| Title | Evidence of hydrocarbon generation and overpressure development in an unconventional reservoir using fluid inclusion and stable isotope analysis from the early Triassic, Western Canadian Sedimentary
Basin |
| |
| Author | Kingston, A W ;
Haeri Ardakani, O; Samson, I |
| Source | Frontiers in Earth Science vol. 10, 918898, 2022 p. 1-21, https://doi.org/10.3389/feart.2022.918898  Open Access |
| Image |  |
| Year | 2022 |
| Alt Series | Natural Resources Canada, Contribution Series 20220115 |
| Publisher | Frontiers in Earth Science |
| Document | serial |
| Lang. | English |
| Media | paper; digital; on-line |
| File format | pdf |
| Province | Alberta; British Columbia |
| NTS | 83E; 83F; 83K; 83L; 83M; 83N; 84C; 84D; 84E; 84F; 84K; 84L; 93G; 93H; 93I; 93J; 93O; 93P; 94A; 94B; 94G; 94H; 94I; 94J |
| Lat/Long WENS | -123.0000 -116.0000 59.0000 53.0000 |
| Subjects | geochemistry; igneous and metamorphic petrology; hydrocarbons; hydrocarbon generation; reservoirs; reservoir fluid analyses; stable isotope studies; spectroscopy; fluid inclusions; inclusions; models;
modelling; Western Canadian Sedimentary Basin; Montney Formation; Triassic |
| Illustrations | location maps; photographs; photomicrographs; tables; histograms; spectra; cross-plots |
| Program | Energy Geoscience Program Coordination |
| Released | 2022 06 20 |
| Abstract | Deep burial of sedimentary basins results in the development of complex diagenetic environments influenced by pressure, temperature, and metasomatic chemical processes. Fracture systems resulting from
deep tectonic-related burial can provide archives of physio-chemical characteristics during burial helping unravel diagenetic events such as hydrocarbon migration and paleobarometry. The Early Triassic Montney Formation in the Western Canadian
Sedimentary Basin is a highly productive unconventional hydrocarbon reservoir that has undergone multiple phases of tectonic-related burial and uplift resulting in the formation of a series of calcite-filled fracture systems. These fracture systems
occur as vertical to sub-vertical fractures, brecciated zones, and horizontal bedding-plane parallel fractures that are rich in co-occurring, but not co-genetic aqueous and petroleum fluid inclusion assemblages. Fluid inclusion microthermometry,
Raman spectroscopy, and stable isotope analysis of these fracture systems and host rock reveals paleobarometric and temperature conditions during fracture formation. Vertical fractures formed at temperatures exceeding 142°C during peak burial
associated with the Laramide orogeny ~50 Ma. Similarities in modeled oxygen isotope values of calcite parent fluids and pore water implicate locally sourced carbonate in fracture calcite. Therefore, low permeability and closed system-like conditions
were prevalent throughout initial fracture formation and cementation. Petrographic analysis of brecciated and horizontal fractures show evidence of hydrocarbon generation and migration into fracture-filling calcite. Modeling of petroleum inclusion
paleobarometry indicates entrapment pressures approaching or even exceeding lithostatic pressure consistent with the development of overpressure associated with the thermal maturation of organic matter following peak burial. Combined use of aqueous
and petroleum fluid inclusions in this deeply buried sedimentary system offers a powerful tool for better understanding diagenetic fluid flow, the timing of hydrocarbon migration/maturation, and helps constrain the pressuretemperature history
important for characterizing economically important geologic formations. |
| Summary | (Plain Language Summary, not published)
The Montney Formation is an important hydrocarbon resource with a complex history of diagenesis and alteration. Analysis of aqueous and petroleum fluid
inclusions provides a record of fluid migration through the Montney including information about past temperature-pressure conditions. Aqueous inclusions indicate that fractures formed at peak burial during maximum pressure and temperature conditions.
Modeling petroleum inclusions suggests that overpressure developed due to the formation of hydrocarbons within the system following peak burial. Stable isotope analysis indicates locally sourced carbonate illustrating the closed system behavior of
the Montney. |
| GEOSCAN ID | 330214 |
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