GEOSCAN, résultats de la recherche


TitreThe crucial importance of vitrinite reflectance data for basin understanding: Gulf of St. Lawrence, Canada
AuteurAvery, M; Wielens, H
SourceAdvances in organic petrology and organic geochemistry; Annual Meeting of the Society for Organic Petrology - Abstracts and Program (2009), 2009 p. 44
Séries alt.Secteur des sciences de la Terre, Contribution externe 20090213
RéunionJoint 61st ICCP/ 26th TSOP Meeting; Gramado; BR; Septembre 19-26, 2009
Documentpublication en série
ProvinceRégion extracotière de l'est
Lat/Long OENS-63.5000 -61.0000 48.0000 46.0000
Sujetsréflectance de la vitrinite; vitrinite; dépôts organiques; maturité organique; roches sédimentaires; évaporites; analyse du bassin; combustibles fossiles; géologie marine; Paléozoïque; Carbonifère; Dévonien
ProgrammeGEM : La géocartographie de l'énergie et des minéraux
Résumé(disponible en anglais seulement)
The Gulf of St. Lawrence in eastern Canada is underlain by a Paleozoic Basin, which saw sporadic exploration activity from 1965 to 1980, without commercial success. Significant gas was discovered in the East Point E-49 well DST.
A re-investigation was started by the Geological Survey of Canada, Atlantic. Lack of modern seismic data did not allow for a more detailed study than 1D modelling of the wells. Although well temperature data indicate present heat flow, they say nothing about the heat flow in the basin over its history. And, heat flow is the most sensitive factor in a petroleum system. The vitrinite reflectance data are the only handle available for this, and changed original ideas about the basin's history, such as rifting influences to more local events such as volcanics.
These results of 1D modelling show, based on the vitrinite data, that there appears to be a dissimilar heat-flow history for all wells, ranging from 60 to 95 mW/m2 at 151 Ma decreasing to 44 mW/m2 now. That heat-flow includes a possible volcanic event at 151 Ma near some wells but not others. Deep burial and later erosion of up to 2800 m defined the thermal maturity pattern. Fission track data confirm this amount.
The vitrinite data also show that some parts of this basin are still in the oil generation window, while others are over-mature.