Collaborative Research: Development and fabrication of a high-temperature borehole fluid sampler to characterize seawater-basalt reactions and the thermal limits of life on Earth

合作研究：开发和制造高温钻孔流体采样器，以表征海水-玄武岩反应和地球上生命的热极限

• 批准号: 1829670
• 负责人: Christopher Kitts
• 金额: $ 27.24万
• 依托单位: Santa Clara University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-08-15 至 2022-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1829670&HistoricalAwards=false
• 关键词: Collaborative; Research; Development; fabrication; temperature

Five decades of scientific ocean drilling have created more than 113-cased boreholes in the ocean. Such legacy boreholes have been drilled into a range of seafloor geologic settings and many of these boreholes are deep enough that natural geothermal gradients have warmed the boreholes to temperatures in the range (60-200 degrees C). Within this temperature range reactions pathways between seawater and basalt change, affecting how the basaltic crust ages through the dissolution of primary minerals and the precipitation of different minerals as veins, for example. This combination of dissolution and precipitation changes the characteristics of the ocean crust that ultimately affects how the crust is subducted and the potential for large destructive earthquakes. This temperature range also spans the thermal limits of microbial life, based on experiments (122 degrees C), theoretical calculations (150 degrees C), and anecdotal evidence (180 degrees C). However the scientific drilling community currently lacks the ability to collect such warm pristine borehole fluids because electronics fail at such temperatures. This project will solve this sampling problem by first testing shape memory alloys, which are metal alloys that can change their shape and length at a specific temperature that is a function of the alloy composition and fabrication process. Then a water sampling system will be developed that utilizes the properties of shape memory alloys to trigger the collection of boreholes fluids. The first deployment of the newly fabricated system will occur in July 2019 when the scientific drilling program re-enters a legacy borehole that is ~200 degrees C at the base of the hole. The broader impacts of this project will provide the scientific community with a new sampling system for collecting borehole fluids at elevated temperatures. Such a sampling system is not limited to oceanic boreholes, but could be used within the thousands of existing continental boreholes. This new high temperature fluid sampling system will allow the community to explore new directions in understanding hydrothermal processes. Hydrothermal processes and the thermal limits of life are exciting topics that engage the public. More specifically the proposed work will include the development of a hands-on module for a week-long summer day camp (ssrovcamp.org) for rising 3-5th and 6-9th grade students and students involved in the undergraduate marine education program at Santa Clara University. Combined, over 300 students were engaged in one of these two programs in 2018.The crux of this project is to design and fabricate a fluid sampling system for high temperature 60-200 degrees C borehole applications in oceanic and continental settings. The project will build on a Provisional Patent to design and fabricate standard titanium syringe-like fluid capture systems that are triggered by a novel mechanism. This mechanism will use shape memory alloys, given that such alloys change shape at a particular temperature. The sampling system will be modular in design to allow a suite of samples to be collected on a single lowering, each sampler collecting fluid at a specific temperature depending on the particular shape memory alloy that is used in that sampler. This system will be designed to be deployable from oceanic drilling vessels, continental drilling rigs, and submersibles/remotely operated vehicles (ROVs).This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

五年来的科学海洋钻探已经在海洋中打出了超过 113 个钻孔。此类传统钻孔已钻入一系列海底地质环境中，其中许多钻孔的深度足够深，自然地温梯度已将钻孔加热至该范围内的温度（60-200 摄氏度）。在此温度范围内，海水和玄武岩之间的反应路径会发生变化，从而影响玄武岩地壳如何通过原生矿物的溶解和不同矿物（例如矿脉）的沉淀而老化。这种溶解和降水的结合改变了洋壳的特征，最终影响了地壳的俯冲方式以及发生大型破坏性地震的可能性。根据实验（122 摄氏度）、理论计算（150 摄氏度）和轶事证据（180 摄氏度），该温度范围还跨越了微生物生命的热极限。然而，科学钻井界目前缺乏收集如此温暖的原始钻孔流体的能力，因为电子设备在这样的温度下会失效。该项目将通过首先测试形状记忆合金来解决这个采样问题，形状记忆合金是可以在特定温度下改变其形状和长度的金属合金，而特定温度是合金成分和制造工艺的函数。然后将开发一种水采样系统，利用形状记忆合金的特性来触发钻孔流体的收集。新制造的系统将于 2019 年 7 月首次部署，届时科学钻探计划将重新进入孔底温度约为 200 摄氏度的遗留钻孔。该项目的更广泛影响将为科学界提供一种新的采样系统，用于在高温下收集井眼流体。这种采样系统不仅限于海洋钻孔，还可以在数千个现有的大陆钻孔内使用。这种新的高温流体采样系统将使社区能够探索了解热液过程的新方向。热液过程和生命的热极限是公众关注的令人兴奋的话题。更具体地说，拟议的工作将包括为 3-5 年级和 6-9 年级的新生以及参与圣塔大学本科海洋教育项目的学生开发为期一周的夏令营实践模块 (ssrovcamp.org)克拉拉大学。 2018 年，总共有 300 多名学生参与了这两个项目之一。该项目的关键是设计和制造用于海洋和大陆环境中 60-200 摄氏度高温钻孔应用的流体采样系统。该项目将建立在一项临时专利的基础上，设计和制造由一种新颖机制触发的标准钛注射器式流体捕获系统。该机制将使用形状记忆合金，因为这种合金在特定温度下会改变形状。采样系统采用模块化设计，允许在一次下降中收集一套样品，每个采样器根据该采样器中使用的特定形状记忆合金在特定温度下收集流体。该系统将设计为可在海洋钻井船、大陆钻井平台和潜水器/遥控潜水器 (ROV) 上进行部署。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力优势和更广泛的影响进行评估，被认为值得支持审查标准。

项目成果

A new high-temperature borehole fluid sampler: the Multi-Temperature Fluid Sampler

新型高温钻孔流体采样器：多温流体采样器

• DOI: 10.5194/sd-28-43-2020
• 发表时间: 2020
• 期刊: Scientific Drilling
• 影响因子: 1.2
• 作者: Wheat, C. Geoffrey;Kitts, Christopher;Webb, Camden;Stolzman, Rachel;McGuire, Ann;Fournier, Trevor;Pettigrew, Thomas;Jannasch, Hans
• 通讯作者: Jannasch, Hans