Defining the natural fracture network in a shale gas play and its cover succession: The case of the Utica Shale in eastern Canada.

Ladevèze, Pierre; Séjourné, Stephan; Rivard, Christine; Lavoie, Denis; Lefebvre, René ORCID: https://orcid.org/0000-0002-7938-9930 et Rouleau, Amélie (2018). Defining the natural fracture network in a shale gas play and its cover succession: The case of the Utica Shale in eastern Canada. Journal of Structural Geology , vol. 108 . pp. 157-170. DOI: 10.1016/j.jsg.2017.12.007.

Prévisualisation

PDF Disponible sous licence Creative Commons Attribution Non-commercial No Derivatives. Télécharger (10MB) | Prévisualisation

Résumé

In the St. Lawrence sedimentary platform (eastern Canada), very little data are available between shallow fresh water aquifers and deep geological hydrocarbon reservoir units (here referred to as the intermediate zone). Characterization of this intermediate zone is crucial, as the latter controls aquifer vulnerability to operations carried out at depth. In this paper, the natural fracture networks in shallow aquifers and in the Utica shale gas reservoir are documented in an attempt to indirectly characterize the intermediate zone. This study used structural data from outcrops, shallow observation well logs and deep shale gas well logs to propose a conceptual model of the natural fracture network. Shallow and deep fractures were categorized into three sets of steeply-dipping fractures and into a set of bedding-parallel fractures. Some lithological and structural controls on fracture distribution were identified. The regional geologic history and similarities between the shallow and deep fracture datasets allowed the extrapolation of the fracture network characterization to the intermediate zone. This study thus highlights the benefits of using both datasets simultaneously, while they are generally interpreted separately. Recommendations are also proposed for future environmental assessment studies in which the existence of preferential flow pathways and potential upward fluid migration toward shallow aquifers need to be identified.

Type de document:	Article
Informations complémentaires:	Embargo
Mots-clés libres:	natural fracture characterization; analogs; conceptual models; shale gas; Utica Shale
Centre:	Centre Eau Terre Environnement
Date de dépôt:	29 janv. 2018 21:47
Dernière modification:	11 févr. 2022 14:33
URI:	https://espace.inrs.ca/id/eprint/6775

Gestion Actions (Identification requise)

Modifier la notice