Petroleum Potential of Banks Island Segment, Canadian Arctic Passive Margin: Results from a New Regional Deep-Seismic Survey

Naresh Kumar, James Helwig, Pete Emmet, and Menno G. Dinkelman
ISS - GX Technology, ION Geophysical, Houston, TX.

The Banks Island segment of the Canadian Arctic Passive Margin (CAPM) covers approx. 70,000 sq km (27,000 sq mi), about the same size as the adjacent offshore Mackenzie Delta. The latter has been the primary focus of exploration since the 1970s with almost fifty identified oil and gas accumulations testifying the presence of and active petroleum system. The Banks Island margin however remains essentially untested.

Since 2006 ION Geophysical (GX Technology) has acquired more than 4000 km of 2D long-offset reconnaissance seismic data in the area as part of a larger Canadian Beaufort program (16,269 km). The seismic lines are located parallel and perpendicular to the Banks Island margin and in the Amundsen Gulf to the south. Cognizant of deep-water potential the lines extend as far as possible offshore as permitted by ice conditions and environmental considerations. The acquisition parameters have been designed to image down to the base of the crust with a 9-km long cable, 18-second recording, and final depth processing (PSDM) to 40 km. The seismic data are interpreted together with collected gravity-magnetic data to regionally map the ocean-continent boundary and the top of MOHO discontinuity, and tied to existing well data wherever possible to identify the major stratigraphic sequences.

Seismic interpretation identifies large structures and a thick Meso-Cenozoic passive margin sedimentary prism underlying the Banks Island margin. The sedimentary wedge is 8-10 km thick at the shelf edge and upper slope, and it overlies reflectors under the shelf, inferred to correlate with Paleozoic reflectors drilled by exploratory wells up dip on Banks Island and farther south under the Tuk Peninsula. Major structures include normal faults and some associated rollover anticlines on the middle and lower slope. Strike lines parallel to the slope show a complex of Oligocene/ Miocene channels, slumps, and interchannel facies, generally associated with slope deposits. Well calibration provides long-distance ties of major seismic horizons with the clastic Mesozoic-Tertiary reservoir and source intervals of the Mackenzie Delta.

The new seismic data confirm the large volume of the CAPM sedimentary prism, illuminate the architecture of the basin, and imply a significant potential petroleum province. The geology of the margin has all the components of the proven Beaufort Mackenzie basin along strike to the southwest, i.e. reservoir, source, seal, traps and timely migration.

AAPG Search and Discover Article #90096©2009 AAPG 3-P Arctic Conference and Exhibition, Moscow, Russia