Lifetime optimisation of multiple deep closed-loop geothermal wells

多口深闭环地热井寿命优化

• 批准号: 2890095
• 金额: --
• 依托单位: Brunel University London
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2023
• 资助国家: 英国
• 起止时间: 2023 至 无数据
• 项目状态: 未结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-2890095
• 关键词: Lifetime; optimisation; multiple; deep; closed

Worldwide interest in geothermal energy is increasing as part of the solution mix in the prevailing energy and environmental crisis. Geothermal energy has a high capacity factor compared to solar and wind, hence being able to provide a predictable 24/7 supply of thermal energy that can be used to meet the base load in direct heat to heat applications or produce electrical power in conjunction with, for example, Organic Rankine Cycle plants. In addition, the geothermal footprint (m2/energy produced) is significantly smaller than that required by wind and solar installations making it a more attractive option both in terms of land use and social acceptability. Closed-loop geothermal systems as proposed here have the benefit of being available/installed anywhere and remove the exploration risks associated with open loop systems. In such systems the fluid is contained in coaxial heat exchangers hence, removing any environmental/societal concerns associated with water extraction and injection (fracking). Recently, the option and financial viability of using geothermal energy has been improved in line with the need to utilise abandoned oil and gas well, in addition to the plans for new ones.A single geothermal well has a radial area of influence for the transfer of thermal energy between the rock formation and the well bore. This is affected by the thermal diffusivity and conductivity of the geology and the amount of energy extracted. Over time, heat extraction leads to a reduced thermal output of a well. Therefore, multi-well developments as the ones proposed to be studied in the first part of this PhD programme can aid in thermally recharging wells using intermittent full load hours (variable heat flux and transient heat conduction) or switching between wells to allow for the original formation (to the extent of the radius of influence of the well) to recuperate heat at the well bore. One recurrent issue with geothermal funding is the upfront cost associated with new bore holes. However, geothermal energy offers a lower cost of energy (LCOE). Increasing the overall geothermal plant lifetime for a given site/application by using multiple wells will improve the LCOE, making geothermal an even more attractive option in the drive to net-zero.Machine learning can aid in decision-making and problem-solving for optimisation and control processes without human interference. In the second part of the work, the research programme will include the development of a deep learning optimisation framework to control geothermal production and to determine optimum intermittency, working flow rates and targeted return fluid temperatures for increased lifetime and production, while also investigating the effects on thermal degradation due to different well architectures and geologies.

全世界对地热能源的兴趣日益增加，这是解决当前能源和环境危机的一种综合办法。与太阳能和风能相比，地热能具有高容量系数，因此能够提供可预测的24/7热能供应，可用于满足直接加热应用中的基本负荷或与例如有机朗肯循环工厂结合产生电力。此外，地热足迹（平方米/产生的能源）远远小于风能和太阳能装置所需的足迹，使其在土地使用和社会接受度方面成为更有吸引力的选择。这里提出的闭环地热系统具有可在任何地方使用/安装的优点，并消除了与开环系统相关的勘探风险。在这种系统中，流体包含在同轴热交换器中，因此消除了与水提取和注入（水力压裂）相关的任何环境/社会问题。近年来，随着废弃油气井的利用以及新井的规划，地热能利用的选择和经济可行性都得到了提高。单个地热井在岩层和井筒之间具有热能传递的径向影响区域。这受到地质的热扩散率和传导率以及提取的能量的影响。随着时间的推移，热提取导致井的热输出减少。因此，在本博士课程的第一部分中拟研究的多井开发可以帮助使用间歇性满负荷小时（可变热通量和瞬态热传导）或威尔斯之间的切换对威尔斯进行热再充电，以允许原始地层（在井的影响半径范围内）在井筒中回收热量。地热资金的一个经常性问题是与新钻孔相关的前期成本。然而，地热能提供较低的能源成本（LCOE）。通过使用多口威尔斯井来增加给定场地/应用的地热发电厂的整体寿命将提高LCOE，使地热发电成为实现净零发电的更具吸引力的选择。机器学习可以帮助决策和解决问题，从而在没有人为干扰的情况下实现优化和控制过程。在工作的第二部分，研究计划将包括开发一个深度学习优化框架，以控制地热生产，并确定最佳的渗透率，工作流量和目标返回流体温度，以增加寿命和产量，同时还调查由于不同的井结构和地质对热降解的影响。