Alberta's Unconventional Shale Resource Potential
Beaton, Andrew; Rokosh, D.; Hein, Frances J.
The Alberta portion of the Western Canadian Sedimentary Basin includes no less than 18 shale dominated formations that may have unconventional resource potential. Seven key shale/siltstone formations that exhibit favourable resource characteristics and have attracted industry interest are evaluated. Porosity/permeability, organic content, Rock-Eval parameters, adsorption isotherm capacity, organic petrology, mineralogy, fluid saturation, vitrinite reflectance and geophysical log characteristics were used to generate in-place resource estimates and suggest preferred resource targets, geographic locations of initial development, fluid types and reservoir characteristics conducive to development.
Alberta's shale resource estimates are based on a new probabilistic geostatistical model. Five units/formations show immediate potential in Alberta, namely the Duvernay-Muskwa, Montney, Nordegg and the Exshaw/Banff (sometimes referred to as ‘Alberta Bakken'). The study also includes a preliminary assessment of Colorado, Wilrich, Rierdon and Bantry stratigraphic intervals. These were systematically mapped, sampled and evaluated for hydrocarbon potential. A total of 3385 new samples (5400 individual analyses) were evaluated in this study.
The total combined P50 values for the Duvernay, Muskwa, Montney, Banff/Exshaw, Wilrich, Nordegg and Rierdon show significant unconventional resources in-place for Alberta; specifically, 3406 Tcf natural gas, 58.5 billion barrels of natural gas liquids and 432.5 billion barrels of oil. These estimates exclude conventional resources/reserves. Colorado Group results are preliminary and not included in the estimates; however, initial results indicate significant potential for this group of formations.
This study marks the first comprehensive unconventional resource evaluation of Alberta. Prior to this study, relatively few geochemical and petrophysical data from Alberta shale-dominated successions were available for resource evaluation. Extensive detailed sampling and analysis performed under this study allowed a robust geostatistical evaluation of hydrocarbon fluid type and resource distribution. A key result is the identification of NGL/condensate trends associated with shale horizons. This study validates Alberta's huge unconventional resource potential.
AAPG Search and Discovery Article #90163©2013AAPG 2013 Annual Convention and Exhibition, Pittsburgh, Pennsylvania, May 19-22, 2013