| Titre | Unconventional gas geochemistry - an emerging concept after 20 years of shale gas development? |
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| Auteur | Cesar Colmenares, J |
| Source | Minerals vol. 12, issue 10, 1188, 2022 p. 1-13, https://doi.org/10.3390/ min12101188 |
| Image |  |
| Année | 2022 |
| Séries alt. | Ressources naturelles Canada, Contribution externe 20220349 |
| Éditeur | MDPI |
| Document | publication en série |
| Lang. | anglais |
| DOI | https://doi.org/10.3390/ min12101188 |
| Media | papier; numérique; en ligne |
| Formats | pdf |
| Sujets | gaz; isotopes de carbone; ethane; géochimie; Sciences et technologie |
| Illustrations | tableaux; représentations graphiques combinées; diagrammes |
| Programme | Géosciences de l'énergie La coordination du programme |
| Diffusé | 2022 09 22 |
| Résumé | (disponible en anglais seulement)
Geochemical studies of gases from low-permeability reservoirs have raised new questions re-garding the chemical and stable isotope systematics of gas
hydrocarbons. For instance, the pos-sibility of thermodynamic equilibrium is recurrently in discussion. However, it is not clear whether there is anything "unconventional" in the way these systems continue to be studied. Using molecular and stable
carbon isotope data from North American unconventional and con-ventional reservoirs, this research has applied two parameters that well describe key transfor-mation stages during gas generation. The d13C of ethane and the C2/C3 ratio increase from
base-line values (<1%Ro, prominent kerogen cracking) until a first inflexion at 1.5%Ro. The same in-flexion leads to 13C depletion of ethane and a rapidly increasing C2/C3 ratio as hydrocarbon cracking becomes prominent. The transition between these
two stages is proposed to be a crossover from equilibrium to non-equilibrium conditions. There is no evidence for these char-acteristics to be limited to low-permeability reservoirs. Unconventional gas geochemistry should represent an approach that
acknowledges that chemical and isotope distributions are not ruled by only one mechanism but several and at specific intervals of the thermal history. |
| Sommaire | (Résumé en langage clair et simple, non publié)
Cette étude met en évidence l'importance de la géochimie des gaz non conventionnels en tant qu'approche qui considère différents mécanismes de
fractionnement moléculaire et isotopique (par exemple, la cinétique et l'équilibre) dans les hydrocarbures gazeux. Les paramètres géochimiques tels que la composition isotopique du carbone de l'éthane et le rapport éthane/propane ont montré des
tendances caractéristiques qui ont prouvé la variabilité des mécanismes de fractionnement à des stades spécifiques de l'évolution thermique des hydrocarbures. |
| GEOSCAN ID | 330872 |
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