A Hydrocarbon Charge Model of the Hibernia Drainage Area,Jeanne d'Arc Basin,Offshore Newfoundland

An integration of map based and geological/geochemical modelling methodologies has enabled us to image the burial, subsidence, thermal and organic maturation histories of an area which, given its present and past structural geometry, drains into the Hibernia Oil Field. Our models indicate that the deeper parts of the Hibernia Drainage Area (HDA) contributed significant volumes of hydrocarbons, as early as 80–100 Ma, to the Hibernia structural culmination. The shallower portion of the HDA, such as the area vertically below pooled petroleum at Hibernia, has only been contributing hydrocarbons during the last 30–40 Ma. Translation of the modelled maturation history into volumetric estimates of generated, expelled and migrated oil within the area is accomplished assuming a 20% saturation threshold prior to hydrocarbon flow from the source to the reservoir/carrier system. Secondary Migration loss is estimated through assuming a reservoir/carrier-wide residual saturation of 2%. Our volume estimates suggest that the defined HDA was unable to provide sufficient charge volumes to fill the Hibernia structure and that additional charge must have been available from a drainage area to the north across the Nautilus fault. Extrapolation of HDA volumes throughout specifically defined play areas and the broader Jeanne d'Arc Basin suggests that, after accounting for secondary migration loss and assuming 30% recovery efficiency, some 2,015 10⁶m³ (12,650 Mmbbls) of oil remains to be discovered. Our models do not account for losses due to biodegradation processes. Although this is not thought to be significant within the HDA, it will reduce basin-wide resources estimates and requires further study.