Petroleum Resource Assessment, Eagle Plain Basin and environs, Yukon Territory, Canada

The Eagle Plain Basin and its environs is a potentially prospective petroleum province in the Yukon. Extensive initial exploration in this area, focused on discovering crude oil, identified 83.7 Bcf of natural gas and 11.05 MMbbls of crude oil, with 33 wells, many of which had shows of petroleum in other zones, throughout the succession and across the geographic extent of the basin. A probabilistic petroleum assessment of 15 petroleum plays suggests that an expected 5.971 Tcf of natural gas and 425.95 MMbbls of crude oil remain to be discovered, as part of a total resource endowment in 146 accumulations of crude oil and natural gas containing between 2.379 Tcf to 12.0 Tcf of natural gas, and 132 MMbbls to 926 MMbbls of crude oil. This study differs significantly from previous estimates of undiscovered potential, which were less optimistic. The total expected petroleum endowment of the Cambrian to Middle Devonian carbonate succession is 1327.86 Bcf of natural gas, which remains an important secondary deeper exploration target. The main target is the Permo-Carboniferous succession, with three main potential reservoirs, at the base (Tuttle Formation), in the middle (Hart River Formation) and at the top (Jungle Creek Formation) of the succession. The Tuttle Formation is expected to have resources of 323.02 Bcf of natural gas and 68.95 MMbbls of crude oil. Another 1823.32 Bcf and 155.09 MMbbls are inferred for the Hart River Formation, while the Jungle Creek Formation is expected to contain 2231.8 Bcf and 104.89 MMbbls. The expected potential in the Mesozoic succession is 349.34 Bcf and 107.81 MMbbls, an important up-hole interval. While the entire section is prospective, plays that target structural and stratigraphic prospects in the upper part of the Paleozoic succession are the best targets, as these form major traps at and near the top of the succession that contain thermally mature sources, below major regional seals, which are commonly involved in Laramide structures. Predicted undiscovered pool sizes point toward success accompanying the continued exploration of plays in the Permian and Carboniferous successions, with a new focus on Jungle Creek Formation sandstones. These results are consistent with the exploration history, the stratigraphic architecture and the analysis of petroleum systems. Intriguing plays exist associated with the stratigraphic opportunities for entrapment in Paleozoic carbonates against the Richardson Trough, but these appear to be higher risk/reward targets than the continued exploration of the uppermost Paleozoic succession. Additional conceptual play concepts, including those in the Devonian Imperial and Jurassic Porcupine River formations, which have indications of petroleum occurrence, were not quantitatively assessed.