| Titre | Gas geochemistry and the origins of H2S in the Montney Formation |
| Télécharger | Téléchargement (publication entière) |
| |
| Licence | Veuillez noter que la Licence du gouvernement
ouvert - Canada remplace toutes les licences antérieures. |
| Auteur | Lacerda Silva, P; Chalmers, G R; Bustin, A M M; Bustin, R M |
| Source | Hydrogen sulfide (H2S) in the Montney Formation, Western Canada Sedimentary Basin (WCSB) - investigating a complex issue, workshop proceeding; par Ardakani, O H (éd.); Pedersen, P K (éd.); Commission géologique du Canada, Dossier public 8878, 2022 p. 37-44, https://doi.org/10.4095/329794  Accès ouvert |
| Année | 2022 |
| Éditeur | Ressources naturelles Canada |
| Réunion | Montney H2S, Distribution and Origin Workshop; Calgary, AB; CA; février 9, 2022 |
| Document | dossier public |
| Lang. | anglais |
| DOI | https://doi.org/10.4095/329794 |
| Media | numérique; en ligne |
| Référence reliée | Cette publication est contenue dans Hydrogen
sulfide (H2S) in the Montney Formation, Western Canada Sedimentary Basin (WCSB) - investigating a complex issue, workshop proceeding |
| Formats | pdf |
| Province | Alberta; Colombie-Britannique |
| SNRC | 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 |
| Région | Fort St. John; Dawson Creek; Grande Prairie; Whitecourt; Rivière de la Paix; Edson; Hinton |
| Lat/Long OENS | -123.5000 -115.7500 59.0000 53.0000 |
| Sujets | Trias inférieur; bassins sédimentaires; ressources pétrolières; hydrocarbures; gaz; reservoirs; géochimie des hydrocarbures; hydrogene sulfuré; fluides du réservoir; gaz carbonique; maturation thermique;
migration des hydrocarbures; production d'hydrocarbure; structures flui dales; contrôles structuraux; etudes isotopiques; soufre; isotopes d'oxygène; cadre tectonique; géochimie du soufre; analyses au microscope électronique à balayage; analyses
spectroscopiques; analyses par diffraction des rayons x; anhydrite; roches mères; géochimie des eaux souterraines; directives d'exploration; gaz sulfreux; méthane; Formation de Montney ; Bassin sédimentaire de l'ouest du Canada; Graben de Fort St.
John ; Formation de Charlie Lake ; Formation d'Halfway ; combustibles fossiles; géochimie; géologie structurale; minéralogie; Sciences et technologie; Nature et environnement; Phanérozoïque; Mésozoïque; Trias; Paléozoïque; Dévonien |
| Illustrations | cartes de localisation; cartes géolscientiques généralisées; graphiques |
| Programme | Les géosciences de l'énergie Ressources d'énergie propre - réduire les risques environnementaux |
| Diffusé | 2022 03 22 |
| Résumé | (disponible en anglais seulement)
The geology of the Montney Formation and the geochemistry of its produced fluids, including nonhydrocarbon gases such as hydrogen sulfide were investigated for
both Alberta and BC play areas. Key parameters for understanding a complex petroleum system like the Montney play include changes in thickness, depth of burial, mass balance calculations, timing and magnitudes of paleotemperature exposure, as well as
kerogen concentration and types to determine the distribution of hydrocarbon composition, H2S concentrations and CO2 concentrations. Results show that there is first-, second- and third- order variations in the maturation patterns that impact the
hydrocarbon composition. Isomer ratio calculations for butane and propane, in combination with excess methane estimation from produced fluids, are powerful tools to highlight effects of migration in the hydrocarbon distribution. The present-day
distribution of hydrocarbons is a result of fluid mixing between hydrocarbons generated in-situ with shorter-chained hydrocarbons (i.e., methane) migrated from deeper, more mature areas proximal to the deformation front, along structural elements
like the Fort St. John Graben, as well as through areas of lithology with higher permeability.
The BC Montney play appears to have hydrocarbon composition that reflects a larger contribution from in-situ generation, while the Montney play in
Alberta has a higher proportion of its hydrocarbon volumes from migrated hydrocarbons. Hydrogen sulphide is observed to be laterally discontinuous and found in discrete zones or pockets. The locations of higher concentrations of hydrogen sulphide do
not align with the sulphate-rich facies of the Charlie Lake Formation but can be seen to underlie areas of higher sulphate ion concentrations in the formation water. There is some alignment between CO2 and H2S, particularly south of Dawson Creek;
however, the cross-plot of CO2 and H2S illustrates some deviation away from any correlation and there must be other processes at play (i.e., decomposition of kerogen or carbonate dissolution). The sources of sulphur in the produced H2S were
investigated through isotopic analyses coupled with scanning electron microscopy, energy dispersive spectroscopy, and mineralogy by X-ray diffraction.
The Montney Formation in BC can contain small discrete amounts of sulphur in the form of
anhydrite as shown by XRD and SEM-EDX results. Sulphur isotopic analyses indicate that the most likely source of sulphur is from Triassic rocks, in particular, the Charlie Lake Formation, due to its close proximity, its high concentration of
anhydrite (18-42%), and the evidence that dissolved sulphate ions migrated within the groundwater in fractures and transported anhydrite into the Halfway Formation and into the Montney Formation. The isotopic signature shows the sulphur isotopic
ratio of the anhydrite in the Montney Formation is in the same range as the sulphur within the H2S gas and is a lighter ratio than what is found in Devonian anhydrite and H2S gas. This integrated study contributes to a better understanding of the
hydrocarbon system for enhancing the efficiency of and optimizing the planning of drilling and production operations. Operators in BC should include mapping of the Charlie Lake evaporites and structural elements, three-dimensional seismic and
sulphate ion concentrations in the connate water, when planning wells, in order to reduce the risk of encountering unexpected souring. |
| Sommaire | (Résumé en langage clair et simple, non publié)
L'origine et la distribution du sulfure d'hydrogène (H2S) - un gaz hautement toxique et corrosif présent dans les ressources conventionnelles et
non conventionnelles du bassin sédimentaire de l'Ouest canadien - ont fait l'objet de nombreuses études. La formation de Montney du Trias précoce, l'une des principales ressources en gaz non conventionnel d'Amérique du Nord, contient une quantité
importante de H2S dans certaines zones. Plusieurs équipes de recherche de l'Ouest canadien, dont la Commission géologique du Canada, l'Université de Calgary et l'Université de la Colombie-Britannique, étudient cette question complexe. Cet atelier
permettra de discuter des dernières avancées scientifiques sur ce sujet afin de mieux comprendre la distribution, l'origine et les stratégies d'atténuation pour surmonter les problèmes économiques et environnementaux associés. Ce rapport de dossier
public présente le compte rendu de l'atelier en ligne << Hydrogen sulfide (H2S) in the Montney Formation - investigating a complex issue >> qui a eu lieu le 9 février 2022 à Calgary (Alberta) et qui a été organisé par la Canadian Society for
Unconventional Resources (CSUR), Ressources naturelles Canada (RNCan) et l'Université de Calgary. |
| GEOSCAN ID | 329794 |
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