FINAL REPORT Assessment of geothermal resources in onshore Nova Scotia Setting the stage, demonstrating value, and identifying next steps Félix-Antoine Comeau1 Stephan Séjourné 2 Jasmin Raymond1 1Institut national de la recherche scientifique (INRS), Centre Eau Terre Environnement 2Enki GeoSolutions inc. Rapport de recherche R2002 Prepared for the account of: Offshore Energy Research Association (OERA) December 1st, 2020 © INRS, Centre - Eau Terre Environnement, 2020 Tous droits réservés ISBN : 978-2-89146-939-5 (version électronique) Dépôt légal - Bibliothèque et Archives nationales du Québec, 2020 Dépôt légal - Bibliothèque et Archives Canada, 2020 Table of Contents ACKNOWLEDGEMENTS.................................................................................................................. 13 FOREWORD ......................................................................................................................................... 15 EXECUTIVE SUMMARY ................................................................................................................... 17 1. OVERVIEW OF THE GEOTHERMAL RESOURCE TYPES ............................................... 21 1.1 Geothermal systems ............................................................................................................... 21 1.1.1 Magmatic .......................................................................................................................... 25 1.1.2 Sedimentary basins ........................................................................................................... 25 1.1.3 Enhanced geothermal systems (EGS) and deep Borehole heat exchanger (BHE) ........... 26 1.2 Geothermal resource types .................................................................................................... 28 1.2.1 Electricity generation (> 80 °C, > 3 km) ........................................................................... 29 1.2.2 Direct-use of heat from mid-depth aquifers (< 80 °C, < 4 km) ........................................ 29 1.2.3 Heating and cooling from abandoned mines..................................................................... 32 1.3 References ............................................................................................................................... 33 2. EXAMPLES OF INDUSTRIAL DEVELOPMENTS AROUND THE WORLD ................... 37 2.1 Electricity generation from deep sedimentary aquifers ..................................................... 38 2.1.1 Germany ............................................................................................................................ 38 2.1.2 Saskatchewan (Canada) .................................................................................................... 39 2.1.3 British Columbia (Canada) ............................................................................................... 41 2.2 Direct-use of heat from mid-depth sedimentary aquifers .................................................. 42 2.2.1 Germany ............................................................................................................................ 42 2.2.2 Netherlands ....................................................................................................................... 43 2.2.3 Denmark ............................................................................................................................ 45 2.2.4 France ................................................................................................................................ 45 2.2.5 United Kingdom ................................................................................................................ 45 2.3 Enhanced geothermal systems (EGS) and deep Borehole heat exchanger (BHE) ........... 46 2.3.1 France ................................................................................................................................ 48 2.3.2 Québec (Canada) ............................................................................................................... 49 2.4 Heating and cooling from abandoned mines ....................................................................... 50 2.4.1 Germany ............................................................................................................................ 50 2.4.2 Netherlands ....................................................................................................................... 50 2.4.3 Norway .............................................................................................................................. 51 2.4.4 Nova Scotia (Canada) ....................................................................................................... 51 2.4.5 Québec (Canada) ............................................................................................................... 51 2.4.6 Spain.................................................................................................................................. 52 2.4.7 United Kingdom ................................................................................................................ 52 2.4.8 USA ................................................................................................................................... 52 2.4.9 Summary ........................................................................................................................... 52 2.5 References ............................................................................................................................... 53 3. GEOLOGY OVERVIEW OF NOVA SCOTIA ......................................................................... 57 3.1 General setting ........................................................................................................................ 57 3.2 Avalon Zone ............................................................................................................................ 58 3.3 Meguma terrane ..................................................................................................................... 58 3.4 Devonian intrusives ................................................................................................................ 58 3.5 Maritimes Basin ...................................................................................................................... 58 3.6 Fundy Basin ............................................................................................................................ 59 3.7 References ............................................................................................................................... 62 4. COMPILATION OF GEOTHERMAL DATA IN NOVA SCOTIA ........................................ 63 4.1 Previous studies ...................................................................................................................... 63 4.1.1 Geothermal data ................................................................................................................ 63 4.1.2 Abandoned mines .............................................................................................................. 63 4.1.3 Abandoned coal mines applications .................................................................................. 63 4.1.4 OERA’s assessment program ............................................................................................ 63 4.2 Surface temperatures ............................................................................................................. 64 4.3 Underground temperatures ................................................................................................... 64 4.3.1 From published sources .................................................................................................... 64 4.3.2 From petroleum well data ................................................................................................. 66 4.3.3 Level of confidence ........................................................................................................... 67 4.4 Volumes of abandoned mines ................................................................................................ 68 4.5 References ............................................................................................................................... 70 5. METHODOLOGY OF THE GEOTHERMAL POTENTIAL EVALUATION ..................... 73 5.1 Sedimentary basins................................................................................................................. 73 5.1.1. Underground temperatures ................................................................................................ 73 5.1.2 Geothermal gradients ........................................................................................................ 77 5.1.3 Sedimentary aquifers......................................................................................................... 78 5.1.4 Ranking of the geothermal potential ................................................................................. 81 5.2 Meguma terrane and the Devonian intrusives..................................................................... 84 5.3 Abandoned mines ................................................................................................................... 85 5.3.1 Assumptions .....................................................................................................................