Download or read book The Thermal Conductivity of Rock Under Hydrothermal Conditions written by and published by . This book was released on 1996 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The thermal conductivities of most major rock-forming minerals vary with both temperature and confining pressure, leading to substantial changes in the thermal properties of some rocks at the high temperatures characteristic of geothermal systems. In areas with large geothermal gradients, the successful use of near-surface heat flow measurements to predict temperatures at depth depends upon accurate corrections for varying thermal conductivity. Previous measurements of the thermal conductivity of dry rock samples as a function of temperature were inadequate for porous rocks and susceptible to thermal cracking effects in nonporous rocks. We have developed an instrument for measuring the thermal conductivity of water-saturated rocks at temperatures from 20 to 350 °C and confining pressures up to 100 MPa. A transient line-source of heat is applied through a needle probe centered within the rock sample, which in turn is enclosed within a heated pressure vessel with independent controls on pore and confining pressure. Application of this technique to samples of Franciscan graywacke from The Geysers reveals a significant change in thermal conductivity with temperature. At reservoir-equivalent temperatures of 250 °C, the conductivity of the graywacke decreases by approximately 25% relative to the room temperature value. Where heat flow is constant with depth within the caprock overlying the reservoir, this reduction in conductivity with temperature leads to a corresponding increase in the geothermal gradient. Consequently, reservoir temperature are encountered at depths significantly shallower than those predicted by assuming a constant temperature gradient with depth. We have derived general equations for estimating the thermal conductivity of most metamorphic and igneous rocks and some sedimentary rocks at elevated temperature from knowledge of the room temperature thermal conductivity. Application of these equations to geothermal exploration should improve estimates of subsurface temperatures derived from heat flow measurements.

Download or read book Thermal Conductivity of Rock written by Robert L. Marovelli and published by . This book was released on 1965 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Thermal Properties and Temperature Related Behavior of Rock Fluid Systems written by W.H. Somerton and published by Elsevier. This book was released on 1992-03-02 with total page 267 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book brings together for the first time the results of research on the thermal properties and temperature-related behavior of rocks with their contained fluids, under subsurface environmental conditions. These data are of increasing importance with increased application of underground processes involving high temperature and, in some cases, low temperature environments. Some of the important processes are described in which thermal data are needed. Chapters deal with thermal properties of rocks, including heat capacities, thermal conductivities and thermal diffusivities under conditions simulating subsurface environments. Discussion about the difficulty in measuring thermal properties of rock/fluid systems is included along with newly-developed models for predicting thermal properties from more-easily measured properties. The effects of thermal reactions in rocks, differential thermal expansion, and thermal alterations are discussed in separate chapters. The effects of temperature on rock properties, as distinct from the irreversible effects of heating, are reviewed. Lastly the book deals with wellbore applications of thermal and high-temperature behavior of rocks and methods of deducing thermal properties from geophysical logs run in boreholes. Appendices include thermal units conversion factors and thermal properties of some typical reservoir rocks and fluids.

Download or read book Rock Thermal Conductivity at the Cap Rock and Initial Conditions in Two phase Volcanic Hydrothermal Systems written by and published by . This book was released on 1993 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Numerical experiments are performed to investigate the rock thermal conductivity influence in the formation of the thermodynamic initial conditions of two-phase systems located in volcanic rocks. These systems exhibit pressure and temperature profiles characterized by a sudden change or discontinuity in their vertical gradients. Vapor dominated, two-phase fluids are found at the upper reservoir's levels. Liquid is the dominated phase within the layers below some critical point. Numerical results presented in this paper, suggest that the vertical location of this point of discontinuity be controlled by the thermal conductivity existing between the limit of the reservoir and the caprock. Too high values could originate liquid dominated reservoirs. Small values would be at the origin of vapor dominated reservoirs. A characteristic middle value could be responsible for the formation of a counter flow mechanism originating the initial conditions observed at some locations of the Los Azufres, Mexico, geothermal field.

Download or read book Fundamentals of Rock Physics written by Nikolai Bagdassarov and published by Cambridge University Press. This book was released on 2021-12-09 with total page 566 pages. Available in PDF, EPUB and Kindle. Book excerpt: Rock physics encompasses practically all aspects of solid and fluid state physics. This book provides a unified presentation of the underlying physical principles of rock physics, covering elements of mineral physics, petrology and rock mechanics. After a short introduction on rocks and minerals, the subsequent chapters cover rock density, porosity, stress and strain relationships, permeability, poroelasticity, acoustics, conductivity, polarizability, magnetism, thermal properties and natural radioactivity. Each chapter includes problem sets and focus boxes with in-depth explanations of the physical and mathematical aspects of underlying processes. The book is also supplemented by online MATLAB exercises to help students apply their knowledge to numerically solve rock physics problems. Covering laboratory and field-based measurement methods, as well as theoretical models, this textbook is ideal for upper-level undergraduate and graduate courses in rock physics. It will also make a useful reference for researchers and professional scientists working in geoscience and petroleum engineering.

Download or read book Hydrothermal Reactions for Materials Science and Engineering written by S. Somiya and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 503 pages. Available in PDF, EPUB and Kindle. Book excerpt: According to the late Professor Emeritus Seitaro Tsuboi,l the word 'hydrothermal' was used as early as 1849 by a British geologist, Sir Roderick Murchison (1792-187 I), in relation to the action of heated water in bringing about change in the earth's crust. The term abounds in later geological literature, and is most frequently met in connection with the processes that take place at a stage near the closing in the course of consolidation of magma. When a cooling magma reaches that stage, the residual liquid contains a large proportion of volatile components, chiefly water, and further cooling results in the formation of minerals of special interest or ore-deposits. A great concern of Tsuboi's as a petrologist was to elucidate the details of the nature of various actions involved in these 'hydrothermal processes', of which little was known. It is remarkable that, in the last few decades, extensive high-temperature and high-pressure experiments, in which water plays an important role, have become practicable in laboratories, owing to the development of new apparatus and new methods. As a result, the knowledge essential to the elucidation of 'hydrothermal processes' has been improved, but is still far from complete.

Download or read book Thermo Physical Properties of Rocks Special Reference to Deccan Trap Basalts written by S.R. Sharma and published by Allied Publishers. This book was released on 2015-01-05 with total page 181 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book includes the basics and published and unpublished data on thermal properties, density-porosity-permeability, electrical properties, seismic properties, magnetic properties and natural radioactivity at NTP and for some properties at elevated temperatures for crust-mantle rocks and minerals with special reference to Deccan Basalts, their units, measurement techniques, co-relation with other geophysical parameters and applications. The writing of the book is sponsored by the Department of Science and Technology (DST) New Delhi for the benefit of the students, research scholars and scientists.

Download or read book Geothermal Energy Update written by and published by . This book was released on 1976 with total page 668 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book High Temperature Thermal Conductivity of Six Rocks written by D. R. Stephens and published by . This book was released on 1963 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Thermal Conductivity of Fluid Saturated Rocks at Elevated Pressures and Termperatures written by Jeevan Anand and published by . This book was released on 1971 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Workshop Report written by and published by . This book was released on 1997 with total page 552 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Thermal Conductivity of Rocks Associated with Energy Extraction from Hot Dry Rock Geothermal Systems written by and published by . This book was released on 1978 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Results of thermal conductivity measurements are given for 14 drill core rock samples taken from two exploratory HDR geothermal wellbores (maximum depth of 2929 m (9608 ft) drilled into Precambrian granitic rock in the Jemez Mountains of northern New Mexico. These samples have been petrographically characterized and in general represent fresh competent Precambrian material of deep origin. Thermal conductivities, modal analyses, and densities are given for all core samples studied under dry and water-saturated conditions. Additional measurements are reported for several sedimentary rocks encountered in the upper 760 m (2500 ft) of that same region. A cut-bar thermal conductivity comparator and a transient needle probe were used for the determinations with fused quartz and Pyroceram 9606 as the standards. The maximum temperature range of the measurements was from the ice point to 250°C. The measurements on wet, water-saturated rock were limited to the temperature range below room temperature. Conductivity values of the dense core rock samples were generally within the range from 2 to 2.9 W/mK at 200°C. Excellent agreement was achieved between these laboratory measurements of thermal conductivity and those obtained by in situ measurements used in the HDR wellbores. By using samples of sufficient thickness to provide a statistically representative heat flow path, no difference between conductivity values and their temperature coefficients for orthogonal directions (heat flow parallel or perpendicular to core axis) was observed. This isotropic behavior was even found for highly foliated gneissic specimens. Estimates of thermal conductivity based on a composite dispersion analysis utilizing pure minerallic phase conductivities and detailed modal analyses usually agreed to within 9 percent of the experimental values.

Download or read book Federal Geothermal Research Program Update Fiscal Year 1995 written by Geothermal Research Program (U.S.) and published by . This book was released on 1996 with total page 492 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book U S Geological Survey Circular written by and published by . This book was released on 1933 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Geological Survey Circular written by and published by . This book was released on 1983 with total page 954 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Water Resources Division in the 1980 s written by E. C. T. Chao and published by . This book was released on 1983 with total page 378 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Rock Mechanics and Rock Engineering From the Past to the Future written by Reşat Ulusay and published by CRC Press. This book was released on 2016-11-18 with total page 1371 pages. Available in PDF, EPUB and Kindle. Book excerpt: Rock Mechanics and Rock Engineering: From the Past to the Future contains the contributions presented at EUROCK2016, the 2016 International Symposium of the International Society for Rock Mechanics (ISRM 2016, Ürgüp, Cappadocia Region, Turkey, 29-31 August 2016). The contributions cover almost all aspects of rock mechanics and rock engineering from theories to engineering practices, emphasizing the future direction of rock engineering technologies. The 204 accepted papers and eight keynote papers, are grouped into several main sections: - Fundamental rock mechanics - Rock properties and experimental rock mechanics - Analytical and numerical methods in rock engineering - Stability of slopes in civil and mining engineering - Design methodologies and analysis - Rock dynamics, rock mechanics and rock engineering at historical sites and monuments - Underground excavations in civil and mining engineering - Coupled processes in rock mass for underground storage and waste disposal - Rock mass characterization - Petroleum geomechanics - Carbon dioxide sequestration - Instrumentation-monitoring in rock engineering and back analysis - Risk management, and - the 2016 Rocha Medal Lecture and the 2016 Franklin Lecture Rock Mechanics and Rock Engineering: From the Past to the Future will be of interest to researchers and professionals involved in the various branches of rock mechanics and rock engineering. EUROCK 2016, organized by the Turkish National Society for Rock Mechanics, is a continuation of the successful series of ISRM symposia in Europe, which began in 1992 in Chester, UK.