| Title | Tracing the subsurface sulfur cycle using isotopic and elemental fingerprinting: from the micro to the macro scale |
| Download | Download (whole publication) |
| |
| Licence | Please note the adoption of the Open Government Licence - Canada
supersedes any previous licences. |
| Author | Kingston, A W ;
Ardakani, O H; Stern, R A |
| Source | Hydrogen sulfide (H2S) in the Montney Formation, Western Canada Sedimentary Basin (WCSB) - investigating a complex issue, workshop proceeding; by Ardakani, O H (ed.); Pedersen, P K (ed.); Geological Survey of Canada, Open File 8878, 2022 p. 27-32, https://doi.org/10.4095/329789  Open Access |
| Year | 2022 |
| Publisher | Natural Resources Canada |
| Meeting | Montney H2S, Distribution and Origin Workshop; Calgary, AB; CA; February 9, 2022 |
| Document | open file |
| Lang. | English |
| Media | digital; on-line |
| Related | This publication is contained in Hydrogen sulfide (H2S) in
the Montney Formation, Western Canada Sedimentary Basin (WCSB) - investigating a complex issue, workshop proceeding |
| File format | pdf |
| Province | Alberta; British Columbia |
| NTS | 83C; 83E; 83F; 83G; 83J; 83K; 83L; 83M; 83N; 83O; 84B; 84C; 84D; 84E; 84F; 84G; 84L; 93I; 93O; 93P; 94A; 94B; 94G; 94H; 94I; 94J |
| Area | Fort St. John; Grande Prairie |
| Lat/Long WENS | -123.5000 -115.7500 59.0000 53.0000 |
| Subjects | fossil fuels; geochemistry; sedimentology; Science and Technology; Nature and Environment; Lower Triassic; sedimentary basins; petroleum resources; hydrocarbons; reservoirs; hydrogen sulphide; sulphur
geochemistry; isotopic studies; sulphur; sulphates; sulphides; modelling; models; source areas; source rocks; fluid migration; flow structures; structural controls; geological history; diagenesis; alteration; dolomitization; tectonic history; burial
history; crustal uplift; orogenies; pressure-temperature conditions; bedrock geology; structural features; faults; fractures; petrography; Montney Formation; Western Canada Sedimentary Basin; Laramide Orogeny; Methodology; Quality control;
Phanerozoic; Mesozoic; Triassic |
| Illustrations | geoscientific sketch maps; stratigraphic charts; photomicrographs; plots |
| Program | Energy Geoscience Clean Energy Resources - Decreasing Environmental Risk |
| Program | Geoscience for New Energy Supply (GNES) |
| Released | 2022 03 22 |
| Abstract | Hydrogen sulfide (H2S) is a toxic and corrosive gas that commonly occurs in deeply buried sedimentary systems. Understanding its distribution is paramount to creating safe and effective models of H2S
occurrence aiding in the identification of high-risk areas. Characterizing subsurface sulfur sources and H2S formation pathways would enhance these models leading to more accurate predictions of potential high H2S regions. However, gaps remain in our
understanding of the dominant formation processes and migration pathways of key ingredients for H2S production in the Lower Triassic Montney Formation of the Western Canada Sedimentary Basin (WCSB). Essential to this is assessing the reactants
necessary for H2S production, potential pathways for fluid migration, diagenetic history, and changes in redox conditions through time.
The Montney Formation has undergone several phases of diagenesis related to post-depositional alteration and
multiple cycles of tectonic burial and uplift. Early chemical alteration includes dolomitization and, in some cases, microbial reduction of porewater sulfate to sulfide that occurred prior to significant burial (Davies et al., 1997; Vaisblat et al.,
2021; Liseroudi et al., 2020, 2021). The most recent tectonic-related burial during the Laramide Orogeny resulted in burial depths in excess of 3-5 km (Ness, 2001; Ducros et al., 2017) leading to significant thermal and barometric alteration.
Associated with this orogenic activity was the reactivation of underlying faults (O'Connell et al., 1990) and development of fractures especially near the deformation front. These fractures provide conduits for fluid migration into the Montney that
combined with heat and pressure resulting in hydrocarbon generation, migration, and development of overpressure, notably in the western margin of the basin. In addition, high temperatures resulted in thermochemical sulfate reduction (TSR) leading to
the formation of H2S and subsequently pyrite.
We present an interpretation of the Montney subsurface sulfur cycle through the use of petrography, micro- and macro-scale geochemical analysis (isotopic and elemental) to illustrate the complexity of
this system. This work relies heavily on previous studies within and outside our research group and incorporates new analytical techniques to expand the toolbox. We aim to guide future research directions and activities by addressing issues related
to sampling and data quality issues, analytical approaches, and highlight knowledge gaps. |
| Summary | (Plain Language Summary, not published)
The origin and distribution of hydrogen sulfide (H2S) - a highly toxic and corrosive gas in conventional and unconventional resources of the Western
Canada Sedimentary Basin - was the subject of many studies. The Early Triassic Montney Formation, one of the major North American unconventional gas resources, contains a significant amount of H2S in some areas. Several research teams in western
Canada including the Geological Survey of Canada, the University of Calgary, and the University of British Columbia are investigating this complex issue. This workshop will provide a venue to discuss the latest scientific advancements on this topic
in order to reach a better understanding of the distribution, origin, and mitigation strategies to overcome the associated economic and environmental issues. This open file report presents the proceedings of the online workshop 'Hydrogen sulfide
(H2S) in the Montney Formation - investigating a complex issue' on February 9th, 2022 in Calgary Alberta, organized by the Canadian Society for Unconventional Resources (CSUR), Natural Resources Canada (NRCan), and University of Calgary. |
| GEOSCAN ID | 329789 |
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