Chapter 36 Petroleum prospectivity of the Triassic–Jurassic succession of Sverdrup Basin, Canadian Arctic Archipelago

Abstract

Abstract The Sverdrup Basin of the Canadian Arctic Archipelago is an established petroliferous, rift/sag basin with 17 discovered oil and gas fields. Almost all the hydrocarbons occur in Triassic–Jurassic shallow marine sandstones and were sourced from Middle to Upper Triassic bituminous shales. The discovered fields occur on the culminations of Palaeogene structures. Three prospective areas for future discoveries in the Triassic–Jurassic succession include western Sverdrup, southeastern Sverdrup and the Fosheim Peninsula area. Most of the large structures in these prospective areas were mapped and tested in the initial round of hydrocarbon exploration. The largest potential play which has not been tested involves a stratigraphic component as part of the hydrocarbon trapping mechanism. Potential reservoir units are developed on the third-order sequence scale and 22 such sequences have been delineated in the Triassic–Jurassic succession. Most of them contain a progradational, shallow marine sandstone unit which is in part porous within the prospective areas. These units are often truncated by unconformities on the basin margins and change facies to nonporous strata basinward. The pinchouts of these porous units in proper structural orientations provide good petroleum prospects because they were already present during the maturation and migration of the Triassic-sourced hydrocarbons.