Geothermal Characterization of the St. Lawrence Lowlands Sedimentary Basin, Québec, Canada

Long-Term Temperature Evaluation of a Ground-Coupled Heat Pump System Subject to Groundwater Flow

“…Thermal conductivity of gabbro was measured in another case study and ranged between 1.65 and 2.29 W m −1 K −1 [45], which is consistent with our results. Shale samples have an average thermal conductivity ranging between 2.4 and 2.9 W m −1 K −1 (Table 2), which is in agreement with a value of 2.8 W m −1 K −1 measured for other samples of similar lithology in the St. Lawrence lowlands [10,12,44,46]. The calcarenite sample has the highest thermal conductivity among all the samples collected in the quarry, with a value of 3.5 W m −1 K −1 .…”

“…The Carignan-Salières elementary school is located on the south shore of the St. Lawrence River near Montreal ( Figure 1) and was built above the Nicolet Formation. This sedimentary rock formation belongs to the Loraine Group, known to have a thermal conductivity on the order of 3 W m −1 K −1 [12][13][14], and is part of the St. Lawrence Lowlands sedimentary basin [15]. From a structural perspective, the St. Lawrence Lowlands are characterized by a series of normal faults extending from the southwest to the northeast, and which dip toward the southeast [16,17].…”

“…The thermal conductivity assessments were made with two different methods: (1) a needle probe for hard rocks [12,[28][29][30] and (2) the modified transient plane source (MTPS) method for friable rocks [30][31][32]. The KD2 Pro unit [33], part of a standardized method under the ASTM D5334 norm, was used for the needle probe analysis with gabbro samples, while the C-therm heating plate following the ASTM D7984 norm was used for the MTPS analysis with shales and calcarenites [34].…”

“…The bottom surface was set impermeable and an annual net recharge of 100 mm y −1 was imposed at the top surface [23]. The initial ground temperature was assigned to each layer according to the geothermal gradient of the area (Figure 4), which is equal to 23.1 • C km −1 [12]. A fixed temperature boundary condition was used at the top of the model, while a constant heat flux was imposed at the bottom of the model in order to represent the Earth's heat flux in the St. Lawrence lowlands, which is assumed equal to 35 mW m −1 [43].…”

Thermophysical properties of surficial rocks: a tool to characterize geothermal resources of remote northern regions

“…Assuming a linear growth of this market, more than 180 000 units might have been installed by 2019. Deep geothermal resources have been the target of recent research (e.g., Bédard et al 2018;Ferguson and Grasby 2014;Grasby et al 2012;Hofmann et al 2014;Majorowicz and Grasby 2010;Minea 2012, 2015a;Majorowicz and Moore 2014;Nasr et al 2018), but no geothermal power plant is yet producing electricity.…”