Abstract:
The aim of this desertion is to evaluate the hydrocarbon potential evaluation of Penobscot area, Sable sub basin, Offshore Canada. Study Area is located between 44°05′00′′ W and -60°07′30′′ N near Sable Island, Halifax is the nearest city from Sable Island. For this purpose Structural interpretation, source rock maturity evaluation, trapping mechanism and migration path of hydrocarbon established. Inversion is carried out for Cretaceous and Jurassic reservoir characterization.
Geology of area is complex due to presence of salt (Agro Formation) of Late Triassic to Early Jurassic age. Sense of displacement of north- south fault gets inverted at the level of Jurassic and below. At recent and Cretaceous level it is down to south and at the level of Jurassic it is down to north, the movement of salt along the fault from the southern side invert the normal sense of displacement to reverse at Jurassic level, at the level of Early Cretaceous salt has impact on displacement of fault but it could not able to reverse it. There are two well lies within seismic cube that are B-41 and L-30. B-41 well drilled on classic four-way dip closure. L-30 drilled on roll over anticline bounded by E-W fault. Both well penetrated the Jurassic (Abenaki) formation. There were some shows in L-30 well, so dry hole analysis carried out for Cretaceous and Jurassic reservoir which reveals that source for Cretaceous reservoir is immature based on Vitrinite reflectance which is 0.59%, also model for tapping and migration of hydrocarbon for well L-30 proved that well was drilled at point where Cretaceous sands are Juxtaposed against sand so if the reservoir is mature it would migrate up dip to north. Source for the Jurassic reservoir is in early maturation stage.
For reservoir predication of the Jurassic carbonate, seismic inversion and carbonate facies model generated. Same algorithm is run for Cretaceous sand reservoir. In seismic inversion there is an ambiguity seen in transforming impedance values into Rock properties like porosity. At some point there is a sharp increase in Porosity and low impedance observed which gives good indication of reservoir but this picture is pseudo, arises from the presence of shale. Shale has excellent porosity and gives low impedance like reservoir rock. The task here is to separate those points of
