Hydrocarbon loss from oil and gas fields of the Sverdrup Basin, Canadian Arctic Islands

Seventeen hydrocarbon fields have been discovered along a fairway which extends from Sabine Peninsula, Melville Island to western Ellef Ringnes Island in the western Sverdrup Basin. The fields are all on structural culminations which have associated faults and fractures. The oil and gas were sourced from Middle and Upper Triassic bituminous shales. The presence of water-bearing structural closures, in which reservoir units are sometimes oil stained, within this hydrocarbon fairway has led to the concept that considerable oil and gas have been lost due to upward migration along the fault and fracture zones on the structures. This hypothesis is strongly supported by the occurrence of oil and gas in stacked reservoirs ranging in age from Upper Triassic to Lower Cretaceous and separated from the source beds by up to 2000 m of vertical relief and by the presence of a thick residual oil zone in two oil and gas fields. This residual oil zone was likely formed due to the upward migration of the oil-water contact caused by the escape of gas from the structures.