|Title||Organic matter composition in the Alberta Montney Formation|
|Author||Ardakani, O H;
Cesar, J; Mackie, S J; Pedersen, P K; Reyes, J; Wood, J M|
|Source||Geoconvention 2021, abstracts; 2021 p. 1-3 Open
|Links||Online - En ligne|
|Alt Series||Natural Resources Canada, Contribution Series 20210158|
|Meeting||GeoConvention 2021; September 13-15, 2021|
|Media||paper; on-line; digital|
|NTS||84E/05; 84E/06; 84E/11; 84E/12; 84E/13; 84E/14|
|Lat/Long WENS||-120.0000 -119.0000 58.0000 57.2500|
|Subjects||fossil fuels; sedimentology; geochemistry; Nature and Environment; Science and Technology; petroleum resources; hydrocarbons; petrography; hydrocarbon migration; core samples; organic geochemistry;
bedrock geology; lithology; sedimentary rocks; mudstones; source rocks; reservoirs; sedimentary basins; Montney Formation; Western Canadian Sedimentary Basin; Doig Formation; Fernie Formation; Gordondale Member; Phanerozoic; Mesozoic; Jurassic;
|Program||Geoscience for New Energy Supply (GNES) Shale Reservoir Characterization|
|Released||2021 07 06|
Although the Montney Formation, part of the greater Triassic petroleum system in the Western Canadian Sedimentary Basin (WCSB), is one of the most prolific hydrocarbon resources in
North America, the organic matter composition and source of hydrocarbons in the Montney Formation is not well understood. Previous studies have considered the organic-rich middle Triassic Doig Formation and lower Jurassic Gordondale member of Fernie
Formation as major source rocks of the Triassic petroleum system (Allan and Creaney, 1991; Riediger et al., 1990; Ejezie, 2007). However, a regional organic petrography study in Alberta (Beaton et al., 2010; Reyes et al., 2010), as well as more
recent regional sedimentology, sequence stratigraphy, and organic geochemistry studies (Crombez et al., 2017; Euzen et al., 2018; Romero-Sarmiento et al., 2016; Becerra et al., 2020), have reported primary organic matter in organic-rich intervals
within the Montney Formation as possible internal source(s) of hydrocarbons. In contrast, other regional organic, transmitted light, and scanning electron microscopy (SEM) petrography studies of the Montney tight-gas and hydrocarbon liquids fairway
in British Columbia and adjacent Alberta suggest the organic matter is dominantly secondary and derived from liquid oil or bitumen that migrated and was subsequently thermally cracked (Sanei et al., 2015; Wood et al., 2015, 2018a, b, 2020). In this
study, we re-examined a sub-set of organic-rich interval samples from eleven cores across the Montney Formation in Alberta, part of the Beaton et al. (2010) data release, to investigate the origin and composition of the organic matter in the Montney
Formation using legacy Rock-Eval6(TM) as well as collected new programmed pyrolysis, organic geochemistry, and petrography and fluorescence microscopy data at the Geological Survey of Canada.
The results of this study show that intermittent thin
(2-10 cm thick) relatively organic-rich mudstone intervals (TOC less than or equal to 1 wt. %) in the Montney Formation in central and western Alberta contain primary organic matter that can be considered as a local source of hydrocarbons in the
Montney Formation in addition to other major adjacent organic-rich source rocks (i.e., Doig and Gordondale) within the Triassic petroleum system. These results are in agreement with Becerra et al. (2020) observation from elsewhere in Alberta.
However, the thin, relatively organic-rich mudstone intervals in the Alberta Montney cannot be considered as the only source of the vast amount of petroleum (solid bitumen, oil, gas) in the formation. This new evidence suggests that the Montney
Formation in Alberta can be considered as a hybrid unconventional hydrocarbon reservoir. A comprehensive regional organic petrography and geochemistry study throughout the basin will help to identify the major hydrocarbon families and their sources
in the WCSB Triassic petroleum system.
|Summary||(Plain Language Summary, not published)|
The conference presentation discusses the origin and composition of organic matter in the Montney Formation, a major unconventional resource in western
Canada. The origin of organic matter in the Montney Formation is long debated. This work tries to shed some light to better understand OM origin in the Montney Formation.