Geology of Terra Nova Oil Field, Grand Banks, Newfoundland

John D. Dwyer, Gerald W. Sullivan, James Park

Oil was discovered at the Petro-Canada et al Terra Nova K-08 well in May 1984. The well was drilled in the Jeanne d'Arc subbasin, 340 km east of St. John's, Newfoundland, and 35 km southeast of the giant Hibernia oil field. Follow-up wells provided log correlations and core data that have been used with a three-dimensional seismic survey to construct a geologic model. Mapping the field demonstrated a combination structural-stratigraphic trap.

The reservoir is within the lower part of the Jeanne d'Arc sequence (Upper Jurassic). This conglomeratic sandstone is interpreted as having been deposited in a nearshore to fluvial setting by basinward, northward progradation of fan-delta systems. The reservoir has a depositional limit updip to the south, and is overstepped and sealed by transgressive shales of the upper Jeanne d'Arc. Oil source is from the underlying Egret (Oxfordian-Kimmeridgian) argillaceous limestones.

The geologic model and seismic interpretation have been tested by appraisal drilling.

AAPG Search and Discovery Article #91043©1986 AAPG Annual Convention, Atlanta, Georgia, June 15-18, 1986.