Download or read book Geometric Controls on Partially Saturated Flow Through Natural Rock Fractures written by Mampho Maoyi and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Partially saturated rock fracture flow informs on groundwater recharge processes, water affecting infrastructure, and water quality deterioration. This study examines partially saturated flow through natural fractures in double porosity media. Rock samples are characterised in terms of bulk mineralogical composition, as well as its geomechanical properties including, for instance, fracture aperture and roughness, representing the overall rock mass geometry. Samples are tested at different angles of inclination, being 0AÌ2℗ʻ, 23AÌ2℗ʻ, 60AÌ2℗ʻ, and 90AÌ2℗ʻ orientation. Samples are wetted while observing inflow and outflows from the dry to wetting and to the rewetting phase conditions; calculating water budgets, linear flow velocities, and Reynolds numbers. The change in the hydraulic head and the flow of water in the different cross-sectional areas follows the Bernoulli and continuity principle. The observed flow mechanism for shale is finger flow, and the flow regime is transitional turbulent flow at low flow meter discharge rates, and turbulent rotational flow for high flow meter rates. Conversely, the flow mechanism for quartzite is film flow, while the flow regime at high and low flow meter rates are turbulent and laminar rotational flow, respectively. These flow mechanisms show fluid instabilities and rapid infiltration of water under unsaturated continuous influx conditions. Preferential flow prevails in the fracture as water exits the fracture parallel or perpendicular to the flow direction. Subsequently, water may rewet the pre-existing flow paths from the initially dry phase, form new paths, merge flow paths, or the wetting front-width increases. Inclination affects the formation of the overall flow pattern in the fractures, but not the flow rate. The aperture of the shale is smaller than that of quartzite, and the width of the aperture influences the observed flow mechanisms, as tight discontinuities are more likely to have forces counteracting free water movement, affecting the permeability. Capillary forces are significant in narrower apertures, whereas gravitational forces are prominent in quartzite. Joint roughness coefficients show that the fracture surfaces are not identical; roughness induces turbulence and accounts for flow channelling.
Download or read book Rock Fractures and Fluid Flow written by National Research Council and published by National Academies Press. This book was released on 1996-08-27 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt: Scientific understanding of fluid flow in rock fracturesâ€"a process underlying contemporary earth science problems from the search for petroleum to the controversy over nuclear waste storageâ€"has grown significantly in the past 20 years. This volume presents a comprehensive report on the state of the field, with an interdisciplinary viewpoint, case studies of fracture sites, illustrations, conclusions, and research recommendations. The book addresses these questions: How can fractures that are significant hydraulic conductors be identified, located, and characterized? How do flow and transport occur in fracture systems? How can changes in fracture systems be predicted and controlled? Among other topics, the committee provides a geomechanical understanding of fracture formation, reviews methods for detecting subsurface fractures, and looks at the use of hydraulic and tracer tests to investigate fluid flow. The volume examines the state of conceptual and mathematical modeling, and it provides a useful framework for understanding the complexity of fracture changes that occur during fluid pumping and other engineering practices. With a practical and multidisciplinary outlook, this volume will be welcomed by geologists, petroleum geologists, geoengineers, geophysicists, hydrologists, researchers, educators and students in these fields, and public officials involved in geological projects.
Download or read book Fluid Flow in Fractured Rocks written by Robert W. Zimmerman and published by John Wiley & Sons. This book was released on 2023-12-19 with total page 293 pages. Available in PDF, EPUB and Kindle. Book excerpt: FLUID FLOW IN FRACTURED ROCKS "The definitive treatise on the subject for many years to come" (Prof. Ruben Juanes, MIT) Authoritative textbook that provides a comprehensive and up-to-date introduction to fluid flow in fractured rocks Fluid Flow in Fractured Rocks provides an authoritative introduction to the topic of fluid flow through single rock fractures and fractured rock masses. This book is intended for readers with interests in hydrogeology, hydrology, water resources, structural geology, reservoir engineering, underground waste disposal, or other fields that involve the flow of fluids through fractured rock masses. Classical and established models and data are presented and carefully explained, and recent computational methodologies and results are also covered. Each chapter includes numerous graphs, schematic diagrams and field photographs, an extensive reference list, and a set of problems, thus providing a comprehensive learning experience that is both mathematically rigorous and accessible. Written by two internationally recognized leaders in the field, Fluid Flow in Fractured Rocks includes information on: Nucleation and growth of fractures in rock, with a multiscale characterization of their geometric traits Effect of normal and shear stresses on the transmissivity of a rock fracture and mathematics of fluid flow through a single rock fracture Solute transport in rocks, with quantitative descriptions of advection, molecular diffusion, and dispersion Fluid Flow in Fractured Rocks is an essential resource for researchers and postgraduate students who are interested in the field of fluid flow through fractured rocks. The text is also highly suitable for professionals working in civil, environmental, and petroleum engineering.
Download or read book Variably Saturated Flow Through Discrete Open Fractures written by Brendon Ronald Jones and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Implications of improved understanding of partially saturated flow in jointed rock masses are numerous, especially given the complexity, heterogeneity and anisotropy of the intermediate fractured vadose zone. One such implication is the quantification of water movement for engineering purposes. This thesis aims to contribute to the understanding of variably saturated flow through discrete open fractures as it applies to rock engineering and geotechnical engineering applications. The initial phase comprises the analyses of results from Lugeon tests conducted at De Hoop Dam that guide a subsequent experimental phase by identifying field parameters and relationships that influence variably saturated flow processes. The series of flow visualisation experiments are developed using transparent smooth parallel fracture replicas with differing flow rates and inclinations, modelled in a geotechnical centrifuge. The findings show that the geotechnical centrifuge is a viable experimental tool for the replication of variably saturated fracture flow mechanisms. Additionally, it was found that preferential flow occupies the minority of the cross-sectional area despite the flux, and that flow becomes a matter of the continuity principle requiring substantially higher flow rates given the very low degree of saturation. Furthermore, these preferential paths are characterised by non-Darcian flow, which can be successfully evaluated using the Forchheimer relationship. The relevance of how flow occurs through fractures at partial saturation in the engineering context is understated, especially given the quest to achieve better quantification of in-situ tests during site investigations. The results prove that using common Darcian-based empirical correlations to define hydraulic conductivities from insitu tests is cautioned. Furthermore, these volume-effective approaches do not contribute to fundamental research and require a deeper understanding of the small-scale processes in the intermediate fractured vadose zone. The design of infrastructure therefore cannot be optimised without a thorough understanding of the complex flow conditions in natural and engineered rock masses.
Download or read book Statistical Analysis of Liquid Seepage in Partially Saturated Heterogenous Fracture Systems written by Tai-Sheng Liou and published by . This book was released on 1999 with total page 512 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Geologic Fracture Mechanics written by Richard A. Schultz and published by Cambridge University Press. This book was released on 2019-08-08 with total page 611 pages. Available in PDF, EPUB and Kindle. Book excerpt: Introduction to geologic fracture mechanics covering geologic structural discontinuities from theoretical and field-based perspectives.
Download or read book Flow and Transport Through Unsaturated Fractured Rock written by Daniel D. Evans and published by . This book was released on 1987 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Hydrology and Geochemistry of Yucca Mountain and Vicinity Southern Nevada and California written by John S. Stuckless and published by Geological Society of America. This book was released on 2012 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Environmental Rock Engineering written by S. Murata and published by CRC Press. This book was released on 2003-01-01 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is a collection of papers presented at the 1st Kyoto International Symposium on Underground Environment entitled "Role of Geo-technology to the Underground Environment". Consists of nine keynote papers, thirty-one technical papers and fifteen papers resulting from the poster presentations, each covering a vital aspect of underground engineering.
Download or read book Modeling Fluid Migration Through Physically based Fracture Networks written by Carl Edward Renshaw and published by . This book was released on 1993 with total page 378 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fractured Porous Media written by Pierre M. Adler and published by Oxford University Press, USA. This book was released on 2013 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a systematic treatment of the geometrical and transport properties of fractures, fracture networks, and fractured porous media. It is divided into two major parts. The first part deals with geometry of individual fractures and of fracture networks. The use of the dimensionless density rationalizes the results for the percolation threshold of the networks. It presents the crucial advantage of grouping the numerical data for various fracture shapes. The second part deals mainly with permeability under steady conditions of fractures, fracture networks, and fractured porous media. Again the results for various types of networks can be rationalized by means of the dimensionless density. A chapter is dedicated to two phase flow in fractured porous media.
Download or read book Characterization Modeling Monitoring and Remediation of Fractured Rock written by National Academies of Sciences, Engineering, and Medicine and published by National Academies Press. This book was released on 2021-01-29 with total page 177 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fractured rock is the host or foundation for innumerable engineered structures related to energy, water, waste, and transportation. Characterizing, modeling, and monitoring fractured rock sites is critical to the functioning of those infrastructure, as well as to optimizing resource recovery and contaminant management. Characterization, Modeling, Monitoring, and Remediation of Fractured Rock examines the state of practice and state of art in the characterization of fractured rock and the chemical and biological processes related to subsurface contaminant fate and transport. This report examines new developments, knowledge, and approaches to engineering at fractured rock sites since the publication of the 1996 National Research Council report Rock Fractures and Fluid Flow: Contemporary Understanding and Fluid Flow. Fundamental understanding of the physical nature of fractured rock has changed little since 1996, but many new characterization tools have been developed, and there is now greater appreciation for the importance of chemical and biological processes that can occur in the fractured rock environment. The findings of Characterization, Modeling, Monitoring, and Remediation of Fractured Rock can be applied to all types of engineered infrastructure, but especially to engineered repositories for buried or stored waste and to fractured rock sites that have been contaminated as a result of past disposal or other practices. The recommendations of this report are intended to help the practitioner, researcher, and decision maker take a more interdisciplinary approach to engineering in the fractured rock environment. This report describes how existing tools-some only recently developed-can be used to increase the accuracy and reliability of engineering design and management given the interacting forces of nature. With an interdisciplinary approach, it is possible to conceptualize and model the fractured rock environment with acceptable levels of uncertainty and reliability, and to design systems that maximize remediation and long-term performance. Better scientific understanding could inform regulations, policies, and implementation guidelines related to infrastructure development and operations. The recommendations for research and applications to enhance practice of this book make it a valuable resource for students and practitioners in this field.
Download or read book Reactive Transport in Natural and Engineered Systems written by Jennifer Druhan and published by Walter de Gruyter GmbH & Co KG. This book was released on 2020-03-04 with total page 514 pages. Available in PDF, EPUB and Kindle. Book excerpt: Open system behavior is predicated on a fundamental relationship between the timescale over which mass is transported and the timescale over which it is chemically transformed. This relationship describes the basis for the multidisciplinary field of reactive transport (RT). In the 20 years since publication of Review in Mineralogy and Geochemistry volume 34: Reactive Transport in Porous Media, RT principles have expanded beyond early applications largely based in contaminant hydrology to become broadly utilized throughout the Earth Sciences. RT is now employed to address a wide variety of natural and engineered systems across diverse spatial and temporal scales, in tandem with advances in computational capability, quantitative imaging and reactive interface characterization techniques. The present volume reviews the diversity of reactive transport applications developed over the past 20 years, ranging from the understanding of basic processes at the nano- to micrometer scale to the prediction of Earth global cycling processes at the watershed scale. Key areas of RT development are highlighted to continue advancing our capabilities to predict mass and energy transfer in natural and engineered systems.
Download or read book Energy Research Abstracts written by and published by . This book was released on 1993-02 with total page 366 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Two phase Flow Visualization and Relative Permeability Measurement in Transparent Replicas of Rough walled Rock Fractures written by and published by . This book was released on 1991 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Understanding and quantifying multi-phase flow in fractures is important for mathematical and numerical simulation of geothermal reservoirs, nuclear waste repositories, and petroleum reservoirs. While the cubic law for single-phase flow has been well established for parallel-plate fractures theoretically and experimentally, no reliable measurements of multi-phase flow in fractures have been reported. This work reports the design and fabrication of an apparatus for visualization of two-phase flow and for measurement of gas-liquid relative permeability in realistic rough-walled rock fractures. A transparent replica of a natural rock fracture from a core specimen is fabricated by molding and casting in clear epoxy. Simultaneous flow of gas and liquid with control of capillary pressure at inlet and outlet is achieved with the Hassler ''sandwich'' design: liquid is injected to the fracture through a porous block, while gas is injected directly to the edge of the fracture through channels in the porous block. A similar arrangement maintains capillary separation of the two phases at the outlet. Pressure drops in each phase across the fracture, and capillary pressures at the inlet and outlet, are controlled by means of pumps and needle valves, and are measured by differential and absolute pressure transducers. The clear epoxy cast of the natural fracture preserves the geometry of the fracture and permits visual observation of phase distributions. The fracture aperture distribution can be estimated by filling the fracture with a dyed liquid, and making pointwise measurements of the intensity of transmitted light. A set of two-phase flow experiments has been performed which has proven the viability of the basic experimental design, while also suggesting further improvements in the apparatus. Preliminary measurements are presented for single-phase permeability to liquid, and for relative permeabilities in simultaneous flow of liquid and gas.
Download or read book A Stratified Percolation Model for Saturated and Unsaturated Flow Through Natural Fractures written by and published by . This book was released on 1990 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: The geometry of the asperities of contact between the two surfaces of a fracture and of the adjacent void spaces determines fluid flow through a fracture and the mechanical deformation across a fracture. Heuristically we have developed a stratified continuum percolation model to describe this geometry based on a fractal construction that includes scale invariance and correlation of void apertures. Deformation under stress is analyzed using conservation of rock volume to correct for asperity interpenetration. Single phase flow is analyzed using a critical path along which the principal resistance is a result of laminar flow across the critical neck in this path. Results show that flow decreases with apparent aperture raised to a variable power greater than cubic, as is observed in flow experiments on natural fractures. For two phases, flow of the non-wetting phase is likewise governed by the critical neck along the critical path of largest aperture but flow of the wetting phase is governed by tortuosity. 17 refs., 10 figs.
Download or read book LABORATORY EXPERIMENTS ON HEAT DRIVEN TWO PHASE FLOWS IN NATURAL AND ARTIFICIAL ROCK FRACTURES written by and published by . This book was released on 1998 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Water flow in partially saturated fractures under thermal drive may lead to fast flow along preferential localized pathways and heat pipe conditions. At the potential high-level nuclear waste repository at Yucca Mountain, water flowing in fast pathways may ultimately contact waste packages and transport radionuclides to the accessible environment. Sixteen experiments were conducted to visualize heat-driven liquid flow in fracture models that included (1) assemblies of roughened glass plates, (2) epoxy replicas of rock fractures, and (3) a fractured specimen of Topopah Spring tuff. Continuous rivulet flow was observed for high liquid flow rates, intermittent rivulet flow and drop flow for intermediate flow rates, and film flow for lower flow rates and wide apertures. Heat pipe conditions (vapor-liquid counterflow with phase change) were identified in five of the seven experiments in which spatially resolved thermal monitoring was performed, but not when liquid-vapor counterflow was hindered by very narrow apertures, and when inadequate working fluid volume was used.
