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TitreAssessment of potential impacts of shale gas development on surficial aquifers
AuteurRivard, C; Lavoie, D; Lefebvre, R; Séjourné, S; Bordeleau, G; Duchesne, M J
SourceNew Brunswick Exploration, Mining and Petroleum conference program and abstracts volume; 2014 p. 84
LiensOnline - En ligne
Année2014
Séries alt.Secteur des sciences de la Terre, Contribution externe 20140194
ÉditeurNew Brunswick Department of Mines and Energy
RéunionNew Brunswick 2014 Exploration, Mining and Petroleum conference; Fredericton; CA; Novembre 2-4, 2014
Documentlivre
Lang.anglais
Mediapapier; en ligne; numérique
Formatspdf
ProvinceColombie-Britannique
Sujetsschistes; gaz; aquifères; eau souterraine; ressources en eau souterraine; régimes des eaux souterraines; Bassin d'Horn River ; hydrogéologie; combustibles fossiles; Mésozoïque; Trias; Paléozoïque; Dévonien
ProgrammeGas de schiste - les eaux souterraines, Géosciences environnementales
Résumé(disponible en anglais seulement)
Shale gas has more than doubled the natural gas resource base of Canada (5,000 TCF of gas in place). Currently, natural gas and associated liquids are produced from Devonian shales in the Horn River basin and from the Triassic Montney shales (British Columbia). Other shales with gas potential are being evaluated, including the Lower Carboniferous Frederick Brook Shale in New Brunswick. However, hydrocarbon exploration and production may involve risks to groundwater quality and these need to be assessed. Hydraulic fracturing has been used to stimulate production in conventional oil and gas reservoirs for more than 60 years. However, recent multi-stage fracturing in horizontal wells uses greater amounts of water and chemicals, as well as higher pressure than in conventional reservoirs. In order to minimize environmental risks and, in particular, groundwater contamination, it is essential to evaluate exploration and production conditions. These groundwater-related risks are primarily associated to engineering issues, including the casing integrity and surface activities such as transport, storage and treatment of fracturing and flowback fluids. Concerns have also been raised with respect to groundwater contamination that could result from potential fracture interconnections between the shale unit and surficial aquifers. A report of the Canadian Council of Academia on potential environmental impacts of shale gas identified groundwater as a theme where new geoscience knowledge is critically needed. A methodology is being developed at the Geological Survey of Canada to evaluate the likelihood of natural pathways linking target shales to surficial aquifers. This study is carried out using existing hydrogeological, geological, and exploration data such as deep seismic lines, borehole geophysics, water-well log data and rock geochemistry, as well as new fieldwork and lab work to complement existing information. New work includes shallow subsurface seismic surveys, outcrop fracture mapping, shallow drilling and borehole geophysics, core sample tests, hydraulic testing, and groundwater and soil sampling for hydrocarbon concentration and isotopic fingerprinting. This research also includes assessment of geomechanical properties through laboratory tests and well-log analyses, as well as hydrogeological modelling to study the system behaviour and potential effects of fracturing on fluid migration. This study will allow the development of tools for the identification of zones having the least constraints for shale gas production and zones where it might be necessary to modify industry's current practices in order to minimize potential impacts to groundwater resources. The methodology could serve as a basis for the development of a regulatory framework within the context of responsible energy development.
Résumé(Résumé en langage clair et simple, non publié)
Les risques de contamination de l'eau souterraine lors des activités associées à l'exploration et au développement du gaz de shale furent soulevés dans un rapport récent du Conseil Canadien des Académies. La CGC a initié, en 2012, un projet de recherche visant à développer un protocole de recherche pour évaluer la présence potentielle de chemins naturels de migration entre les shales en profondeur et les aquifères prèsd e la surface. Le comité organisateur du congrès de 2014 Exploration, Mines et Pétrole au Nouveau Brunswick nous a invité à présenter les résultats actules de nos activités de recherche dans le sud du Québec.
GEOSCAN ID295150