| Titre | Possible pore structure deformation effects on the shale gas enrichment: an example from the Lower Cambrian shales of the eastern Upper Yangtze Platform, south China |
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| Auteur | Ma, Y; Ardakani, O H ; Zhong, N; Liu, H; Huang, H; Larter, S; Zhang, C |
| Source | International Journal of Coal Geology vol. 217, 103349, 2019 p. 1-22, https://doi.org/10.1016/j.coal.2019.103349 |
| Image |  |
| Année | 2019 |
| Séries alt. | Ressources naturelles Canada, Contribution externe 20180450 |
| Éditeur | Elsevier |
| Document | publication en série |
| Lang. | anglais |
| DOI | https://doi.org/10.1016/j.coal.2019.103349 |
| Media | papier; en ligne; numérique |
| Formats | pdf (Adobe® Reader®); html |
| Région | Chongqing; Chong; Guizhou; Shanxi; Sichuan; Hubei |
| Lat/Long OENS | 105.5000 110.0000 33.2500 27.7500 |
| Lat/Long OENS | 105.5000 110.0000 33.2500 27.7500 |
| Sujets | Cambrien inférieur; ressources pétrolières; exploration pétrolière; hydrocarbures; gaz; roches reservoirs; taille des pores; structure des pores; géologie du substratum rocheux; lithologie; roches
sédimentaires; schistes; caractéristiques structurales; failles; microscopie électronique à balayage; pression capillaire; milieu sédimentaire; carbonate; antécédents géologiques; antécédents tectoniques; antecedents thermiques; maturation thermique;
soulèvement de la croûte; crevasses; migration des hydrocarbures; puits; pétrographie; analyses par diffraction des rayons x; géochimie organique; analyses minéralogiques; Bassin de Sichuan ; combustibles fossiles; sédimentologie; tectonique;
géochimie; minéralogie; Sciences et technologie; Nature et environnement; Phanérozoïque; Mésozoïque; Trias; Paléozoïque; Cambrien |
| Illustrations | cartes de localisation; cartes géolscientiques généralisées; coupes transversales; photographies; profils; coupes lithologiques; tableaux; photomicrographies; graphique à barres; graphiques;
représentations schématiques |
| Programme | Les géosciences pour les nouvelles sources d'énergie Caractérisation des réservoirs de schiste |
| Diffusé | 2019 11 21 |
| Résumé | (disponible en anglais seulement)
Shale gas reservoir performance and canister desorption experiments of the Lower Cambrian organic-rich shales in the eastern Upper Yangtze Platform reveal a
significant difference in shale gas content between the Dabashan arc-like fold-thrust belt in northeastern Chongqing (Deformed Zone) and the slightly folded area in southeastern Chong (Non-deformed Zone). Integrated pore characterization methods
including scanning electron microscopy (SEM), low-temperature N2 and CO2 adsorption, and mercury injection capillary pressure (MICP) analyses were comparatively conducted in both areas in order to examine shale gas reservoir pore size variations and
thus the possible microscopic pore structure controls on shale gas enrichment.
The Lower Cambrian shales in both Deformed Zone (DZ) and Non-deformed Zone (NDZ) were deposited in the deep-water shelf and show similar organic matter richness and
thermal maturity. The majority of organic matter (OM)-hosted pores in DZ samples are in nanoscale size range with the dominance of micro-fractures within the OM or at the interface of OM and minerals. In contrast, OM-hosted meso- (2-50 nm) to
macropores (> 50 nm) are the dominant pore types in the NDZ samples. OM-hosted micropores (< 2 nm) are abundant in both zones. Helium ion microscopy observations further confirm the presence of OM-hosted micropores in the studied samples.
Mineral-hosted pores in carbonate minerals are abundant in both zones, while dissolution rims around carbonate minerals are more abundant in NDZ samples.
The Dabashan arc-like fold-thrust belt took place by the end of the Late Triassic, while the
Lower Cambrian shales have reached thermal maturity peak. OM-hosted meso- (2-50 nm) to macropores (> 50 nm) in DZ samples are most probably collapsed during structural deformation related to tectonic compression, while micropores due to their smaller
size survived the tectonic stress. The OM-hosted micropores are the main storage space for adsorbed gas in the DZ area. The dominance of micro-pores in DZ and lack of connection between those pores and matrix pores led to higher gas content in DZ
samples. On the contrary, the well-connected OM-hosted pore network in NDZ allows easier gas flow in the rock matrix that eventually led to significant gas leakage during uplift and exhumation and lower gas content in this zone. The results of this
study suggest that structural deformation can potentially change the pore structure of shales and thus shale gas content which has major significance for shale gas exploration and development in south China where had experienced complex tectonic
movements. |
| Sommaire | (Résumé en langage clair et simple, non publié)
Cette étude examine les effets possibles de la déformation structurelle sur les caractéristiques des pores des réservoirs de gaz de
schiste. |
| GEOSCAN ID | 314559 |
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