Quantitative Characterization of the Vibratory Enhancement of Organic-Fluid Flow in Porous Media: Integrated Experimental and Theoretical Approach

由于毛细管阻力导致有机流体在孔隙中被截留，石油开采和地下水修复的效率受到限制。已经观察到弹性波可以增加流体的萃取，尽管对这一现象还没有给出令人满意的解释。物理认识的缺乏阻碍了储层和含水层增产技术的发展。非水相液体（NAPLs）的振动释放的物理性质在最近由pi完成的NSF项目中得到了阐明。这种机制描述了振动如何“推动”被困的神经节越过毛细血管屏障，直到它们被释放。该机制的推论已在专门设计的实验室实验中得到验证。该释放机制的提出为开发具有实际几何形状的多孔网络中振动去除NAPL的预测模型铺平了道路。开发这样一个定量模型，建立在当前对潜在孔隙尺度过程的理解之上，是该项目的目标。这一目标将通过满足三个特定的目标，代表一个综合的实验，理论和数值方法来实现。目的1。开发分析工具，用于在孔隙水平上通过振动精确分析神经节释放的动力学，描述这种现象对各种参数的依赖。这项工作将在允许物理透明解决的方程中表达施加在神经节上的力的平衡。目标2。通过使用计算流体动力学，将该过程的数值模型“升级”到二维多孔域，这是对简单的一维毛细管的关键改进。鉴于增加的孔连通性和多半月板几何形状，将阐明一维管和高维管之间动员的物理相似性和差异性。目标3。进行全面的平面微模型实验室实验，以记录振动刺激过程，重点关注个体被困神经节的行为和大流量增强。观察和验证分散有机相中潜在的孔隙尺度过程和相互作用，包括可能的破裂和合并。将特别注意验证理论模型与观测之间的一致性。预测振动刺激结果的可能性，以及他们在个体和大流量水平上的物理理解，将被测试。智力价值：该项目在基础物理水平上满足了对社会具有高度意义的具有挑战性的实际需求。pi最近完成了一项由美国国家科学基金会资助的工作，其中关于NAPL流动振动增强的潜在机制的新想法已经开发和发表。项目负责人已经展示了他们团队所代表的跨学科、协作方法的明显好处。新目标是作为先前工作的结果而发展起来的，新阶段将以pi所创建的知识为基础开始。更广泛的影响：毛细作用的基础科学和基于毛细作用的技术都将从研究结果中受益。其结果将对一系列处理弹性波、多相流和多孔介质的科学学科产生直接的兴趣。PIs之前的NSF项目培养了两位年轻的博士学者，一位是地球物理学的，另一位是化学工程的。这种教育影响将持续下去。Beresnev和Vigil都在各自的学科中教授应用地球物理和化学工程的本科课程，这些课程的成果已经完全整合在一起。建立的实验基础设施已经使化学工程系的本科教育受益。

The efficiency of petroleum recovery and groundwater remediation is limited by the resistive capillary forces that cause the entrapment of organic fluids in pores. Elastic waves have been observed to increase the fluid extraction, although no satisfactory explanation of this phenomenon has been given. The lack of physical understanding has hindered the development of field technologies of reservoir and aquifer stimulation. The physics of the vibratory liberation of NAPLs (non-aqueous-phase liquids) has been elucidated in an NSF project completed recently by the PIs. This mechanism describes how vibrations "nudge" the entrapped ganglia over the capillary barrier until they are released. The corollaries of the mechanism have been validated in a specially designed laboratory experiment. The formulation of the liberation mechanism paves the way for the development of a predictive model of NAPL removal by vibrations in porous networks with realistic geometries. Developing such a quantitative model, building on the current understanding of the underlying pore-scale process, is the goal of the project. This goal will be achieved through meeting three specific objectives, representing an integrated experimental, theoretical, and numerical approach. Objective 1. Developing analytical tools for the accurate analysis of the dynamics of ganglion liberation, at a pore level, by vibrations, describing the phenomenon's dependence on various parameters. This work will express the balance of forces exerted upon a ganglion in equations allowing physically transparent solutions. Objective 2. "Upscaling" the process's numerical model to 2D porous domains as a key improvement over simple 1D capillary tubes, with the use of computational fluid dynamics. The similarities and differences in the physics of the mobilization between 1D tubes and higher dimensions, in view of the added pore-connectivity and multiple-menisci geometries, will be illuminated. Objective 3. Conducting comprehensive flat-micromodel laboratory experiments to document the vibratory-stimulation process, focused on both the behavior of individual entrapped ganglia and bulk-flow enhancement. Observing and verifying the underlying pore-scale process and interactions in the dispersed organic phase, including possible break-up and coalescence. Special attention will be given to verifying the agreement between the theoretical models and observations. The possibility of predicting the vibratory-stimulation results with their physical understanding achieved, at both individual-blob and bulk-flow levels, will be tested. Intellectual Merit: The project speaks to a challenging practical need of high significance to society, at the basic-physics level. The PIs have recently completed an NSF-funded effort, in which novel ideas on the underlying mechanism of the vibratory enhancement of NAPL flow have been developed and published. The PIs have demonstrated a clear benefit of the cross-disciplinary, collaborative approach that their team represents. The new goal has evolved as a result of the previous effort, and the new phase will start on the base of knowledge that the PIs have created. Broader Impacts: Both fundamental science of capillarity and the technologies based on it will benefit from the results. The outcomes will be of immediate interest to a range of scientific disciplines dealing with elastic waves, multi-phase flow, and porous media. The PIs' previous NSF project has educated two young Ph. D. scholars, one in geophysics and one in chemical engineering. This education impact will continue. Both PIs Beresnev and Vigil teach undergraduate courses in their respective disciplines of applied geophysics and chemical engineering, in which the results have been fully integrated. The experimental infrastructure created has already benefited undergraduate education in the Chemical Engineering Department.