A petroleum resource assessment of the Huron Domain area, southern Ontario
Authors: Chen Z , Hannigan P , Carter T R , Liu X , Crowe R , Obermajer M 
Published: April 2021

The Geological Survey of Canada has quantitatively assessed oil and gas resources in self-sourced and self-retained fine-grained clastic (shale) reservoirs within the Upper Ordovician Collingwood and Rouge River members, as well as the undiscovered potential oil
and gas resources in Paleozoic conventional reservoirs, incorporating data from a site formerly proposed for a Low and Intermediate deep geologic repository and regional data from southern Ontario. If these two Upper Ordovician shale units are treated as separate resource plays, both fail to meet
the minimum criteria set out by the United States Geological Survey (USGS) that define a hydrocarbon resource play. When combined however, the two units can be treated as a continuous sedimentary package and, therefore, can be treated as a single resource play.
In this report, only the technically recoverable resources are reported. Technically recoverable resources are defined as the volume of oil and gas that could be produced with technology available at the time of the present report, regardless of commodity price, production cost and the cost of
bringing the products to markets.
The cut-off for the volumetric calculation is 0.5 meters of cumulative hydrocarbon-saturated rock column, which is calculated from hydrocarbon saturated porosity times gross thickness of the combined Collingwood and Rouge River shale units. The 0.5 meter cut-off is equivalent to a hydrocarbon
saturated porosity &amp;gt;2.5% and combined gross thickness &amp;gt;20 meters. The cut-off is in general consistent with the geological criteria for defining the shale play boundary as described by the USGS and mentioned above. The total area defined by the reservoir cut-off is smaller
than the area within the shale play boundary and is regarded as the risked prospective area by reservoir criterion.
The geographic distribution of the predicted hydrocarbon resources of the Upper Ordovician Collingwood and Rouge River shale units indicates that a large volume of the potential hydrocarbon resources of these two shale units occur in the Appalachian Basin portion of southern Ontario. Only a small
quantity of the reservoir-risked resource is predicted to occur in the southeastern part of the Nuclear Waste Management Organization (NWMO) study area.
Among the undiscovered technically recoverable unconventional resources within the study area, the mean totals are 11.7 million barrels of shale oil (MMBO), with a fractile (F95-F05, respectively) range from 6.4-19.2 MMBO and 8.0 billion cubic feet of continuous gas (Bcf), with a fractile range from
4.6-12.7 Bcf. Regarding conventional resource, mean totals of 6.8 million barrels of conventional oil and 52.3 Bcf of conventional gas are estimated to occur in the study area, although subjectively this estimate is considered to be optimistic.
The ranges of resource estimates reflect the geologic uncertainty of the source-reservoir rock systems and spatial extrapolation of resource mapping from sparse well controls. Much of the uncertainty is related to models constructed to estimate the quantity of oil remaining in the source rocks
following migration and the quality of oil and gas stored in conventional reservoirs. Only a small portion of the potential resource lies within the NWMO study area (Huron Domain). The bulk of the potential hydrocarbons that are estimated to be trapped within the lithostratigraphic members is
considered to be exceptionally low in the NWMO study area due to a combination of low permeability, contrasting lithologies, low formation pressures, low degrees of thermal maturation, high oil viscosity impeding hydrocarbon fluid flow and poor oil show index (S1/TOC
&amp;lt;1).