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.

中文翻译：

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英格兰北部的深层地热能：来自 3D 有限温差建模的见解

摘要 英国许多最广泛使用的深层地热资源图是通过围绕稀疏分布且通常不可靠的数据点绘制等高线绘制的。因此，我们提出了一种基于 MATLAB 的 3D 有限差分温度建模方法，它提供了一种方法来生成这些地图的更精确和地质真实的版本。我们在英格兰北部的案例研究区代表了一个沉积盆地和辐射热花岗岩体都包含潜在地热资源的地区。我们将我们的 3D 模型划分为地质单元，然后分配给单独的热属性。假设传导传热和稳态和固定边界条件，我们计算 3D 区域地下温度。由于我们的热性能平均技术，相对于类似的有限元方法，我们的地质模型的分辨率几乎没有受到影响。在我们案例研究区域的中心部分，一个 1 公里深度的预测“热点”对应于花岗岩北奔宁岩基。其他浅层热点对应于绝热沉积岩单元和包含这些单元的地质结构。预测热流密度图突出显示与浅层导电基底岩和发热花岗岩体相关的加速表面热流区域。我们预测的地下温度与测得的平衡钻孔温度具有广泛的相似性。不准确可能与涉及断层系统的对流传热或与地质模型相关的输入变量有关。相对于预先存在的等高线图，我们的预测地下温度和热流密度图更加准确和地质现实。这里介绍的方法是了解地下温度分布和地热潜力控制的有用工具。