Alternative (unconventional) deep geothermal designs are needed to provide a secure and efficient geothermal energy supply. An in-depth sensitivity analysis was investigated considering a deep borehole closed-loop heat exchanger (DBHE) to overcome the current limitations of deep EGS. A T2Well/EOS1 model previously calibrated on an experimental DBHE in Hawaii was adapted to the current NWG 55-29 well at the Newberry volcano site in Central Oregon. A sensitivity analysis was carried out, including parameters such as the working fluid mass flow rate, the casing and cement thermal properties, and the wellbore radii dimensions. The results conclude the highest energy flow rate to be 1.5 MW, after an annulus radii increase and an imposed mass flow rate of 5 kg/s. At 3 kg/s, the DBHE yielded an energy flow rate a factor of 3.5 lower than the NWG 55-29 conventional design. Despite this loss, the sensitivity analysis allows an assessment of the key thermodynamics within the wellbore and provides a valuable insight into how heat is lost/gained throughout the system. This analysis was performed under the assumption of subcritical conditions, and could aid the development of unconventional designs within future EGS work like the Newberry Deep Drilling Project (NDDP). Requirements for further software development are briefly discussed, which would facilitate the modelling of unconventional geothermal wells in supercritical systems to support EGS projects that could extend to deeper depths.

中文翻译：

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模拟非常规闭环深孔换热器（DBHE）：Newberry火山环境下的敏感性分析

需要替代性（非常规）深层地热设计以提供安全有效的地热能源供应。考虑到深孔闭环热交换器（DBHE），以克服深层EGS的当前局限性，进行了深入的灵敏度分析。先前在夏威夷的一个实验性DBHE上校准的T2Well / EOS1模型已适应俄勒冈中部Newberry火山现场的当前NWG 55-29井。进行了敏感性分析，包括诸如工作流体质量流速，套管和水泥的热性能以及井眼半径尺寸之类的参数。结果表明，在增加圆环半径和施加5 kg / s的质量流率之后，最高能量流率为1.5 MW。在3 kg / s的速度下，DBHE产生的能量流率为系数3。比NWG 55-29的常规设计低5英寸。尽管存在这种损失，但灵敏度分析仍可以评估井眼内的关键热力学，并提供有关整个系统如何损失/获取热量的宝贵见解。该分析是在亚临界条件下进行的，并且可以在诸如Newberry Deep Drilling Project（NDDP）等未来的EGS工作中帮助开发非常规设计。简要讨论了进一步软件开发的需求，这将有助于在超临界系统中对非常规地热井进行建模，以支持可能扩展到更深深度的EGS项目。敏感性分析可以评估井眼内的关键热力学，并提供有关整个系统如何损失/获取热量的宝贵见解。该分析是在亚临界条件下进行的，并且可以在诸如Newberry Deep Drilling Project（NDDP）等未来的EGS工作中帮助开发非常规设计。简要讨论了进一步软件开发的需求，这将有助于在超临界系统中对非常规地热井进行建模，以支持可能扩展到更深深度的EGS项目。敏感性分析可以评估井眼内的关键热力学，并提供有关整个系统如何损失/获取热量的宝贵见解。该分析是在亚临界条件下进行的，并且可以在诸如Newberry Deep Drilling Project（NDDP）等未来的EGS工作中帮助开发非常规设计。简要讨论了进一步软件开发的需求，这将有助于在超临界系统中对非常规地热井进行建模，以支持可能扩展到更深深度的EGS项目。