| Title | Assessing potential impacts of shale gas development on shallow aquifers through upward fluid migration: a multi-disciplinary approach applied to the Utica Shale in eastern Canada |
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| Author | Rivard, C ;
Bordeleau, G; Lavoie, D; Lefebvre, R; Ladevèze, P; Duchesne, M
J; Séjourné, S; Crow, H; Pinet, N; Brake, V; Bouchedda, A; Gloaguen, E; Ahad, J M E; Malet, X; Aznar, J C; Malo, M |
| Source | Marine and Petroleum Geology vol. 100, 2018 p. 466-483, https://doi.org/10.1016/j.marpetgeo.2018.11.004  Open Access |
| Year | 2018 |
| Alt Series | Natural Resources Canada, Contribution Series 20180257 |
| Publisher | Elsevier BV |
| Document | serial |
| Lang. | English |
| Media | paper; on-line; digital |
| File format | pdf (Adobe® Reader®); docx (Microsoft® Word®) |
| Province | Quebec |
| NTS | 21E/12; 21E/13; 21E/14; 21L/03; 21L/04; 21L/05; 21L/06; 21L/11; 21L/12; 21L/13; 21L/14; 31G/01; 31G/08; 31G/09; 31G/16; 31H; 31I/01; 31I/02; 31I/03; 31I/04; 31I/05; 31I/06; 31I/07; 31I/08; 31I/09; 31I/10;
31I/11; 31I/15; 31I/16 |
| Area | St. Lawrence River; Saint-Edouard; Montreal |
| Lat/Long WENS | -74.5000 -71.0000 47.0000 45.0000 |
| Subjects | hydrogeology; fossil fuels; environmental geology; regional geology; structural geology; geophysics; engineering geology; geochemistry; groundwater; aquifers; groundwater resources; groundwater
pollution; petroleum resources; hydrocarbon recovery; gas; fluid migration; hydrocarbon migration; groundwater flow; bedrock geology; lithology; sedimentary rocks; shales; structural features; faults; faults, normal; faults, thrust; fractures;
exploration wells; observation wells; water wells; gas wells; hydraulic fracturing; groundwater regimes; hydrodynamics; geophysical surveys; seismic surveys, ground; seismic reflection surveys; field work; hydraulic analyses; groundwater
geochemistry; brine; propane; methane; isotopic studies; carbon isotopes; flow regimes; modelling; whole rock geochemistry; Utica Shale; St. Lawrence Lowlands; St. Lawrence Platform; Logan Line; Aston Fault; Chambly-Fortierville Syncline; Queenston
Group; Lorraine Group; Pontgravé Formation; Nicolet Formation; Sainte-Rosalie Group; Lotbinière Formation; Les Fonds Formation; Trenton Group; Black River Group; Chazy Group; Beekmantown Group; Potsdam Group; Appalachian Orogen; Grenville Orogen;
Riviere Jacques-Cartier Fault; Methodology; Regulations; Phanerozoic; Paleozoic; Ordovician |
| Illustrations | schematic cross-sections; location maps; geoscientific sketch maps; cross-sections; seismic profiles; profiles; models; bar graphs; graphs; time series; tables |
| Program | Environmental Geoscience |
| Released | 2018 11 09 |
| Abstract | Potential impacts of shale gas development on shallow aquifers has raised concerns, especially regarding groundwater contamination. The intermediate zone separating shallow aquifers from shale gas
reservoirs plays a critical role in aquifer vulnerability to fluid upflow, but the assessment of such vulnerability is challenging due to the general paucity of data in this intermediate zone. The ultimate goal of the project reported here was to
develop a holistic multi-geoscience methodology to assess potential impacts of unconventional hydrocarbon development on fresh-water aquifers related to upward migration through natural pathways. The study area is located in the St. Lawrence Lowlands
(southern Quebec, Canada), where limited oil and gas exploration and no shale gas production have taken place. A large set of data was collected over a ?500 km2 area near a horizontal shale gas exploration well completed and fracked into the Utica
Shale at a depth of ~~2 km. To investigate the intermediate zone integrity, this project integrated research results from multiple sources in order to obtain a better understanding of the system hydrodynamics, including geology, hydrogeology, deep
and shallow geophysics, soil, rock and groundwater geochemistry, and geomechanics. The combined interpretation of the multidisciplinary dataset demonstrates that there is no evidence of, and a very limited potential for, upward fluid migration from
the Utica Shale reservoir to the shallow aquifer. Microbial and thermogenic methane in groundwater of this region appear to come from the shallow, organic-rich, fractured sedimentary rocks making up the regional aquifer. Nonetheless, diluted brines
present in a few shallow wells close to and downstream of a normal fault revealed that some upward groundwater migration occurs, but only over a few hundred meters from the surface based on the isotopic signature of methane. The methodology developed
should help support regulations related to shale gas development aiming to protect groundwater. |
| Summary | (Plain Language Summary, not published)
Potential impacts of shale gas development on shallow aquifers has raised concerns. The intermediate zone separating shallow aquifers from shale gas
reservoirs plays a critical role relative to aquifer vulnerability to fluid upflow, yet very few data are available for this zone. The ultimate goal of the project reported here was to develop a holistic multi-geoscience methodology to assess
potential impacts of unconventional hydrocarbon development on aquifers related to upward migration. The study area is located in the St. Lawrence Lowlands (Quebec), where limited oil and gas exploration and no shale gas production have taken place.
To investigate the intermediate zone integrity, this project integrated data from multiple sources. One of the conclusions is that there is no evidence of upward fluid migration from the Utica Shale reservoir to the surface. This work should help
support regulations related to shale gas development aiming to protect groundwater. |
| GEOSCAN ID | 312991 |
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