FRACTURED AQUIFER CHARACTERIZATION USING SMART NON-NEWTONIAN TRACERS

使用智能非牛顿示踪剂表征破裂含水层

• 批准号: 1446915
• 负责人: John Selker
• 金额: $ 28.5万
• 依托单位: Oregon State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-04-15 至 2018-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1446915&HistoricalAwards=false
• 关键词: FRACTURED; AQUIFER; CHARACTERIZATION; USING; SMART

Title: Fractured Aquifer Characterization Using Smart Non-Newtonian TracersInvestigator: John S. Selker, Oregon State UniversityProposal Number: EAR 1446915Fractured rock aquifers are the only source of water in many parts of the United States and much of the rest of the world. Understanding these waters, and the materials that water transports, is critically needed for providing and protecting safe water drinking water. In addition, the role of water flow fractured rocks is important in the formation of mineral deposits and in the development of deep geothermal systems. This research will also benefit the extraction of oil and gas from fractured reservoirs, including those created by fracking. Thus, this study is both theoretical and potentially very practical in nature. Methods that can identify fluid flow paths in fractures have been very limited. This research will conduct lab experiments that will use unique fluids that can sample the major flow paths more effectively. These are the Non-Newtonian fluids (e.g., guar gum and other food grade fluids). The novel methods proposed seek a practical means of gaining insight into flow in fractured rock aquifers and other fractured rock systems. In parallel to the laboratory work, a field experiment will be performed at the observatory site of Ploemeur, France, where a unique fracture-flow field site has been established for just this kind of experiment. In addition, two undergraduate students will participate in the research.The identification of dominant flow paths, their connectivity, and their hydraulic properties in fractured rocks is critical for fluid flow and solute transport. Tracer testing can characterize such aquifer properties from laboratory to field scales. Classical tracer test interpretations allow defining a mean "effective hydraulic" aperture based on simplified transport models. This research will: 1) develop an innovative tracer approach using non-Newtonian ("shear-thinning") fluids to identify aperture distributions of preferential flow paths in natural fractured networks and 2) investigate flow behavior of these "smart" tracers, knowing their rheology, in order to characterize the hydraulic properties of fracture systems. By adjusting the viscosity, the research will be able to select for specific thresholds or aperture size that allow flow, while smaller apertures will be essentially "frozen" in a gel-filled condition. This will be tested in the laboratory and at the instrumented field site to demonstrate the utility in characterizing aquifer properties. The experimental observations of the movement of shear-thinning fluid in realistic rock apertures will be compared to theoretical models of fluid transport. Additionally, numerical modeling will explore the hypothesis identified by the experimental approach (e.g., stable (non-Newtonian chasing water) vs unstable (water chasing non-Newtonian) fluid displacement). Based on preliminary results, the field experimental approach will to test the validity of the proposed approach. Coupled time-lapse GPR measurement will be used during tracer tests in order to document the preferential paths taken by the tracer. The methodology will be tested in a unique, well-characterized fractured granitic formation in France where complete fracture geometry and hydraulic characteristic have already been defined based on multiple hydro-geophysical approaches. Finally, numerical models will investigate the sensitivity of first order parameters that control flow transport of non-Newtonian fluids in such context. Theoretical concepts related to fractured aquifer hydrogeology will be presented and addressed experimentally in the lab.

标题：使用智能非纽顿式Tracersinvestigator的含水层碎屑表征：俄勒冈州立大学普罗门郡的John S. Selker编号：EAR 1446915划分的岩石含水层是美国许多地区唯一的水源。了解这些水以及水的运输材料，为提供和保护安全的水饮用水至关重要。此外，水流骨折的作用在形成矿物沉积物和深地热系统的发展中很重要。这项研究还将受益于从破裂的储层中提取石油和天然气，包括压裂产生的水库。 因此，这项研究本质上既是理论上的，又可能非常实用。可以鉴定裂缝中流体流动路径的方法非常有限。 这项研究将进行实验实验，这些实验将使用独特的流体，可以更有效地采样主要的流动路径。 这些是非牛顿液（例如瓜尔胶和其他食物级液体）。 这项新方法提出的方法寻求一种实用方法，以了解破裂的岩石含水层和其他断裂的岩石系统中的流动。与实验室工作并行，将在法国普洛梅尔的天文台进行现场实验，在该天文台上，仅建立了这种独特的裂缝 - 流场现场用于此类实验。此外，两名本科生将参与研究。鉴定主要流动路径，它们的连通性以及它们在断裂的岩石中的液压特性对于流体流量和溶质传输至关重要。示踪剂测试可以表征从实验室到现场尺度的此类含水层的特性。经典的示踪剂测试解释允许根据简化的传输模型定义平均“有效的液压”光圈。这项研究将：1）使用非牛顿（“剪切粉状”）流体开发一种创新的示踪剂方法，以识别自然断裂网络中优先流动路径的孔径分布和2）研究这些“智能”示踪剂的流动行为，知道他们流变学，以表征断裂系统的液压特性。通过调整粘度，研究将能够选择允许流动的特定阈值或光圈大小，而较小的孔径本质上将在充满凝胶填充条件下“冷冻”。这将在实验室和仪器现场进行测试，以证明表征含水层性能的实用性。将剪切液在逼真的岩石孔中移动的实验观察结果将与流体转运的理论模型进行比较。此外，数值建模将探讨通过实验方法（例如，稳定（非牛顿追逐水）与不稳定（水追逐非牛顿）流体位移所确定的假设。基于初步结果，现场实验方法将测试所提出方法的有效性。在示踪剂测试期间将使用耦合的延时GPR测量，以记录示踪剂所采用的优先路径。该方法将在法国的独特，特征良好的断裂花岗岩形成中进行测试，在该花岗岩形成中，已经根据多种水力地球物理学方法定义了完全断裂的几何形状和液压特征。最后，数值模型将研究一阶参数的灵敏度，这些参数在这种情况下控制非牛顿流体的流动运输。将在实验室中提出和实验介绍与含水层水文地质学有关的理论概念。