CAREER: Hydraulic Fractures at Shallow Depths

9876124-水力压裂提供了一个机会，可以减少修复细粒矿床的巨大费用。这项建议的目的是利用诱发裂缝对水文系统的力学和影响作为水文地质学教学和研究的基础。该计划将包括一系列课程和水力压裂应用的研究工作。一个重要的主题将是提高学生的基本数学技能和使用这些技能解决与力学和水文地质有关的问题的能力。课程顺序将从介绍分析地质过程的数学方法开始，旨在激励学生学习数学方法，以此来提高他们对地质学的理解。第二门课程将基于下面概述的研究结果和相关材料，涵盖沉积物或岩石中天然和诱导裂缝的力学和水文学。研究将有两个主要目标；一个是了解控制水力裂缝形成的过程，另一个是了解在低渗透材料中产生充砂水力裂缝是如何影响流体流动的。这两个问题都将通过受控现场实验和使用理论模型进行研究。测量浅层土壤中的应力状态和断裂韧性(对了解裂缝扩展至关重要的参数)的方法是有限的，因此这项研究的早期阶段将确定并在必要时开发现场表征方法。现场观测将采用水力裂缝发育的三维模拟器(HYFRANC-3D)进行分析。最终目标是发展基于现场条件预测裂缝形态的能力。从详细的现场和模型研究中得出的结论将通过将预测与之前调查期间形成水力裂缝的十几个地点的观测进行比较来检验。该项目将促进我们对诱发裂缝的形成和地下影响的理解，同时培训学生将现场调查与数学分析相结合，以研究裂隙水文系统。

9876124MurdochHydraulic fractures provide an opportunity to reduce the great expense of remediating fine-grained deposits. The purpose of this proposal is to use the mechanics and effects of induced fractures on hydrological systems as a basis for teaching and research in hydrogeology. The program will consist of a series of courses and a research effort into the application of hydraulic fractures. An important theme will be to improve the basic math skills and the ability of students to use those skills to solve problems related to mechanics and hydrogeology. The course sequence will begin with an introduction to the mathematical methods for analyzing geological processes in an approach intended to motivate students to learn mathematical methods as a means to improve their understanding of geology. A second course will cover the mechanics of fracturing and the hydrology of natural and induced fractures in sediment or rock based on finding from the research outlined below, and related material.The research will have two primary goals; one is to understand processes that control the form of a hydraulic fracture, the other is to understand how the flow of fluid is affected by creating sand-filled hydraulic fractures in low permeability materials. Both issues will be investigated by controlled field experiments and using theoretical models. Methods for measuring state-of-stress and fracture toughness (parameters critical to understanding fracture propagation) in shallow soils are limited, so the early stages of this research will identify and, if necessary, develop field methods for site characterization. Field observations will be analyzed by adapting a 3-D simulator of hydraulic fracture growth (HYFRANC-3D). The ultimate objective is to develop the capability to predict fracture form based on in-situ conditions. Conclusions derived from the detailed field and modeling studies will be tested by comparing predictions to observations from more than a dozen sites where hydraulic fractures were created during previous investigations. The program will advance our understanding of the formation and subsurface effects of induced fractures while training students to combine field investigations with mathematical analysis to investigate fractured hydrological systems.