| Title | Assessing groundwater vulnerability to shale gas activities in the Sussex area, southern New Brunswick / Évaluation de la vulnérabilité des aquifères à l'exploitation du gaz de shale dans la région de
Sussex, dans le sud du Nouveau-Brunswick |
| Download | Download (whole publication) |
| |
| Licence | Please note the adoption of the Open Government Licence - Canada
supersedes any previous licences. |
| Author | Rivard, C |
| Source | Public presentations of May 21st, 2019: Environmental Geoscience Program, current status of research projects (phase 2014-2019); by Jacob, N; Parsons, M; Rivard, C; Savard, M M; Larmagnat, S; Outridge, P M; White, D; Kao, H; Lintern, G; Geological Survey of Canada, Scientific Presentation 104, 2019 p. 19-34, https://doi.org/10.4095/314919  Open Access |
| Year | 2019 |
| Publisher | Natural Resources Canada |
| Document | serial |
| Lang. | English; French |
| Media | on-line; digital |
| Related | This publication is contained in Public presentations of May
21st, 2019: Environmental Geoscience Program, current status of research projects (phase 2014-2019) |
| File format | pdf (Adobe® Reader®) |
| Province | New Brunswick |
| NTS | 21H/10; 21H/11; 21H/12; 21H/13; 21H/14; 21H/15; 21I/02; 21I/03; 21I/04 |
| Area | Sussex |
| Lat/Long WENS | -65.5842 -64.9228 46.0244 45.5872 |
| Subjects | environmental geology; hydrogeology; geochemistry; fossil fuels; geophysics; structural geology; Nature and Environment; Science and Technology; Government and Politics; Economics and Industry;
environmental studies; environmental impacts; groundwater resources; aquifers; groundwater pollution; groundwater geochemistry; water quality; flow regimes; petroleum resources; petroleum industry; hydrocarbons; gas; methane; hydrocarbon recovery;
hydrocarbon migration; flow regimes; hydraulic fracturing; bedrock geology; structural features; fractures; lithology; sedimentary rocks; shales; sandstones; evaporites; observation wells; reservoir rocks; field work; structural interpretations;
boreholes; geophysical logging; organic geochemistry; hydrocarbon maturation; modelling; Environmental Geoscience Program (EGP); McCully Gas Field; Elgin Gas Field; Environmental impact assessment; environmental baseline studies; monitoring;
Phanerozoic; Paleozoic; Carboniferous |
| Illustrations | location maps; schematic cross-sections; cross-sections; photographs; models; geophysical logs; plots; geoscientific sketch maps; bar graphs |
| Program | Environmental
Geoscience Program Management |
| Released | 2019 10 10 |
| Abstract | A project studying potential hydrocarbon migration through natural pathways or fracking-induced fractures from deep (~2 km) Carboniferous shale or tight sand units to shallow aquifers was initiated in
2015 in the Sussex area, southern New Brunswick. The study area includes the McCully gas field that has been in production since 2001 and the Elgin field that is investigated for its condensate potential. Because the intermediate zone (IZ) located
between shallow aquifers and units targeted for hydrocarbon production is poorly characterized, this project relies on the integration of data from different earth science disciplines, including geology, geophysics, geomechanics, hydrogeology and
water and rock geochemistry. Fieldwork in 2018-2019 included the drilling of two observation wells, borehole geophysics, and groundwater monitoring.
Data collected during this 4-year project and their interpretation provided no evidence for the
presence of large-scale connections between gas reservoirs and shallow aquifers in this study area. On the contrary, the IZ seems to provide an efficient barrier protecting the shallow aquifer from the potential upward migration of fluids originating
from deep hydrocarbon reservoirs. This conclusion integrates the interpretations derived from the geomechanical study, from the geophysical and geological analyses of the structural context and from the geochemical baseline study. Although
large-scale upward fluid migration is considered very unlikely, evidence of some upward migration over a few hundred meters was found based on old, evolved groundwater observed in two of the shallow (50 m) observation wells. This water indicated a
contribution from evaporites from a relatively shallow salt structure (~250-300 m), whose chemical components are assumed to have been transferred to the active groundwater flow zone by diffusion. Also, regular monitoring of several shallow wells
helped ascertain the source of methane in groundwater when individual samples provided ambiguous results. |
| Summary | (Plain Language Summary, not published)
This scientific document is a wrap up of the research done in the Environmental Geoscience Program from 2014 to 2019. This document explain the science
behind the program over the past 5 years covering a range of state of the art science in critical metal deposits, geoscience tools, shale gas and groundwater, oil sands, fluid in carbonates, mercury, geological storage of carbon, induced seismicity
and dredge disposal. All the sciences done under this program contribute to provincial regulations as well as environmental assessments to ensure the safety and security of Canadians and to their environment. |
| GEOSCAN ID | 314919 |
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