|Title||Old marine seismic and new satellite radar data: Petroleum exploration of north west Labrador Sea, Canada|
|Author||Jauer, C D;
|Source||Marine and Petroleum Geology vol. 27, issue 7, 2010 p. 1379-1394, https://doi.org/10.1016/j.marpetgeo.2010.03.003|
|Alt Series||Earth Sciences Sector, Contribution Series 20090282|
|Media||paper; on-line; digital|
|Province||Northern offshore region|
|Lat/Long WENS||-64.0000 -56.0000 64.0000 56.0000|
|Subjects||fossil fuels; geophysics; stratigraphy; hydrocarbons; petroleum; petroleum exploration; seabottom topography; seafloor topography; geophysical surveys; magnetic surveys; gravity surveys; seismic
reflection surveys; oil seeps; remote sensing; Saglek Basin; Radarsat; SAR|
|Illustrations||location maps; stratigraphic columns|
for Energy and Minerals|
|Program||Secure Canadian Energy Supply|
|Abstract||This paper presents some new concepts in the petroleum systems of the northern Labrador and southern Baffin Island offshore region of eastern Canada. The focus of this work is the region of the Hekja
O-71 gas discovery of 1979 by Aquitaine, one of only five wells drilled between 1976 and 1980 within an area covering some 166,000 square kilometers within the Saglek Basin.|
This study emerged from a broad scale re-examination of the petroleum
potential of this area "from the crust up" using regional reflection, refraction and potential field data. An opportunity to use SAR (synthetic aperture radar) data from the RADARSAT-1 Earth observation satellite was taken to incorporate alternative
data sources to support this exploratory review and resource assessment.
Examination of the final map of interpreted slick-like features on the sea surface, revealed a close correlation of some of these occurrences to several bathymetric features
which have underlying seismic signatures similar to previously identified gas hydrate "pipes" or chimney anomalies as seen in data from offshore Nova Scotia and in the Irish Sea. Globally, many active marine hydrocarbon seeps appear on the seafloor
as "pockmarks"; in this case no seafloor depressions were seen on conventional multi channel 2-D seismic data associated with active seepage. Instead, very distinct mound-like structures are seen associated with seeps at two locations east of Hudson
Strait. The presence of significant cold water coral in close proximity to the active seepage sites may show a link between seafloor petroleum seepage and coral reef development similar to that observed offshore Norway.
Close examination of the
near surface seismic character led to the interpretation of what was originally seen as seismic noise in vintage data, as likely being fluid escape chimneys or gas pipes, along the eastern edge of the Hekja structural complex, where favourable
hydrocarbon trapping conditions are present.
No active seeps were seen there; this may be due to other factors, such as the nature of the fluids that are escaping or the possibility of self sealing activity by biological agents such as bacterial
matting with associated carbonate hard-ground formation.
One seep anomaly was noted relatively close to the major basaltic eruptive complex near the Gjoa G-37 well. This may be due to the presence of volcaniclastic- hosted hydrocarbons similar in
style to those recently discovered at the Rosebank field in Paleocene volcanics in the Faroe-Shetland Basin. The occurrence of an active seep in a volcanically-dominated terrain raises the potential for a radical shift in accepted types of petroleum
leads and where they may occur.
The presence of apparent oil seepage versus the past history of finding only gas-prone accumulations is a strong indicator that a second, oil-prone petroleum system exists in the Saglek Basin. The signs of active
petroleum systems as shown by oil seep anomalies with confirming seismic evidence of discrete sea floor structures in close proximity makes a compelling argument for re-examining these areas with an eye towards stratigraphic instead of structural