The Impact of Subsurface Heterogeneity on the Performance of Aquifer Thermal Energy Storage (ATES) Systems

全球能源需求正在稳步上升，预计未来15年将增长45%。从长远来看，可持续能源有望将经济增长与增加社会公平联系起来，同时根据联合国可持续发展目标保护自然资源。在这方面，地热能是实现这一目标的潜在关键支柱之一。在过去的几十年里，浅层地热能系统的应用一直在增加，2015年在欧盟各地安装了超过170万套。用于地热装置的通常应用的设计之一是开环系统，其包括安装在含水层系统/地下水体中的抽取和回注威尔斯井，以从含水层提取热量或将热量注入/储存到含水层中。开环地热装置的一种特殊设计支持含水层热能储存（ATES）系统，该系统允许在地下季节性储存废热，以供后续使用，以满足供暖需求。该系统的效率取决于水井设施的生产力以及适当的含水层特性（包括含水层的含水量）。含水层渗透性和孔隙度以及热特性）。计划中的研究项目将调查地下异质性对ATES装置性能的影响。地下非均质性可能与沉积含水层或不连续面（如裂缝、火成岩侵入体或断层）的沉积特征有关，并可能影响寄主岩石的水力和热力性质。这些不均匀性可能会影响含水层单元内的地下水流动状况，并影响含水层储存和传导热量的能力。这反过来又可能最终影响ATES安装的整体效率和可持续性。该项目将使用三叠纪舍伍德砂岩含水层作为案例研究的例子。舍伍德砂岩含水层是横跨英格兰中部和北方爱尔兰的重要区域含水层，含有深度大于100 m的深层饮用地下水。这项研究将结合联合收割机的全面实地实验，利用现有的钻孔装置在女王大学贝尔法斯特与数值模拟研究。这项研究将通过完成一系列主动钻孔地球物理测量、水力钻孔试验，结合联合收割机对含水层系统的基线特征进行分析，并利用光纤分布式温度传感对实验性热注入试验进行长期监测。收集的监测数据将被纳入数值热传输模型，以评估现场规模的地下特性，以更好地了解含水层异质性对系统性能的影响。

Global energy needs are steadily rising with a predicted increase of 45% within the next 15 years. In the long-term, sustainable energy is hoped to connect economic growth to increased social equity while preserving natural resources in line with the UN sustainable development goals. In this context, geothermal energy present one of the potential key pillars to achieve this goal. The application of shallow geothermal energy systems has been increasing over the past decades with >1.7 million units installed across the EU in 2015. One of the commonly applied designs for geothermal installations are open loop systems consisting of abstraction and re-injection wells installed in the aquifer system/groundwater body to extract heat from or to inject/store heat into the aquifer. A particular design of open loop geothermal installations support Aquifer Thermal Energy Storage (ATES) systems which allow the seasonal storage of waste heat in the subsurface for subsequent use to meet heating demands. The efficiency of the system relies on the productivity of the well installations as well as suitable aquifer properties (incl. aquifer permeability & porosity and thermal properties). The planned research project will investigate the impact of subsurface heterogeneity on the performance of ATES installations. Subsurface heterogeneities may be associated with depositional features of sedimentary aquifers or discontinuities such as fractures, igneous intrusions or faults and may affect hydraulic and thermal properties of the host rock. These heterogeneities may affect the groundwater flow regime within the aquifer unit and impact on ability of the aquifer to store and conduct heat. This in turn may ultimately affect the overall efficiency and sustainability of the ATES installation. The project will use the Triassic Sherwood Sandstone Aquifer as a case study example. The Sherwood Sandstone Aquifer is an important regional aquifer across central England and Northern Ireland that hosts deep potable groundwater to depth >100m. The study will combine full-scale field experiments utilising existing borehole installations at Queen's University Belfast with numerical modelling studies. The study will combine the baseline characterisation of the aquifer system by completing a series of active borehole geophysical measurements, hydraulic borehole tests, with the long-term monitoring of experimental thermal injection tests using fibre optic distributed temperature sensing. Collected monitoring data will be integrated into numerical heat transport models to evaluate field-scale subsurface properties to better understand the impact of aquifer heterogeneity on system performance.