| Drill cutting samples from low-permeability Nikanassin strata collected in the Deep Basin of Alberta are the principal dataset used for reservoir characterization performed on this stratigraphic interval. Potential reservoir intervals are represented mainly by sub-litharenites in which porosity and permeability, measured on over 150 samples, range from 3% to 10%, and 0.03 to 0.22 millidarcy, respectively for the majority of the samples. Pervasive quartz overgrowth and subsequent calcite precipitation are the principal cementing phases, which also include variable amounts of clays and organic matter staining. Dominant pore geometries correspond to micropores from partial alteration/dissolution of chert and feldspar fragments, with scattered presence of remnant intergranular pores, slot -- like pores and microfractures. Higher permeability values are found, likely associated with smaller proportions of calcite and clay cements, especially within the lowermost portion of the Nikanassin strata, which also accounts the higher gas production potential within the investigated stratigraphic interval. |
