Deep geothermal energy in northern England: Insights from 3D finite difference temperature modelling

Howell, L., Brown, C. S. and Egan, S. S. (2021) Deep geothermal energy in northern England: Insights from 3D finite difference temperature modelling. Computers and Geosciences, 147, 104661. (doi: 10.1016/j.cageo.2020.104661)

Abstract

Many of the most widely used deep geothermal resource maps for the UK are produced by contouring around sparsely distributed and often unreliable data points. We thus present a MATLAB-based 3D finite difference temperature modelling methodology, which provides a means for producing more resolute and geologically realistic versions of these maps. Our case study area in northern England represents an area where both sedimentary basins and radiothermal granite bodies comprise potential geothermal resources. We divide our 3D model into geological units, which are then assigned separate thermal properties. Assuming conductive heat transfer and steady-state and fixed boundary conditions, we calculate 3D regional subsurface temperature. Due to our averaging technique for thermal properties, the resolution of our geological model is scarcely compromised with respect to similar finite element methods. One predicted ‘hot spot’ at 1 km depth in the central part of our case study area corresponds with the granitic North Pennine Batholith. Other shallow hot spots correspond with thermally insulating sedimentary rock units and geological structures that incorporate these units. Predictive heat flow density maps highlight areas with accelerated surface heat flow associated with shallow conductive basement rock and heat producing granite bodies. Our predicted subsurface temperatures show broad similarities with measured equilibrium borehole temperatures. Inaccuracies may relate to convective heat transfer involving fault systems, or input variables relating to the geological model. Our predictive subsurface temperature and heat flow density maps are more resolute and geologically realistic relative to pre-existing contoured maps. The method presented here represents a useful tool for understanding controls on subsurface temperature distribution and geothermal potential.

• Item Type: Articles
• Additional Information: This manuscript contains work conducted during a PhD study undertaken as part of the Natural Environment Research Council (NERC) Centre for Doctoral Training (CDT) in Oil & Gas [grant number: NEM00578X/1].
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Brown, Dr Christopher
• Authors: Howell, L., Brown, C. S., and Egan, S. S.
• Subjects: Q Science > QE Geology
• College/School: College of Science and Engineering > School of Engineering > Systems Power and Energy
• Journal Name: Computers and Geosciences
• Publisher: Elsevier
• ISSN: 0098-3004
• ISSN (Online): 1873-7803
• Published Online: 24 November 2020
• Copyright Holders: Copyright © 2020 Elsevier Ltd.
• First Published: First published in Computers and Geosciences 147:104661
• Publisher Policy: Reproduced in accordance with the publisher copyright policy