Elucidating Physicochemical Processes Affecting Transport Phenomena Resulting from Hydraulic Fracturing of Natural Gas Reservoirs

1604314 Miller，卡斯T.水力压裂的使用已经允许从以前无法到达的来源提取天然气;然而，由于来自注入地点的流体迁移的污染的可能性，水力压裂也引起了关注。拟议项目的目的是提高与水力压裂液通过多孔介质和裂缝介质的运输相关的物理化学过程的理解。这种方法将允许对环境的潜在不利影响进行更详细的评估。PI将调查流体成分和物理性质之间的关系，水力压裂化学品对固体介质的吸附（即，支撑剂和页岩），以及多孔和裂缝介质中多组分非牛顿流体的流动和传输。常见压裂化学品的水溶液将根据密度和流变特性进行表征。将进行批量测试，以测量压裂化学品对相关固体材料的吸附。微观模型将用于阐明孔隙/裂缝尺度上的流体流动特性。冲洗实验将在一维和二维，均相和非均相系统中进行。实验将研究具有一系列流体成分的非牛顿压裂液的压力-流速关系，以及流体中各个物质的传输。严格的理论模型，将开发与实验工作结合使用的平均理论框架的限制。该项目的实验部分将提供相关温度和压力下的综合数据集，涉及：（1）流体组成对物理性质的影响，（2）水力压裂化学品在相关固体介质上的吸附，（3）多组分非牛顿流体在实际多孔和裂缝介质系统中的流动行为，以及，（4）溶解态在非牛顿流体中的分散。实验工作将结合使用磁约束平均理论方法的建模进行。这种方法将导致一个宏观模型的发展，是符合热力学原理，并允许明确识别的子尺度过程和感兴趣的变量之间的关系。这样一个模型的发展将大大改善现有的状态建模这样的系统，指导进一步的实验和计算工作，并提供一个一致的框架，以更好地探测多孔介质中复杂的流体行为的基本方面。该项目将通过建立一个网站、举办公共论坛和参加联合国大学环境研究所的环境IDEA方案来传播研究结果。此外，PI将：（1）通过课程内容、学生研究和科学推广对教育做出贡献;（2）代表性不足的研究人员的参与和与少数民族招聘计划的联系;（3）在环境工程、环境化学和污染物水文学期刊上广泛传播研究结果;（4）独特数据集和实验视频图像的数字存档和传播;以及，（5）扩大了与国际合作者的联系，这些合作者致力于多相系统的互补方面。此外，本研究所选择的物理过程和化学成分是常见的环境修复应用程序，并将提高对所有此类系统的理解。

1604314Miller, Cass T.The use of hydraulic fracturing has allowed for the extraction of natural gas from previously inaccessible sources; however, hydraulic fracturing has also raised concerns due to the potential for contamination from migration of fluids from injection sites. The objective of the proposed project is to improve understanding of the physicochemical processes associated with the transport of hydraulic fracturing fluids through porous media and fractured media. This approach will allow a more detailed assessment of the potential adverse effects to the environment.The PI will investigate the relationship between fluid composition and physical properties, sorption of hydraulic fracturing chemicals to solid media (i.e., proppants and shale), and the flow and transport of multicomponent, non-Newtonian fluids in porous and fractured media. Aqueous solutions of common fracturing chemicals will be characterized with respect to density and rheological properties. Batch tests will be conducted to measure the sorption of fracturing chemicals to relevant solid materials. Micro-models will be used to elucidate fluid flow characteristics on the pore/fracture scale. Flushing experiments will be conducted in one- and two-dimensional, homogeneous and heterogeneous systems. Experiments will investigate the pressure-flow rate relationship for non-Newtonian fracturing fluids with a range of fluid compositions, and the transport of individual species within the fluid. Rigorous theoretical models will be developed in conjunction with the experimental work using the thermodynamically constrained averaging theory framework. The experimental portion of the project will provide a comprehensive dataset at relevant temperatures and pressures regarding: (1) the effect of fluid composition on physical properties, (2) the sorption of hydraulic fracturing chemicals on relevant solid media, (3) the flow behavior of multicomponent, non-Newtonian fluids in realistic porous and fractured media systems, and, (4) dispersion of dissolved species in non-Newtonian fluids. The experimental work will be conducted in conjunction with modeling using the thermodynamically constrained averaging theory approach. This method will result in the development of a macroscale model that is consistent with thermodynamic principles, and which allows for explicit identification of subscale processes and relationships between variables of interest. The development of such a model will greatly improve upon the existing state of modeling such systems, direct further experimental and computational work, and provide a consistent framework with which to better probe the fundamental aspects of complex fluid behavior in porous media. The project will disseminate the finding of the research by developing a web site, holding public forums, and participation in the UNCs Institute for the Environment IDEA program. In addition, the PI will: (1) contributions to education through course content, student research, and science outreach; (2) participation of underrepresented researchers and linkages to minority recruitment programs; (3) broad dissemination of findings in environmental engineering, environmental chemistry, and contaminant hydrology journals; (4) digital archiving and dissemination of unique data sets and video images of experiments; and, (5) expanded ties with international collaborators that work on complementary aspects of multiphase systems. In addition, the physical processes and chemical components chosen for this study are common to environmental remediation applications and will improve understanding of all such systems.