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Integrated Interpretation of Reflection Seismic, Potential Field and Petroleum Geology Data in the Hopedale Basin, Canadian Labrador Sea

Enachescu, Michael E.1; Lyatsky, Henry 2; Colton, Penny 3; Einarsson, Paul 3
1 Exploration, MGM Energy Corp., Calgary, AB, Canada.
2 Exploration, Lyatsky Geoscience Research & Consulting LTD., Calgary, AB, Canada.
3 Data Acquisition, Geophysical Service Incorporated, Calgary, AB, Canada.

During 2003-2008 new 2D reflection seismic lines were recorded simultaneously with magnetic and gravity profiles over the Hopedale Basin, offshore Labrador. Several gas discoveries totaling about 4.2 Tcf are located in this late Mesozoic basin formed during the separation of Greenland and Labrador. The main gas discoveries were surrounded by the 2008 Newfoundland and Labrador landsale parcels resulting in four very large, shallow water Exploration Licenses being awarded. In the next few years 3D seismic needs to be collected and after a 25 year break, renewed drilling will take place in the Hopedale Basin during the short offshore Labrador exploration season. These costly operations greatly benefit from the synergistic interpretation and mapping of all available geological and geophysical data to minimize exploration expenses, confirm exploration leads and determine the size and locations of 3D surveys.

The new 2D seismic data is processed to 8 seconds including pre-stack time migration to provide for: a) better imaging of the deeply seated basement structure on the shelf; b) improved resolution and continuity of the main seismic markers, some of which are associated to regional unconformities, and c) firming petroleum leads at the level of Bjarni and younger reservoir sandstones. The processed set of potential field profiles and maps include conditioned main potential fields, first and second order derivatives, gradients, upward continuations, reduction to pole, shadowgrams and several complex transforms.

It is important to note that several contentious interpretation issues remain related to the position, nature and properties of the basement and the thickness of overlying synrift volcanics, especially on the outer shelf and slope, were deep sedimentary basins are observed. Know to exist in the area, Paleozoic prerift carbonates form an additional reservoir that has been generally ignored because they are seismically difficult to detect. In these situations the gravity and magnetic data becomes essential in providing additional valuable information.

Several important regional seismic lines, all located in the Hopedale Basin and intersecting exploration wells or large undrilled features, are used concomitant with the most relevant potential field profiles and maps to further aid in the interpretation of the regional geology and to expand the petroleum potential of the Canadian Labrador shelf and slope.

 

AAPG Search and Discovery Article #90090©2009 AAPG Annual Convention and Exhibition, Denver, Colorado, June 7-10, 2009