Anticosti Island, Quebec: Updated Review of a Major Shale Play in North Eastern America

Dorrins, Peter K. (Junex inc.) | Marcil, Jean-Sebastien (Junex inc.) | Lavoie, Jeremie (Junex inc.) | Mechti, Nabila (Junex inc.)



Located in the Gulf of St. Lawrence in Quebec, Anticosti Island extends over a length of 220 km and a maximum width of 56 km and covers an area of 7,943 sq-km (3000 sq-mi). Anticosti is a large ESE-WNW oriented structure situated along the Laurentia passive margin of Ordovician carbonates that extends from western Texas to Newfoundland (figure 1). The geological units forming the island are of Paleozoic age, ranging from the Cambrian to the end of Silurian. The territory, almost unhabited, has large subsurface areas virtually unknown since very few exploration wells were drilled on the island. However, various data accumulated over sixty years now allow us to evaluate the petroleum potential of the region. The current exploration phase recognized the potential of the Middle Ordovician Macasty Shale as a liquid-rich resource play (potential for light oil/condensate production).

The Macasty Shale has properties which compares favorably with other North American shale resource plays and which may be a positive indicator for potential resources initially-in-place. Technical evaluation indicates that the level of organic richness, the thermal maturity, the mineralogy, the formation pressure and temperature, as well the structural features observed thus far in the Macasty in the Deep Macasty Fairway compares favorably with published findings for the oil-rich Utica/Point Pleasant Shale in Ohio and the Eagle Ford Shale in Texas. Resources assessment studies (P50 - Best Estimate) recently published by different groups corroborate the analytical results and the interpretation of the authors concerning the high hydrocarbon potential of the Anticosti Basin. For the Macasty Shale only, current estimations established the potential oil initially in-place (OIIP) to be over 40 billion barrels.

According to recently released by the Government of Quebec report, the exploitation of hydrocarbons on the island would be likely to meet up to 113% of the current annual consumption of Québec's natural gas and up to 9% of oil consumption. It could represent an annual intake of more than two billion dollars to the Quebec GDP. Considering the lifetime of the project which could extend over 75 years, activities on Anticosti Island could create and maintain on average between 2200 and 2600 direct and indirect jobs annually (Quebec Government, 2016).