Effects of Water Injection Into Fractured Geothermal Reservoirs
Effects of Water Injection Into Fractured Geothermal Reservoirs

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Publisher:

Published: 1982

Total Pages:

ISBN-13:

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Reinjection of water into fractured geothermal reservoirs holds potential both for improvement and degradation of total energy recovery. The replacement of reservoir fluid can mean support of placement of reservoir pressures and also more efficient thermal energy recovery, but at the same time the premature invasion of reinjected water back into production wells through high permeability fractures can reduce discharge enthalpy and hence deliverability and useful energy output. Increases in reservoir pressure and maintenance of field output have been observed in operating fields, but unfortunately so too have premature thermal breakthroughs. The design of reinjection schemes, therefore, requires careful investigation into the likely effects, using field experimentation. This paper summarizes field experience with reinjection around the world, with the intention of elucidating characteristics of possible problems. The results summarized in this paper fall into three categories of interest: permeability changes dye to injection (both increases and decreases); the path followed by injected water (as indicated by tracer tests); and the thermal and hydraulic influences of injection on the reinjection well itself and on surrounding producers. [DJE-2005].

Injection Into a Fractured Geothermal Reservoir
Injection Into a Fractured Geothermal Reservoir

Author:

Publisher:

Published: 1980

Total Pages:

ISBN-13:

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A detailed study is made on the movement of the thermal fronts in the fracture and in the porous medium when 100°C water is injected into a 300°C geothermal reservoir with equally spaced horizontal fractures. Numerical modeling calculations were made for a number of thermal conductivity values, as well as different values of the ratio of fracture and rock medium permeabilities. One important result is an indication that although initially, the thermal front in the fracture moves very fast relative to the front in the porous medium as commonly expected, its speed rapidly decreases. At some distance from the injection well the thermal fronts in the fracture and the porous medium coincide, and from that point they advance together. The implication of this result on the effects of fractures on reinjection into geothermal reservoirs is discussed.

Geothermal Reservoir Engineering
Geothermal Reservoir Engineering

Author: Malcolm Alister Grant

Publisher: Academic Press

Published: 2011-04-01

Total Pages: 379

ISBN-13: 0123838819

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As nations alike struggle to diversify and secure their power portfolios, geothermal energy, the essentially limitless heat emanating from the earth itself, is being harnessed at an unprecedented rate. For the last 25 years, engineers around the world tasked with taming this raw power have used Geothermal Reservoir Engineering as both a training manual and a professional reference. This long-awaited second edition of Geothermal Reservoir Engineering is a practical guide to the issues and tasks geothermal engineers encounter in the course of their daily jobs. The book focuses particularly on the evaluation of potential sites and provides detailed guidance on the field management of the power plants built on them. With over 100 pages of new material informed by the breakthroughs of the last 25 years, Geothermal Reservoir Engineering remains the only training tool and professional reference dedicated to advising both new and experienced geothermal reservoir engineers. - The only resource available to help geothermal professionals make smart choices in field site selection and reservoir management - Practical focus eschews theory and basics- getting right to the heart of the important issues encountered in the field - Updates include coverage of advances in EGS (enhanced geothermal systems), well stimulation, well modeling, extensive field histories and preparing data for reservoir simulation - Case studies provide cautionary tales and best practices that can only be imparted by a seasoned expert

Analytic Element Modeling of Groundwater Flow
Analytic Element Modeling of Groundwater Flow

Author: H. M. Haitjema

Publisher: Elsevier

Published: 1995-09-20

Total Pages: 407

ISBN-13: 0080499104

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Modeling has become an essential tool for the groundwater hydrologist. Where field data is limited, the analytic element method (AEM) is rapidly becoming the modeling method of choice, especially given the availability of affordable modeling software. Analytic Element Modeling of Groundwater Flow provides all the basics necessary to approach AEM successfully, including a presentation of fundamental concepts and a thorough introduction to Dupuit-Forchheimerflow. This book is unique in its emphasis on the actual use of analytic element models. Real-world examples complement material presented in the text. An educational version of the analytic element program GFLOW is included to allow the reader to reproduce the various solutions to groundwater flow problems discussed in the text. Researchers and graduate students in groundwater hydrology, geology, andengineering will find this book an indispensable resource. * * Provides a fundamental introduction to the use of the analytic element method. * Offers a step-by-step approach to groundwater flow modeling. * Includes an educational version of the GFLOW modeling software.

The Long Term Observed Effect of Air and Water Injection Into a Fracture Hydrothermal System
The Long Term Observed Effect of Air and Water Injection Into a Fracture Hydrothermal System

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Publisher:

Published: 1992

Total Pages:

ISBN-13:

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Injection of atmospheric air mixed with waste reinjection liquid, has been occurring since 1982 at the Los Azufres, Mexico volcanic hydrothermal system. Several chemical and thermodynamical evidences show that air injection into this fractured geothermal field, could be considered as a long term natural tracer test. Nitrogen and Argon separated from the air mixture migrate from reinjection wells to production zones following preferential paths closely related to high permeability conduits. These paths can be detected, looking into the N2 solubility evolution of production wells. The anisotropic nature of the fractured volcanic rock, would demand considerably amounts of artificial tracer in order to be detected at the producing wells, specially when fluid extraction is low. This explains the unsuccessful recovery of the artificial tracer tests performed in past years at Tejamaniles, the southern field's sector. On the other hand, chloride concentrations and other salts, are increasing in the liquid produced by the oldest wells of the sector.

Rock Fractures and Fluid Flow
Rock Fractures and Fluid Flow

Author: National Research Council

Publisher: National Academies Press

Published: 1996-08-27

Total Pages: 568

ISBN-13: 0309049962

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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.