Hydraulic 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.
