|Titre||Old marine seismic and new satellite radar data: Petroleum exploration of north west Labrador Sea, Canada|
|Auteur||Jauer, C D; Budkewitsch, P|
|Source||Marine and Petroleum Geology vol. 27, issue 7, 2010 p. 1379-1394, https://doi.org/10.1016/j.marpetgeo.2010.03.003|
|Séries alt.||Secteur des sciences de la Terre, Contribution externe 20090282|
|Document||publication en série|
|Media||papier; en ligne; numérique|
|Province||Région extracotière du nord|
|Lat/Long OENS||-64.0000 -56.0000 64.0000 56.0000|
|Sujets||hydrocarbures; pétrole; exploration pétrolière; topographie du fond océanique; topographie du fond océanique; levés géophysiques; levés magnétiques; levés gravimétriques; levés de reflexion sismiques;
suintements d'huile; télédétection; Bassin de Saglek ; combustibles fossiles; géophysique; stratigraphie|
|Illustrations||location maps; stratigraphic columns|
|Programme||GEM : La géocartographie de l'énergie et des minéraux|
|Programme||Sécurité de l'approvisionnement énergétique du
|Résumé||(disponible en anglais seulement)|
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 plays.