by the USGS.
Earlier attempts to acquire seismic data in the area have been hampered by heavy ice coverage. This was overcome by employing a proprietary streamer and deployment technology to acquire data below the pack ice. In addition to this an icebreaker was used to clear first-year ice for the primary acquisition vessel, allowing the seismic program to remain focused on geologic targets.
Pre-stack depth migrated (PSDM) seismic lines were used for the interpretation which was tested iteratively against gravity and magnetic modeling. The seismic data also images intra- and sub-basalt reflectors in the volcanic province and on the marginal high where seaward dipping reflectors are interpreted.
The data show a thick sedimentary sequence in the southern part of the Danmarkshavn and Thetis Basins which is at least 9 km thick. Both basins are interpreted to include a thick Mesozoic section. Older Palaeozoic sediments are also thought to be present in the Danmarkshavn Basin and subcrop along the Danmarkshavn Ridge which forms a prominent structural high separating the two basins. Extensive syn-rift faulting is interpreted along the eastern and western margins of the Danmarkshavn Ridge and large scale folding and doming have affected the area since break-up, leading to the development of potentially large and variable hydrocarbon traps, such as 4-way dip closures and combination rifted fault blocks.
The new seismic data has resulted in the identification of multiple play types and play fairways in the area, and numerous structural leads have been mapped. Based on regional basin analogs recent interpretations suggest that rich oil-prone Jurassic source rocks are present over much of the area. These observations, together with comparisons with the conjugate Mid-Norway margin, reinforce previous interpretations that the area has excellent hydrocarbon potential.