Geothermal Power Generated from UK Granites (GWatt)

脱碳发电对英国来说是一项挑战，要求到2050年将温室气体排放量比1990年的水平减少80%。无碳、可再生能源很有吸引力，但风能和太阳能发电是间歇性的。相比之下，地热发电一直都是可用的(即“基本负荷”)。在英国，这可以通过工程地热系统(EGS)来开发，通过深井(4公里或更长)从深处获取非常热水，并用来驱动涡轮机。开创性的研究表明，深层的可渗透岩石(流体可以流经的岩石)通常与天然裂缝系统有关。然而，英国地下热资源的开发一直受到以下因素的阻碍：1)关于裂解热岩内渗透性和流体/热流的知识差距；2)人们认为与钻井问题或深井有限的流体流动相关的不确定性太高，无法获得潜在的经济回报。该项目名为英国花岗岩地热发电(GWatt)，旨在通过以下方式解决这些吸收EGS的障碍：-增加对花岗岩中深层裂隙控制流体流动所需的地质条件的了解。-对地热储藏库的热源和可持续性有一个定量的了解。-根据成熟的石油和天然气不确定性量化和优化方法，建立健全的地质风险评估，以期减少感知的风险。-将现场研究的综合结果应用于其他花岗岩的新地热勘探模型，特别是在英格兰西南部的花岗岩。GWatt的一个特别优势是与正在开发的联合唐斯深层地热发电(UDDGP)项目的联系，该项目是康沃尔Carnmenellis花岗岩中的GB 18米2钻孔EGS。这将提供独特的资源：井下流体、岩石样本、地球物理记录、流动数据和地震数据。GWatt将最大限度地利用这些数据的科学潜力，并进行创新的进一步分析和解释，将特定地点的观测与区域研究和最先进的不确定性量化相结合，以应对与英格兰西南部EGS开发相关的挑战。英国其他结晶基岩显示出受裂缝控制的地下水流动，因此从GWatt学到的经验最终将有助于理解英国其他地区的深层地下。该项目财团由研究、商业和当地政府合作伙伴组成。英国地质调查局、埃克塞特大学坎伯恩矿业学院和赫里奥特·瓦特大学在深部地热资源评估、深部裂缝流体流动、岩石/流体相互作用、储层建模、英格兰西南部地质的详细知识和地质不确定性的量化方面提供免费技能。地热工程有限公司和地球科学有限公司正在开发UDDGP项目，并为英国地热项目提供丰富的经验。计算机建模集团有限公司将提供先进的热和流体流动建模软件。康沃尔和锡利岛地方企业伙伴关系和康沃尔理事会将促进面向当地人民和企业界的外联和传播活动。通过创建EGS联合供热和发电厂，惠及当地社区，这些工厂将成为可再生能源网络的重要枢纽，提供无碳供热和电力。这些热量可用于空间供暖、工业烘干、沐浴、温室供暖、养鱼场等，所有这些都将为当地创造就业机会。当地工业还将受益于英格兰西南部地区EGS的区域规模吸收，以及从深层地热卤水中提取金属的技术解决方案可能带来的矿产行业的复苏。

Decarbonising power generation is a challenge for the UK, requiring an 80% reduction in greenhouse gas emissions by 2050, relative to 1990 levels. Carbon-free, renewable sources are attractive, but wind and solar generation are intermittent. In contrast, geothermally generated electricity is available all the time (i.e. is 'base load'). In the UK this can be developed with Engineered Geothermal Systems (EGS) whereby very hot water is accessed from depth via deep boreholes (4km or more) and is used to drive a turbine. Pioneering research has shown that permeable rocks (those through which fluid can flow) at depth are often associated with natural fracture systems. However, exploitation of the UK underground thermal resource has been held back by; 1) knowledge gaps about permeability and fluid/heat flow within the fractured hot rocksand 2) a perception that the uncertainty associated with drilling problems or limited fluid flow from deep boreholes are too high for the potential financial reward. This project, Geothermal Power Generated from UK Granites (GWatt), seeks to address these barriers to uptake of EGS by:- Increasing knowledge of the geological conditions needed for deep fracture-controlled fluid flow within granitic rocks. - Developing a quantitative understanding of the heat resource and sustainability of the geothermal reservoir. - Constructing robust geological risk assessments based on well-established oil & gas uncertainty quantification and optimisation methods, with a view to reducing perceived risks. - Applying the integrated results of site-specific research to new geothermal exploration models for other granites, particularly those in SW England.A particular strength of GWatt is the link with the developing United Downs Deep Geothermal Power (UDDGP) project, an £18M, 2 borehole EGS in the Carnmenellis granite in Cornwall. This will provide a unique resource; downhole fluids, rock samples, geophysical logs, flow data and seismic data. GWatt will maximise the scientific potential from these data, and carry out innovative further analyses and interpretation, combining site-specific observations with regional studies and state-of-the-art uncertainty quantification, to address the challenges associated with EGS development within SW England. Other UK crystalline basement rocks show fracture-controlled groundwater flow, so the lessons learned from GWatt will ultimately benefit understanding of the rest of the UK deep subsurface.The project consortium comprises research, business and local government partners. The British Geological Survey, the University of Exeter Camborne School of Mines and Heriot Watt University provide complimentary skills in deep geothermal resource assessments, deep fracture fluid flow, rock/fluid interactions, reservoir modelling, detailed knowledge of the geology of SW England and the quantification of geological uncertainties. Geothermal Engineering Ltd. and Geoscience Ltd. are developing the UDDGP project and provide a wealth of experience delivering UK geothermal projects. Computer Modelling Group Ltd. will provide advanced heat and fluid flow modelling software. The Cornwall and Isles of Scilly Local Enterprise Partnership and Cornwall Council will facilitate outreach and dissemination activities, both to local people and the business community.Beneficiaries include local communities through the creation of EGS combined heat and power plants that will be important hubs for renewable energy networks, supplying carbon-free heat and power. The heat can be used for space heating, industrial drying, balneology, greenhouse heating, fish farms etc., all of which will generate local jobs. Local industry will also benefit from the regional scale uptake of EGS within SW England and a potential revival of the minerals industryarising from technological solutions to extracting metals from the deep geothermal brines.