UNS: Fluid-driven Fracture of Elastic Materials, Flowback Dynamics and the Effect of Proppants

UNS：弹性材料的流体驱动断裂、返排动力学和支撑剂的影响

• 批准号: 1509347
• 负责人: Howard Stone
• 金额: $ 30万
• 依托单位: Princeton 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: 2015-07-01 至 2018-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1509347&HistoricalAwards=false
• 关键词: UNS; Fluid; driven; Fracture; Elastic

1509347 (Stone)The goal of the proposed research is to explore fluid dynamics phenomena that are related to hydraulic fracturing - an area of national importance for domestic energy production. The work proposed is based on fundamental theoretical analysis and elegant experiments conducted in simplified and very well-controlled systems of gelatin to model an elastic geological formation. When the pressure is relieved after hydraulic cracking of an elastic material, the fluid can flow back. This is a process that occurs in hydraulic fracturing and has implications for the production of hydrocarbons as well as for the environment, since hydraulic fracking fluids need to be monitored in the subsurface. In contrast to fluid-driven cracking of elastic materials, for which there is a substantial theoretical literature but only limited experiments, there is a much smaller literature on flowback when the pressure controlling injection is released. This proposal is about laboratory experiments and mathematical modeling to (i) understand and characterize the coupled fluid flow and elastic stresses of fluid-driven cracking followed by flowback as the elastic stresses relax, and (ii) will do so including a particle-laden fluid (the proppant). The experiments will make use of gelatin materials that are elastic but brittle and have been described previously in the solid-earth geophysics literature for the study of fluid-driven cracks. Hence, there will be a link between fluid injection and flowback to the elastic response of the bulk material, with results interpreted using appropriately scaled quantities and dimensional analysis. These experimental and modeling efforts will be among the first to describe the dynamics of flowback and the role of the proppant. Graduate students will be involved in research and a series of outreach lectures, the Harvard and Princeton holiday lectures on engineering and science for children and families, will be offered based on the research findings of the project.

1509347（Stone）拟议研究的目标是探索与水力压裂相关的流体动力学现象 - 这是国内能源生产的重要领域。所提出的工作基于基础理论分析和在简化且控制良好的明胶系统中进行的优雅实验，以模拟弹性地质构造。当弹性材料水力裂解后压力释放时，流体可以回流。这是水力压裂中发生的过程，对碳氢化合物的生产以及环境都有影响，因为需要在地下监测水力压裂液。与弹性材料的流体驱动破裂相比，有大量的理论文献但只有有限的实验，而有关压力控制注入释放时回流的文献要少得多。该提案涉及实验室实验和数学建模，以（i）理解和表征流体驱动开裂的耦合流体流动和弹性应力，然后随着弹性应力松弛而回流，并且（ii）将包含充满颗粒的流体来实现这一点（支撑剂）。这些实验将利用具有弹性但脆性的明胶材料，并且先前在固体地球物理学文献中已描述过用于研究流体驱动的裂缝。因此，流体注入和回流与散装材料的弹性响应之间存在联系，并使用适当缩放的数量和尺寸分析来解释结果。这些实验和建模工作将首先描述返排动力学和支撑剂的作用。研究生将参与研究，并根据该项目的研究结果举办一系列外展讲座，哈佛和普林斯顿针对儿童和家庭的工程和科学假期讲座。