Three-Dimensional Geologic Characterization of Geothermal Systems

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Book Synopsis Three-Dimensional Geologic Characterization of Geothermal Systems by :

Download or read book Three-Dimensional Geologic Characterization of Geothermal Systems written by and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Geothermal systems in the Great Basin, USA, are controlled by a variety of fault intersection and fault interaction areas. Understanding the specific geometry of the structures most conducive to geothermal circulation is crucial in order to both mitigate the costs of geothermal exploration (especially drilling) and to identify blind geothermal systems (no surface expression). Astor Pass, Nevada, one such blind geothermal system, lies near the boundary between two distinct structural domains, the Walker Lane and the Basin and Range, and exhibits characteristics of each setting. Both northwest-striking, left-stepping dextral faults of the Walker Lane and kinematically linked northerly striking normal faults associated with the Basin and Range are present at Astor Pass. Previous studies identified a blind geothermal system controlled by the intersection of northwest-striking dextral and north-northwest-striking normal faults. Wells drilled into the southwestern quadrant of the fault intersection yielded 94°C fluids, with geothermometers suggesting significantly higher maximum temperatures. Additional data, including reprocessed 2D seismic data and petrologic analysis of well cuttings, were integrated with existing and reinterpreted geologic maps and cross-sections to aid construction of a 3D geologic model. This comprehensive 3D integration of multiple data sets allows characterization of the structural setting of the Astor Pass blind geothermal system at a level of detail beyond what independent data interpretation can provide. Our analysis indicates that the blind geothermal system is controlled by two north- to northwest-plunging fault intersections.

Three-Dimensional Geologic Characterization of a Great Basin Geothermal System

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Book Synopsis Three-Dimensional Geologic Characterization of a Great Basin Geothermal System by :

Download or read book Three-Dimensional Geologic Characterization of a Great Basin Geothermal System written by and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Great Basin, western USA, exhibits anomalously high heat flow (~75±5 mWm-2) and active faulting and extension, resulting in ~430 known geothermal systems. Recent studies have shown that steeply dipping normal faults in transtensional pull-aparts are a common structural control of these Great Basin geothermal systems. The Astor Pass blind (no surface expression) geothermal system, Nevada, lies along the boundary between the Basin and Range to the east and the Walker Lane to the west. Across this boundary, strain is transferred from dextral shear in the Walker Lane to west-northwest directed extension in the Basin and Range, resulting in a transtensional setting consisting of both northwest-striking, left-stepping dextral faults and northerly striking normal faults. Previous studies indicate that Astor Pass was controlled by the intersection of a northwest-striking dextral normal fault and north-northwest striking normal-dextral fault bounding the western side of the Terraced Hills. Drilling (to ~1200 m) has revealed fluid temperatures of ~94°C, confirming a blind geothermal system. Expanding upon previous work and employing interpretation of 2D seismic reflection data, additional detailed geologic mapping, and well cuttings analysis, a 3-dimensional geologic model of the Astor Pass geothermal system was constructed. The 3D model indicates a complex interaction/intersection area of three discrete fault zones: a northwest-striking dextral-normal fault, a north-northwest-striking normal-dextral fault, and a north-striking west-dipping normal fault. These two discrete, critically-stressed intersection areas plunge moderately to steeply to the NW-NNW and probably act as conduits for upwelling geothermal fluids.

3-Dimensional Geologic Modeling Applied to the Structural Characterization of Geothermal Systems

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Book Synopsis 3-Dimensional Geologic Modeling Applied to the Structural Characterization of Geothermal Systems by :

Download or read book 3-Dimensional Geologic Modeling Applied to the Structural Characterization of Geothermal Systems written by and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Geothermal systems in the Great Basin, USA, are controlled by a variety of fault intersection and fault interaction areas. Understanding the specific geometry of the structures most conducive to broad-scale geothermal circulation is crucial to both the mitigation of the costs of geothermal exploration (especially drilling) and to the identification of geothermal systems that have no surface expression (blind systems). 3-dimensional geologic modeling is a tool that can elucidate the specific stratigraphic intervals and structural geometries that host geothermal reservoirs. Astor Pass, NV USA lies just beyond the northern extent of the dextral Pyramid Lake fault zone near the boundary between two distinct structural domains, the Walker Lane and the Basin and Range, and exhibits characteristics of each setting. Both northwest-striking, left-stepping dextral faults of the Walker Lane and kinematically linked northerly striking normal faults associated with the Basin and Range are present. Previous studies at Astor Pass identified a blind geothermal system controlled by the intersection of west-northwest and north-northwest striking dextral-normal faults. Wells drilled into the southwestern quadrant of the fault intersection yielded 94°C fluids, with geothermometers suggesting a maximum reservoir temperature of 130°C. A 3-dimensional model was constructed based on detailed geologic maps and cross-sections, 2-dimensional seismic data, and petrologic analysis of the cuttings from three wells in order to further constrain the structural setting. The model reveals the specific geometry of the fault interaction area at a level of detail beyond what geologic maps and cross-sections can provide.

3D Characterization of a Great Basin Geothermal System

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ISBN 13 :
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Book Synopsis 3D Characterization of a Great Basin Geothermal System by :

Download or read book 3D Characterization of a Great Basin Geothermal System written by and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Great Basin exhibits both anomalously high heat flow (~75±5 mWm-2) and active faulting and extension resulting in robust geothermal activity. There are ~430 known geothermal systems in the Great Basin, with evidence suggesting that undiscovered blind geothermal systems may actually represent the majority of geothermal activity. These systems employ discrete fault intersection/interaction areas as conduits for geothermal circulation. Recent studies show that steeply dipping normal faults with step-overs, fault intersections, accommodation zones, horse-tailing fault terminations and transtensional pull-aparts are the most prominent structural controls of Great Basin geothermal systems. These fault geometries produce sub-vertical zones of high fault and fracture density that act as fluid flow conduits. Structurally controlled fluid flow conduits are further enhanced when critically stressed with respect to the ambient stress conditions. The Astor Pass blind geothermal system, northwestern Nevada, lies along the boundary between the Basin and Range to the east and the Walker Lane to the west. Along this boundary, strain is transferred from dextral shear in the Walker Lane to west-northwest directed extension in the Basin and Range. As such, the Astor Pass area lies in a transtensional setting consisting of both northwest-striking, left-stepping dextral faults and more northerly striking normal faults. The Astor Pass tufa tower implies the presence of a blind geothermal system. Previous studies suggest that deposition of the Astor Pass tufa was controlled by the intersection of a northwest-striking dextral normal fault and north-northwest striking normal fault. Subsequent drilling (to ~1200 m) has revealed fluid temperatures of ~94°C, confirming the presence of a blind geothermal system at Astor Pass. Expanding upon previous work and employing additional detailed geologic mapping, interpretation of 2D seismic reflection data and analysis of well cuttings, a 3-dimensional geologic model of the Astor Pass blind geothermal system was constructed. The 3D structural framework indicates that the Pleistocene tufa is associated with three discrete fault zones whose intersections plunge moderately to steeply NW-NNW. These critically stressed fault intersections act as conduits for upwelling geothermal fluids.

Characterization of Ore-Forming Systems from Geological, Geochemical and Geophysical Studies

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Publisher : Geological Society of London
ISBN 13 : 1786203138
Total Pages : 412 pages
Book Rating : 4.7/5 (862 download)

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Book Synopsis Characterization of Ore-Forming Systems from Geological, Geochemical and Geophysical Studies by : K. Gessner

Download or read book Characterization of Ore-Forming Systems from Geological, Geochemical and Geophysical Studies written by K. Gessner and published by Geological Society of London. This book was released on 2018-08-07 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt: Economically viable concentrations of mineral resources are uncommon in Earth’s crust. Most ore deposits that were mined in the past or are currently being extracted were found at or near Earth’s surface, often serendipitously. To meet the future demand for mineral resources, exploration success hinges on identifying targets at depth. Achieving this requires accurate and informed models of the Earth's crust that are consistent with all available geological, geochemical and geophysical information, paired with an understanding of how ore-forming systems relate to Earth’s evolving structure. Contributions to this volume address the future resources challenge by (i) applying advanced microscale geochemical detection and characterization methods, (ii) introducing more rigorous 3D Earth models, (iii) exploring critical behaviour and coupled processes, (iv) evaluating the role of geodynamic and tectonic setting and (v) applying 3D structural models to characterize specific ore-forming systems.

Three Dimensional Characterization of the Astor Pass Geothermal System, Washoe County, Nevada

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ISBN 13 :
Total Pages : 204 pages
Book Rating : 4.:/5 (868 download)

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Book Synopsis Three Dimensional Characterization of the Astor Pass Geothermal System, Washoe County, Nevada by : Brett Andrew Mayhew

Download or read book Three Dimensional Characterization of the Astor Pass Geothermal System, Washoe County, Nevada written by Brett Andrew Mayhew and published by . This book was released on 2013 with total page 204 pages. Available in PDF, EPUB and Kindle. Book excerpt: Seismic reflection interpretation, detailed analysis of well cuttings, stress field analysis, and construction of a 3D geologic model have been used in the characterization of the stratigraphic and structural framework of the Astor Pass geothermal area. The Astor Pass geothermal system resides in the northwestern part of the Pyramid Lake Paiute Reservation, on the margins of the Basin and Range and Walker Lane tectonic provinces in northwestern Nevada. The area is primarily comprised of middle Miocene Pyramid sequence volcanic and sedimentary rocks, nonconformably overlying Mesozoic metamorphic and granitic rocks. Previous investigations of the Astor Pass area focused on the general structural setting, argillic alteration of the Miocene rocks, lineations of Quaternary tufa mounds, and a shallow temperature survey. Wells drilled at Astor Pass show reservoir temperatures of ~95°C. Analyses of well cuttings show a ~1 km thick section of highly transmissive and permeable Miocene volcanic and sedimentary rocks overlying a relatively impermeable granodiorite and metavolcanic basement. Seismic reflection interpretation confirms a high fault density in the geothermal area, with many possible fluid pathways penetrating into the Mesozoic basement. Stress field analysis using borehole breakout data from the wells reveals a regionally consistent west-northwest-trending least principal stress direction, with stress magnitudes reflecting a complex transtensional faulting regime. A lack of data on the mechanical properties of the reservoir rocks, such as strength parameters, results in some ambiguity in the calculated stress field. However, reasonable assumptions regarding these variables produced both a normal faulting and strike-slip faulting regime. Taking into consideration both possible stress regimes, the stress data were utilized in a slip and dilation tendency analysis of the fault model, which suggests two promising fault areas that would control the upwelling geothermal fluid. The first is a moderately dipping fault intersection plunging to the northwest away from the prominent tufa mound in the center of Astor Pass. The second subvertical fault intersection is directly beneath the tufa mound and closest to the highest temperatures measured in the geothermal system. Both of these fault intersection areas show positive attributes for controlling geothermal fluids, but hydrologic tests show the 1 km thick volcanic section is highly transmissive. Thus, focused upwellings along discrete fault conduits may be confined to the Mesozoic basement before fluids diffuse into the Miocene volcanic reservoir above. Astor Pass contains a moderate temperature geothermal system with a large, diffuse reservoir in the Miocene volcanic rocks, capable of sustaining high pump rates. Understanding this type of system may be helpful in exploring for large, permeable reservoirs in deep sedimentary basins of the eastern Basin and Range and the highly fractured volcanic geothermal reservoirs in the Snake River Plain and elsewhere.

Three-Dimensional Geothermal Fairway Mapping

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ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (957 download)

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Book Synopsis Three-Dimensional Geothermal Fairway Mapping by :

Download or read book Three-Dimensional Geothermal Fairway Mapping written by and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Elevated permeability along fault systems provides pathways for circulation of geothermal fluids. Accurate location of such fluid flow pathways in the subsurface is crucial to future geothermal development in order to both accurately assess resource potential and mitigate drilling costs by increasing drilling success rates. Employing a variety of surface and subsurface data sets, we present detailed 3D geologic analyses of two Great Basin geothermal systems, the actively producing Brady's geothermal system and a 'greenfield' geothermal prospect at Astor Pass, Nevada. 3D modeling provides the framework for quantitative structural analyses. We combine 3D slip and dilation tendency analysis along fault zones and calculations of fault intersection density in the two geothermal systems with the locations of lithologies capable of supporting dense, interconnected fracture networks. The collocation of these permeability promoting characteristics with elevated heat represent geothermal 'fairways', areas with ideal conditions for geothermal fluid flow. Location of geothermal fairways at high resolution in 3D space can help to mitigate the costs of geothermal exploration by providing discrete drilling targets and data-based evaluations of reservoir potential.

3D Magnetotelluric Characterization of the COSO GeothermalField

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ISBN 13 :
Total Pages : pages
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Book Synopsis 3D Magnetotelluric Characterization of the COSO GeothermalField by : Philip E. Wannamaker

Download or read book 3D Magnetotelluric Characterization of the COSO GeothermalField written by Philip E. Wannamaker and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Knowledge of the subsurface electrical resistivity/conductivity can contribute to a better understanding of complex hydrothermal systems, typified by Coso geothermal field, through mapping the geometry (bounds and controlling structures) over existing production. Three-dimensional magnetotelluric (MT) inversion is now an emerging technology for characterizing the resistivity structures of complex geothermal systems. The method appears to hold great promise, but histories exploiting truly 3D inversion that demonstrate the advantages that can be gained by acquiring and analyzing MT data in three dimensions are still few in number. This project will address said issue, by applying 3D MT forward modeling and inversion to a MT data set acquired over the Coso geothermal field. The goal of the project is to provide the capability to image large geothermal reservoirs in a single self-consistent model. Initial analysis of the Coso MT data has been carried out using 2D MT imaging technology to construct an initial 3D resistivity model from a series of 2D resistivity images obtained using the inline electric field measurements (Zxy impedance elements) along different measurement transects. This model will be subsequently refined through a 3D inversion process. The initial 3D resistivity model clearly shows the controlling geological structures possibly influencing well production at Coso. The field data however, also show clear three dimensionality below 1 Hz, demonstrating the limitations of 2D resistivity imaging. The 3D MT predicted data arising from this starting model show good correspondence in dominant components of the impedance tensor (Zxy and Zyx) above 1Hz. Below 1 Hz there is significant differences between the field data and the 2D model data.

Advanced Methods for Interpreting Geological and Geophysical Data

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Publisher : Frontiers Media SA
ISBN 13 : 2832551505
Total Pages : 500 pages
Book Rating : 4.8/5 (325 download)

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Book Synopsis Advanced Methods for Interpreting Geological and Geophysical Data by : Ahmed M. Eldosouky

Download or read book Advanced Methods for Interpreting Geological and Geophysical Data written by Ahmed M. Eldosouky and published by Frontiers Media SA. This book was released on 2024-07-08 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt: The introduction and application of advanced geological and geophysical methods can solve many problems related to geoscience. This Research Topic gives a thorough treatment of the interpretation of geological and geophysical data through advanced techniques and integrated approaches. It aims to create a more reliable integration of various geological and geophysical data in an exploration and new findings context weighing the strengths and limitations of the various methods in order to develop geophysical and geological models. It will also focus on the interpretation techniques for evaluating structural and sedimentological (stratigraphical) processes with applications within resource exploration, geohazards, seismology, seabed ecology and global climate.

Geological Monitoring

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Publisher : Geological Society of America
ISBN 13 : 0813760321
Total Pages : 316 pages
Book Rating : 4.8/5 (137 download)

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Book Synopsis Geological Monitoring by : Rob Young

Download or read book Geological Monitoring written by Rob Young and published by Geological Society of America. This book was released on 2009 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Geologic Monitoring is a practical, nontechnical guide for land managers, educators, and the public that synthesizes representative methods for monitoring short-term and long-term change in geologic features and landscapes. A prestigious group of subject-matter experts has carefully selected methods for monitoring sand dunes, caves and karst, rivers, geothermal features, glaciers, nearshore marine features, beaches and marshes, paleontological resources, permafrost, seismic activity, slope movements, and volcanic features and processes. Each chapter has an overview of the resource; summarizes features that could be monitored; describes methods for monitoring each feature ranging from low-cost, low-technology methods (that could be used for school groups) to higher cost, detailed monitoring methods requiring a high level of expertise; and presents one or more targeted case studies."--Publisher's description.

3D Magnetotelluic Characterization of the Coso GeothermalField

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ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (727 download)

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Book Synopsis 3D Magnetotelluic Characterization of the Coso GeothermalField by :

Download or read book 3D Magnetotelluic Characterization of the Coso GeothermalField written by and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Electrical resistivity may contribute to progress inunderstanding geothermal systems by imaging the geometry, bounds andcontrolling structures in existing production, and thereby perhapssuggesting new areas for field expansion. To these ends, a dense grid ofmagnetotelluric (MT) stations plus a single line of contiguous bipolearray profiling has been acquired over the east flank of the Cosogeothermal system. Acquiring good quality MT data in producing geothermalsystems is a challenge due to production related electromagnetic (EM)noise and, in the case of Coso, due to proximity of a regional DCintertie power transmission line. To achieve good results, a remotereference completely outside the influence of the dominant source of EMnoise must be established. Experimental results so far indicate thatemplacing a reference site in Amargosa Valley, NV, 65 miles from the DCintertie, isstill insufficient for noise cancellation much of the time. Even though the DC line EM fields are planar at this distance, theyremain coherent with the nonplanar fields in the Coso area hence remotereferencing produces incorrect responses. We have successfully unwrappedand applied MT times series from the permanent observatory at Parkfield, CA, and these appear adequate to suppress the interference of thecultural EM noise. The efficacy of this observatory is confirmed bycomparison to stations taken using an ultra-distant reference site eastof Socorro, NM. Operation of the latter reference was successful by usingfast ftp internet communication between Coso Junction and the New MexicoInstitute of Mining and Technology, using the University of Utah site asintermediary, and allowed referencing within a few hours of datadownloading at Coso. A grid of 102 MT stations was acquired over the Cosogeothermal area in 2003 and an additional 23 stations were acquired toaugment coverage in the southern flank of the first survey area in 2005. These data have been inverted to a fully three-dimensional conductivitymodel. Initial analysis of the Coso MT data was carried out using 2D MTimaging. An initial 3D conductivity model was constructed from a seriesof 2D resistivity images obtained using the inline electric fieldmeasurements (Zyx impedance elements) along several measurementtransects. This model was then refined through a 3D inversion process. This model shows the controlling geological structures possiblyinfluencing well production at Coso and correlations with mapped surfacefeatures such as faults and regional geoelectric strike. The 3D modelalso illustrates the refinement in positioning of conductivity contactswhen compared to isolated 2D inversion transects. The conductivity modelhas also been correlated with microearthquake locations, well fluidproduction intervals and most importantly with an acoustic and shearvelocity model derived by Wu and Lees (1999). This later correlationshows the near-vertical high conductivity structure on the eastern flankof the producing field is also a zone of increased acoustic velocity andincreased Vp/Vs ratio bounded by mapped fault traces. South of theDevil's Kitchen is an area of high geothermal well density, where highlyconductive near surface material is interpreted as a clay cap alterationzone manifested from the subsurface geothermal fluids and relatedgeochemistry. Beneath the clay cap, however, the conductivity isnondescript, whereas the Vp/Vs ratio is enhanced over the productionintervals. It is recommended that more MT data sites be acquired to thesouthwest of the Devil's Kitchen area to better refine the conductivitymodel in that area.

Geothermal Energy Update

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Publisher :
ISBN 13 :
Total Pages : 444 pages
Book Rating : 4.3/5 (243 download)

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Book Synopsis Geothermal Energy Update by :

Download or read book Geothermal Energy Update written by and published by . This book was released on 1978-12 with total page 444 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Computational Geo-Electromagnetics

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Publisher :
ISBN 13 : 0128196319
Total Pages : 462 pages
Book Rating : 4.1/5 (281 download)

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Book Synopsis Computational Geo-Electromagnetics by : Viacheslav V. Spichak

Download or read book Computational Geo-Electromagnetics written by Viacheslav V. Spichak and published by . This book was released on 2020-02 with total page 462 pages. Available in PDF, EPUB and Kindle. Book excerpt: Computational Geo-Electromagnetics: Methods, Models, and Forecasts, Volume Five in the Computational Geophysics series, is devoted to techniques for building of geoelectrical models from electromagnetic data, featuring Bayesian statistical analysis and neural network algorithms. These models are applied to studying the geoelectrical structure of famous volcanoes (i.e., Vesuvio, Kilauea, Elbrus, Komagatake, Hengill) and geothermal zones (i.e., Travale, Italy; Soultz-sous-Forets, Elsace). Methodological recommendations are given on electromagnetic sounding of faults as well as geothermal and hydrocarbon reservoirs. Techniques for forecasting of petrophysical properties from the electrical resistivity as proxy parameter are also considered. Computational Geo-Electromagnetics: Methods, Models, and Forecasts offers techniques and algorithms for building geoelectrical models under conditions of rare or irregularly distributed EM data and/or lack of prior geological and geophysical information. This volume also includes methodological guidelines on interpretation of electromagnetic sounding data depending on goals of the study. Finally, it details computational algorithms for using electrical resistivity for properties beyond boreholes. Provides algorithms for inversion of incomplete, rare or irregularly distributed EM data Features methodological issues of building geoelectrical models Offers techniques for retrieving petrophysical properties from EM sounding data and well logs

Advancements in 3D Structural Analysis of Geothermal Systems

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ISBN 13 :
Total Pages : pages
Book Rating : 4.:/5 (957 download)

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Book Synopsis Advancements in 3D Structural Analysis of Geothermal Systems by :

Download or read book Advancements in 3D Structural Analysis of Geothermal Systems written by and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Robust geothermal activity in the Great Basin, USA is a product of both anomalously high regional heat flow and active fault-controlled extension. Elevated permeability associated with some fault systems provides pathways for circulation of geothermal fluids. Constraining the local-scale 3D geometry of these structures and their roles as fluid flow conduits is crucial in order to mitigate both the costs and risks of geothermal exploration and to identify blind (no surface expression) geothermal resources. Ongoing studies have indicated that much of the robust geothermal activity in the Great Basin is associated with high density faulting at structurally complex fault intersection/interaction areas, such as accommodation/transfer zones between discrete fault systems, step-overs or relay ramps in fault systems, intersection zones between faults with different strikes or different senses of slip, and horse-tailing fault terminations. These conceptualized models are crucial for locating and characterizing geothermal systems in a regional context. At the local scale, however, pinpointing drilling targets and characterizing resource potential within known or probable geothermal areas requires precise 3D characterization of the system. Employing a variety of surface and subsurface data sets, we have conducted detailed 3D geologic analyses of two Great Basin geothermal systems. Using EarthVision (Dynamic Graphics Inc., Alameda, CA) we constructed 3D geologic models of both the actively producing Brady's geothermal system and a 'greenfield' geothermal prospect at Astor Pass, NV. These 3D models allow spatial comparison of disparate data sets in 3D and are the basis for quantitative structural analyses that can aid geothermal resource assessment and be used to pinpoint discrete drilling targets. The relatively abundant data set at Brady's, ~80 km NE of Reno, NV, includes 24 wells with lithologies interpreted from careful analysis of cuttings and core, a 1:24,000 scale detailed geologic map and cross-sections, 2D seismic reflection profiles and other geophysical data, and downhole temperature data. The 3D geologic model based on these data consists of 61 fault planes, 25 distinct stratigraphic units, and 2 intrusive bodies. Geothermal fluids are produced from a left step-over/relay ramp within the Brady's Fault Zone (BFZ). Under local stress conditions, fault segments that strike NNE-to-NE are most likely to slip and/or dilate, and therefore transmit geothermal fluids. The 3D model defines the locations of discrete fault intersections within the BFZ and indicates that the densest zones of structurally controlled fracture permeability are ~10-to-10s of meters in diameter and plunge ~55° NW-NNW beneath the heart of the BFZ step over. The locations of high intersection density, high fault slip and dilation tendency, high subsurface temperature, and lithologies known to support high fracture permeability are combined to produce 3D 'fairway' maps useful in both assessments of geothermal resource potential and for defining drilling targets. Astor Pass is located on the Pyramid Lake Paiute Reservation, ~80 km north of Reno, NV. It is a prospective 'greenfield' geothermal area, and thus subsurface data are relatively sparse. Available data include: two relatively deep wells (~1400 m) and one shallower well (~500 m) with lithologies interpreted from drill cuttings, several 2D seismic reflection profiles, a 1:24,000 scale geologic map and cross-section, a shallow temperature survey, and downhole temperature data. 3D modeling based on these data has defined 19 distinct fault planes and 16 stratigraphic units. Based on the stress field calculated from borehole breakouts, drilling induced tensile cracks and petal-centerline cracks in the two relatively deep wells, 3D slip and dilation tendency analysis indicates that northerly striking fault segments are most likely to slip and/or dilate, and therefore transmit geothermal fluids. Analysis of fault ...

Crustal Permeability

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Publisher : John Wiley & Sons
ISBN 13 : 111916656X
Total Pages : 557 pages
Book Rating : 4.1/5 (191 download)

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Book Synopsis Crustal Permeability by : Tom Gleeson

Download or read book Crustal Permeability written by Tom Gleeson and published by John Wiley & Sons. This book was released on 2016-11-30 with total page 557 pages. Available in PDF, EPUB and Kindle. Book excerpt: Permeability is the primary control on fluid flow in the Earth’s crust and is key to a surprisingly wide range of geological processes, because it controls the advection of heat and solutes and the generation of anomalous pore pressures. The practical importance of permeability – and the potential for large, dynamic changes in permeability – is highlighted by ongoing issues associated with hydraulic fracturing for hydrocarbon production (“fracking”), enhanced geothermal systems, and geologic carbon sequestration. Although there are thousands of research papers on crustal permeability, this is the first book-length treatment. This book bridges the historical dichotomy between the hydrogeologic perspective of permeability as a static material property and the perspective of other Earth scientists who have long recognized permeability as a dynamic parameter that changes in response to tectonism, fluid production, and geochemical reactions.

Geothermal Data of the United States

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ISBN 13 :
Total Pages : 106 pages
Book Rating : 4.3/5 ( download)

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Book Synopsis Geothermal Data of the United States by : Nelson Horatio Darton

Download or read book Geothermal Data of the United States written by Nelson Horatio Darton and published by . This book was released on 1920 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt:

A Case Study of the Newcastle Geothermal System, Iron County, Utah

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ISBN 13 :
Total Pages : 44 pages
Book Rating : 4.:/5 (31 download)

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Book Synopsis A Case Study of the Newcastle Geothermal System, Iron County, Utah by : Robert E. Blackett

Download or read book A Case Study of the Newcastle Geothermal System, Iron County, Utah written by Robert E. Blackett and published by . This book was released on 1992 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: Past exploration in low- and moderate-temperature systems of the Great Basin shows that the relatively small area associated with fluid upflow and elevated temperatures is often difficult to detect by drilling widely spaced temperature-gradient holes or by other methods. By studying the Newcastle geothermal system, we hoped to develop a basic understanding of the concealed hydrothemlal system as a tool for assessing other geothermal areas of the Great Basin. The emphasis of our work centered on determining (1) the distribution of subsurface heat and the movement of thermal fluid, (2) the location and geometry of bedrock structures that might control fluid movements, (3) the chemical character of the geothermal water, and (4) the geometry of the bedrock beneath the Escalante Desert. Field studies included: (1) drilling and monitoring temperatures in shallow themlal-gradient boreholes, (2) mapping geologic units and performing structural studies in the adjacent mountains, (3) conducting detailed gravity surveys, (4) conducting electrical resistivity and self-potential (SP) surveys, (5) collecting water samples for detennining major ions and light stable isotope analyses, and (6) mapping Quaternary units.