Collaborative Research: Coupled Thermal-Hydrological-Mechanical-Chemical-Biological Experimental Facility at DUSEL Homestake

该项目将开发一个大型地下实验设施的初步设计和工作分解结构，以研究深部裂隙岩石中的热-水文-机械-化学-生物耦合过程。该实验将成为南达科他州霍姆斯特克矿拟议中的深部地下科学与工程实验室（DUSEL）的一部分。许多自然和工程地球系统涉及岩石中多种过程的耦合，这些过程在很大范围内变化。地球上最普遍的过程是什么？产生强耦合现象的地壳是流体（水、二氧化碳、碳氢化合物、岩浆）在应力作用下穿过破裂的加热岩石的流动。了解岩石在流体渗透下的反应性、可变形性、生命维持性和输运性的变化，在地质工程和地质科学的广泛研究中具有重要意义。尽管这种基本的重要性，相互作用仍然知之甚少。该项目将：(1)确定Homestake岩石的性质：地质、地球化学、机械、热、同位素和反应性。(2)对这些数据进行升级，以阐明输送机制（导电还是对流）、裂缝中的自然反应速率和微生物群落进化。(3)评估监测策略、原位探针和采样方法以及必要的测量。(4)选择评价耦合过程的候选场地。(5)建立工作分解结构。(6)建立耦合数值模型，以评估对岩体和最佳加热器配置、功率和监测井眼方向的潜在影响。这些实验的模型和见解将广泛适用于工程系统，例如增强型地热系统、二氧化碳封存和地下污染物输送。教育推广将包括参观设施和旅行的基准模型。演示实验。

This project will develop a preliminary design and work-breakdown-structure for a large-scale subsurface experimental facility to investigate coupled thermal-hydrological-mechanical-chemical-biological processes in fractured rock at depth. The experiment will be part of the proposed Deep Underground Science and Engineering Laboratory (DUSEL) in the Homestake Mine, South Dakota. Many natural and engineered earth systems involve coupling of multiple processes in rocks that vary across a wide range of scales. The most pervasive process in the Earth?s crust that gives rise to strongly coupled phenomena is the flow of fluids (water, CO2, hydrocarbons, magmas) through fractured heated rock under stress. Understanding changes in the reactivity, deformability, life-supporting and transport properties of rocks that fluids infiltrate is important in a broad range of geological engineering and geological science endeavors. Despite this fundamental importance, the interactions remain poorly understood.The project will: (1) Determine properties of Homestake rocks: geological, geochemical, mechanical, thermal, isotopic, and reactivity. (2) Upscale these data to elucidate transport mechanisms (conductive versus convective), natural reaction rates in fractures, and microbial community evolution. (3) Evaluate monitoring strategies, in-situ probes and sampling methods, and necessary measurements. (4) Select a candidate site for the evaluating coupled processes. (5) Develop a work-breakdown-structure. (6) Develop a coupled numerical model to evaluate potential effects on the rock mass and optimal heater configuration, power, and monitoring borehole orientations.The models and insight from these experiments will have broad applicability to engineered systems, e.g., enhanced geothermal systems, CO2 sequestration and subsurface contaminant transport. Educational outreach will involve facility tours and a traveling benchscale ?mock-up? demonstration experiment.