Shallow and deep geothermal resources assessment in northern communities of Québec: preliminary results from Kuujjuaq M. M. Miranda (
[email protected]), N. Giordano (
[email protected]), I. Kanzari (
[email protected]), J. Raymond (
[email protected]), C. Dezayes (
[email protected])
Objectives
Renewable and affordable energy production is a key aspect for the development of Canadian northern communities. In these remote areas, heat and electricity are mostly obtained by burning fossil fuels incurring high economical and environmental costs. Implementing geothermal technologies would diversify their energy sources while decreasing CO2 emission. The project’s objectives are to determine the potential and viability of exploiting geothermal resources in the North of Québec, namely in the community of Kuujjuaq, by means of three main geothermal energy systems: 1) Underground Thermal Energy Storage, 2) Shallow Ground-Source Heat Pumps, 3) Deep Geothermal Systems – Enhanced Geothermal Systems (EGS) and deep borehole heat exchangers.
Rock and soil samples
λ water-saturated (W m-1 K-1)
In-situ thermal conductivity map of soil samples
ERT (Electrical Resistivity Tomography)
Comparison of thermal conductivities (λ) measured under in-situ and water-saturated conditions 2.5
1.5 1.0 0.5
Scale
0.0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 λ in-situ (W m-1 K-1)
A: alluvial deposits M: marine deposits R: Rocks T: till
Legend Glacial
Outcrops
Organic
Marine
Alluvial
2
Methodology ERT surveys were carried out in 4 different sites selected by Kativik Regional Governement (KRG) as the most compelling to aim at reducing fossil fuel dependency: these are drinking water facilities (2, 3) and greenhouses (4) for local fruit and vegetable growing. Wenner-Schlumberger and Dipole-Dipole configurations were adopted with 2-3 m spacing depending on the local setting.
2.0
0.0
Map of the quaternary sediments
Aims - Identification of bedrock depth - Definition of permafrost state
1. Calibration site 3
4
N paragneiss tonalite
Calibration site
granite
gabbro and diorite
W18
a-priori info
W19
sands/silts
GW flow 2
8 diorite
12 24 bedrock
Temperature logs Well 18
20 30 40 50 60
-1
0
0
1
T (°C) 2
10 20
0
0
Inferred geological section T (°C) 2
1
5 10 15
30
20
40
Greenhouses
25
50
30
70
60
80
70
40
90
80
45
100
90
50
35
N
Depth (m)
FAU-16-004 0 20 40 60 80 100
0
2
FAU-16-010
T (°C) 4 Depth (m)
10
1
Well 16
Depth (m)
0
0
T (°C) 2 Depth (m)
Depth (m)
Well 19
0
2
GH
20 40 60
Gravel pad anti-permafrost >1000 Ohm.m
Marine saturated sediments 100-700 Ohm.m
80
120
100
140
120
Fracture analysis in scanlines
0
T (°C) 4
Inferred geological section
Further work • Thermal and hydraulic properties analysis of rock samples – surface and drilled core; • Heat flow and temperature gradient estimations; • Fracture network characterization; • Borehole heat exchangers efficiency in permafrost; • Economic viability of geothermal energy systems
