Collaborative Research: Characterization of Fractured Rock Aquifers Using Hydromechanical Well Tests

世界上碳氢化合物和淡水供应的一个重要部分出现在具有穿过紧密基质的裂缝的地质构造中。 可以理解的是，已经投入了相当大的努力来理解这些流体是如何沿着沿着裂缝储存和传输通过孔隙空间的。 虽然通常被视为刚性管道，但岩石中的裂缝实际上有些顺从，即使是适度的压力增加也会张开，当压力下降时会收缩闭合。 在抽水的同时测量和解释位移和压力是水力机械试井的本质。 压力和位移的测量可用于确定蓄水层的储水性，仅使用抽水井的数据;传统方法需要使用观测井来估计储水性。 该项目的目的是开发和完善进行和分析水力机械试井的现场技术。 该项目的动机是努力解决含水层特征，良好的性能，联合形成，和地球潮汐。 拟议项目的智力价值包括三个主要领域的进展：a）断裂流体力学的理论分析，B）现场技术和仪器，c）现场应用和假设检验的网站下面的断裂岩石含水层。 该项目将在便携式引伸计方面产生创新，可用于试井，并将开发新的理论分析，用于预测和反演水力机械试井期间获得的位移和压力信号。 可以反演裂缝中耦合流体流动和变形的轴对称模型，以估计距抽油井一定距离处的非均质性。 水力机械试井作为一种独立的技术和与其他方法相结合的技术，在裂隙岩石含水层的表征方面提供了希望。 该项目将提供与地下水生产和补救、地热能、石油和天然气生产、深井注入处置危险废物、处置库中的核废物、地震和海啸预测、滑坡力学、岩石力学以及与断裂岩石中的流体流动和变形有关的各种其他学科有关的见解。 该项目将启动克莱姆森和格鲁吉亚理工学院之间的创新教育伙伴关系，为地质力学和水文地质学各级学生的培训提供独特的机会。 此外，我们还将启动一项计划，使中学地球科学教师每年夏天都能了解试井知识，并将试井练习带给学生。

An important fraction of world supplies of hydrocarbons and fresh groundwater occurs in geologic formations with fractures cutting through a tight matrix. It is understandable that considerable effort has been put into efforts to understand how these fluids are stored and transmitted through the pore spaces along fractures. Although commonly viewed as rigid conduits, fractures in rock are actually somewhat compliant, gapping open in response to even modest increases in pressure and shrinking closed when pressure drops. Measuring and interpreting both displacement and pressure while pumping is the essence of a hydromechanical well test. Measurements of both pressure and displacement can be used to determine the storativity of an aquifer using data from a pumping well alone; conventional methods require using an observation well to estimate storativity. The purpose of this project is to develop and refine field techniques for conducting and analyzing hydromechanical well tests. The project is motivated by efforts to address aquifer characterization, well performance, joint formation, and Earth tides. The intellectual merit of the proposed project includes advances in three primary arenas: a) theoretical analyses of fracture hydromechanics, b) field techniques and instrumentation, c) field applications and hypothesis testing at sites underlain by fractured rock aquifers. The project will produce innovations in portable extensometers that can be used during well tests, and new theoretical analyses will be developed for predicting and inverting displacement and pressure signals obtained during hydromechanical well tests. It is possible to invert an axisymmetric model of coupled fluid flow and deformation in fractures to estimate heterogeneities at some distance from the pumping well. Hydromechanical well tests offer promise, both as a technique that stands alone and as one that is integrated with other methods in the characterization of fracture rock aquifers. This project will provide insights that cut across fields related to groundwater production and remediation, geothermal energy, oil and gas production, disposal of hazardous wastes by deep well injection, disposal of nuclear wastes in repositories, earthquake and tsunami prediction, landslide mechanics, rock mechanics, and a variety of other disciplines concerned with fluid flow and deformation in fractured rock. The project will initiate an innovative educational partnership between Clemson and Georgia Tech that will provide unique opportunities for training students at all levels in geomechanics and hydrogeology. Furthermore, we will initiate a program to enable middle school earth science teachers each summer to learn about well testing and bring well testing exercises to their students.