Deformation Modeling Over Geologic Time PDF Download
Are you looking for read ebook online? Search for your book and save it on your Kindle device, PC, phones or tablets. Download Deformation Modeling Over Geologic Time PDF full book. Access full book title Deformation Modeling Over Geologic Time by Laainam Chaipornkaew. Download full books in PDF and EPUB format.
Author: Laainam Chaipornkaew
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
Forces from small earthquakes, moving cars, or even footsteps during a short period can cause deformation of the earth's crust to varying degrees, but these actions do not cause large-scale permanent damage to the crust. In contrast, forces from geological processes over millions of years cause rocks to bend and break permanently. The work presented in this dissertation presents two geomechanical modeling techniques, finite element method, and machine learning, to improve how we model the second kind of deformation: large-scale deformation. Specifically, the proposed modeling techniques enhance our understanding of the evolution of pore pressure and stress (part one of the dissertation) and the kinematic efficiency of the strike-slip fault system (part two of the dissertation). In terms of the evolution of pore pressure, predictions based on basin and petroleum system modeling (BPSM) still have limitations, especially those models with underlying assumptions that exclude inelasticity and non-vertical deformation. Hence, we offer an alternative modeling approach by incorporating a fully-coupled hydromechanical simulator that includes inelasticity, enabling us to track the dynamic properties of rock over time. Regarding the strike-slip fault system, the current understanding of off-fault deformation behavior is limited because quantifying individual control (i.e., fault geometry, roughness, and connectivity) neglects the effects of the inter-relationship of these three controls on fault behaviors. Hence, we offer an alternative solution by harnessing a machine learning algorithm that can relate all relevant parameters in higher dimensions to estimate off-fault deformation. The first part of this dissertation explains how this work improves predictions of the evolutionary pore pressure and stress. It consists of two chapters and addresses the following research objectives: (1) integrating advanced geomechanical concepts into basin and petroleum system modeling by incorporating more realistic assumptions, e.g., inelastic constitutive relation and non-vertical stress; (2) constructing a model that captures evolving properties of shale rocks as a function of stress and pore pressure for different levels of model complexity, such as fracturing, geometry, and boundary conditions; and (3) investigating stress, pore pressure generation, and pore pressure dissipation in a tectonically complex region by using a nonlinear stress-induced upscaled permeability. The second part of this dissertation explains the improvement in predicting the kinematic efficiency of strike-slip fault systems. It consists of one chapter and addresses the following research objectives: (1) utilizing a comprehensive labeled dataset under various loading conditions of simulated strike-slip faults to build a predictive model of off-fault deformation; (2) searching for the most appropriate architecture, loss functions, and hyperparameters that maximize the performance of the convolutional neural network (CNN) model on an unseen fault dataset; and (3) testing the hypothesis that the trained CNN model can estimate off-fault deformation that is consistent with geologic observations.
Author: Peter James Lovely
Publisher: Stanford University
ISBN:
Category :
Languages : en
Pages : 265
Get Book Here
Book Description
A thorough understanding of the kinematic and mechanical evolution of fault-related structures is of great value, both academic (e.g. How do mountains form?) and practical (e.g. How are valuable hydrocarbons trapped in fault-related folds?). Precise knowledge of the present-day geometry is necessary to know where to drill for hydrocarbons. Understanding the evolution of a structure, including displacement fields, strain and stress history, may offer powerful insights to how and if hydrocarbons might have migrated, and the most efficient way to extract them. Small structures, including faults, fractures, pressure solution seams, and localized compaction, which may strongly influence subsurface fluid flow, may be predictable with a detailed mechanical understanding of a structure's evolution. The primary focus of this thesis is the integration of field observations, geospatial data including airborne LiDAR, and numerical modeling to investigate three dimensional deformational patterns associated with fault slip accumulated over geologic time scales. The work investigates contractional tectonics at Sheep Mountain anticline, Greybull, WY, and extensional tectonics at the Volcanic Tableland, Bishop, CA. A detailed geometric model is a necessary prerequisite for complete kinematic or mechanical analysis of any structure. High quality 3D seismic imaging data provides the means to characterize fold geometry for many subsurface industrial applications; however, such data is expensive, availability is limited, and data quality is often poor in regions of high topography where outcrop exposures are best. A new method for using high resolution topographic data, geologic field mapping and numerical interpolation is applied to model the 3D geometry of a reservoir-scale fold at Sheep Mountain anticline. The Volcanic Tableland is a classic field site for studies of fault slip scaling relationships and conceptual models for evolution of normal faults. Three dimensional elastic models are used to constrain subsurface fault geometry from detailed maps of fault scarps and topography, and to reconcile two potentially competing conceptual models for fault growth: by coalescence and by subsidiary faulting. The Tableland fault array likely initiated as a broad array of small faults, and as some have grown and coalesced, their strain shadows have inhibited the growth and initiation of nearby faults. The Volcanic Tableland also is used as a geologic example in a study of the capabilities and limitations of mechanics-based restoration, a relatively new approach to modeling in structural geology that provides distinct advantages over traditional kinematic methods, but that is significantly hampered by unphysical boundary conditions. The models do not accurately represent geological strain and stress distributions, as many have hoped. A new mechanics-based retrodeformational technique that is not subject to the same unphysical boundary conditions is suggested. However, the method, which is based on reversal of tectonic loads that may be optimized by paleostress analysis, restores only that topography which may be explained by an idealized elastic model. Elastic models are appealing for mechanical analysis of fault-related deformation because the linear nature of such models lends itself to retrodeformation and provides computationally efficient and stable numerical implementation for simulating slip distributions and associated deformation in complicated 3D fault systems. However, cumulative rock deformation is not elastic. Synthetic models are applied to investigate the implications of assuming elastic deformation and frictionless fault slip, as opposed to a more realistic elasto-plastic deformation with frictional fault slip. Results confirm that elastic models are limited in their ability to simulate geologic stress distributions, but that they may provide a reasonable, first-order approximation of strain tensor orientation and the distribution of relative strain perturbations, particularly distal from fault tips. The kinematics of elastic and elasto-plastic models diverge in the vicinity of fault tips. Results emphasize the importance of accurately and completely representing subsurface fault geometry in linear or nonlinear models.
Author: Laainam Chaipornkaew
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
Forces from small earthquakes, moving cars, or even footsteps during a short period can cause deformation of the earth's crust to varying degrees, but these actions do not cause large-scale permanent damage to the crust. In contrast, forces from geological processes over millions of years cause rocks to bend and break permanently. The work presented in this dissertation presents two geomechanical modeling techniques, finite element method, and machine learning, to improve how we model the second kind of deformation: large-scale deformation. Specifically, the proposed modeling techniques enhance our understanding of the evolution of pore pressure and stress (part one of the dissertation) and the kinematic efficiency of the strike-slip fault system (part two of the dissertation). In terms of the evolution of pore pressure, predictions based on basin and petroleum system modeling (BPSM) still have limitations, especially those models with underlying assumptions that exclude inelasticity and non-vertical deformation. Hence, we offer an alternative modeling approach by incorporating a fully-coupled hydromechanical simulator that includes inelasticity, enabling us to track the dynamic properties of rock over time. Regarding the strike-slip fault system, the current understanding of off-fault deformation behavior is limited because quantifying individual control (i.e., fault geometry, roughness, and connectivity) neglects the effects of the inter-relationship of these three controls on fault behaviors. Hence, we offer an alternative solution by harnessing a machine learning algorithm that can relate all relevant parameters in higher dimensions to estimate off-fault deformation. The first part of this dissertation explains how this work improves predictions of the evolutionary pore pressure and stress. It consists of two chapters and addresses the following research objectives: (1) integrating advanced geomechanical concepts into basin and petroleum system modeling by incorporating more realistic assumptions, e.g., inelastic constitutive relation and non-vertical stress; (2) constructing a model that captures evolving properties of shale rocks as a function of stress and pore pressure for different levels of model complexity, such as fracturing, geometry, and boundary conditions; and (3) investigating stress, pore pressure generation, and pore pressure dissipation in a tectonically complex region by using a nonlinear stress-induced upscaled permeability. The second part of this dissertation explains the improvement in predicting the kinematic efficiency of strike-slip fault systems. It consists of one chapter and addresses the following research objectives: (1) utilizing a comprehensive labeled dataset under various loading conditions of simulated strike-slip faults to build a predictive model of off-fault deformation; (2) searching for the most appropriate architecture, loss functions, and hyperparameters that maximize the performance of the convolutional neural network (CNN) model on an unseen fault dataset; and (3) testing the hypothesis that the trained CNN model can estimate off-fault deformation that is consistent with geologic observations.
Author: A. Nicolas
Publisher: Springer Science & Business Media
ISBN: 9400937431
Category : Science
Languages : en
Pages : 230
Get Book Here
Book Description
Physicists attempt to reduce natural phenomena to their essential dimensions by means of simplification and approximation and to account for them by defining natural laws. Paradoxically, whilst there is a critical need in geology to reduce the overwhelming field information to its essentials, it often re mains in an over-descriptive state. This prudent attitude of geologists is dictated by the nature of the subjects being consi dered, as it is often difficult to derive the significant parame ters from the raw data. It also follows from the way that geolo gical work is carried out. Geologists proceed, as in a police investigation, by trying to reconstruct past conditions and events from an analysis of the features preserved in rocks. In physics all knowledge is based on experiment but in the Earth Sciences experimental evidence is of very limited scope and is difficult to interpret. The geologist's cautious approach in accepting evidence gained by modelling and quantification is sometimes questionable when it is taken too far. It shuts out potentially fruitful lines of advance; for instance when refu sing order of magnitude calculations, it risks being drowned in anthropomorphic speculation. Happily nowadays, many more studies tend to separate and order the significant facts and are carried out with numerical constraints, which although they are approxi mate in nature, limit the range of hypotheses and thus give rise to new models.
Author: Peter James Lovely
Publisher:
ISBN:
Category :
Languages : en
Pages :
Get Book Here
Book Description
A thorough understanding of the kinematic and mechanical evolution of fault-related structures is of great value, both academic (e.g. How do mountains form?) and practical (e.g. How are valuable hydrocarbons trapped in fault-related folds?). Precise knowledge of the present-day geometry is necessary to know where to drill for hydrocarbons. Understanding the evolution of a structure, including displacement fields, strain and stress history, may offer powerful insights to how and if hydrocarbons might have migrated, and the most efficient way to extract them. Small structures, including faults, fractures, pressure solution seams, and localized compaction, which may strongly influence subsurface fluid flow, may be predictable with a detailed mechanical understanding of a structure's evolution. The primary focus of this thesis is the integration of field observations, geospatial data including airborne LiDAR, and numerical modeling to investigate three dimensional deformational patterns associated with fault slip accumulated over geologic time scales. The work investigates contractional tectonics at Sheep Mountain anticline, Greybull, WY, and extensional tectonics at the Volcanic Tableland, Bishop, CA. A detailed geometric model is a necessary prerequisite for complete kinematic or mechanical analysis of any structure. High quality 3D seismic imaging data provides the means to characterize fold geometry for many subsurface industrial applications; however, such data is expensive, availability is limited, and data quality is often poor in regions of high topography where outcrop exposures are best. A new method for using high resolution topographic data, geologic field mapping and numerical interpolation is applied to model the 3D geometry of a reservoir-scale fold at Sheep Mountain anticline. The Volcanic Tableland is a classic field site for studies of fault slip scaling relationships and conceptual models for evolution of normal faults. Three dimensional elastic models are used to constrain subsurface fault geometry from detailed maps of fault scarps and topography, and to reconcile two potentially competing conceptual models for fault growth: by coalescence and by subsidiary faulting. The Tableland fault array likely initiated as a broad array of small faults, and as some have grown and coalesced, their strain shadows have inhibited the growth and initiation of nearby faults. The Volcanic Tableland also is used as a geologic example in a study of the capabilities and limitations of mechanics-based restoration, a relatively new approach to modeling in structural geology that provides distinct advantages over traditional kinematic methods, but that is significantly hampered by unphysical boundary conditions. The models do not accurately represent geological strain and stress distributions, as many have hoped. A new mechanics-based retrodeformational technique that is not subject to the same unphysical boundary conditions is suggested. However, the method, which is based on reversal of tectonic loads that may be optimized by paleostress analysis, restores only that topography which may be explained by an idealized elastic model. Elastic models are appealing for mechanical analysis of fault-related deformation because the linear nature of such models lends itself to retrodeformation and provides computationally efficient and stable numerical implementation for simulating slip distributions and associated deformation in complicated 3D fault systems. However, cumulative rock deformation is not elastic. Synthetic models are applied to investigate the implications of assuming elastic deformation and frictionless fault slip, as opposed to a more realistic elasto-plastic deformation with frictional fault slip. Results confirm that elastic models are limited in their ability to simulate geologic stress distributions, but that they may provide a reasonable, first-order approximation of strain tensor orientation and the distribution of relative strain perturbations, particularly distal from fault tips. The kinematics of elastic and elasto-plastic models diverge in the vicinity of fault tips. Results emphasize the importance of accurately and completely representing subsurface fault geometry in linear or nonlinear models.
Author: Yüksel Altiner
Publisher: Springer Science & Business Media
ISBN: 3662039354
Category : Science
Languages : en
Pages : 109
Get Book Here
Book Description
Due to plate motions, tidal effects of the Moon and the Sun, atmosphe ric, hydrological, ocean loading and local geological processes, and due to the rotation of the Earth, all points on the Earth's crust are sub ject to deformation. Global plate motion models, based on the ocean floor spreading rates, transform fault azimuths, and earthquake slip vectors, describe average plate motions for a time period of the past few million years. Therefore, the investigation of present-day tectonic activities by global plate motion models in a small area with complex movements cannot supply satisfactory results. The contribution of space techniques [Very Long Baseline Interferome try (VLBI); Satellite Laser Ranging (SLR); Global Positioning System (GPS)] applied to the present-day deformations ofthe Earth's surface and plate tectonics has increased during the last 20 to 25 years. Today one is able to determine by these methods the relative motions in the em to sub-em-range between points far away from each other.
Author: L.A. Lliboutry
Publisher: Springer Science & Business Media
ISBN: 9400935633
Category : Science
Languages : en
Pages : 518
Get Book Here
Book Description
This book is written primarily for Earth scientists faced with problems in thermo mechanics such as the flow and evolution of ice-sheets, convection currents in the mantle, isostatic rebound, folding of strata or collapse of cavities in salt domes. Failure, faults, seismic waves and all processes involving inertial terms will not be dealt with. In general such scientists (graduate students beginning a Ph. D. for instance) have too small a background'in continuum mechanics and in numerical computation to model conveniently these problems, which are not elementary at all. Most of them are not linear, and therefore seldom dealt with in treatises. If the study of reality were clearly cut into two successive steps: first to make a physical model, setting up a well-posed problem in thermo-mechanics, and second to solve it, the obvious solution would be to find a specialist in computational mechanics who could spend enough time on a problem which, although maybe crucial for on-going fundamental research, has little practical interest in general, and cannot be considered properly as a noteworthy progress in Mechanics. But this is not the way Science develops. There is a continuous dialectic between the building up of a model and its mathematical treatment. The model should be simple enough to be tractable, but not oversimplified. Its sensitivity to the different components it is made of should be investigated, and more thought is needed when the results contradict hard facts.
Author: A. Asaoka
Publisher: Elsevier
ISBN: 9780080428383
Category : Science
Languages : en
Pages : 956
Get Book Here
Book Description
Progressive failure has been a classical problem in the field of geotechnical engineering and has attracted considerable attention in connection with slope stability and foundation problems. It is associated with strain localization or shear banding and is also related to damage in material structures. As knowledge of the progressive failure mechanism increases, it is now necessary to establish effective communications between researchers and engineers. The International Symposium on Deformation and Progressive Failure in Geomechanics provided an opportunity for discussing recent advances in this area. A total of 136 papers were contributed from 22 countries. As well as these, the symposium proceedings also contain 8 interim technical reports on the subject by the members of the Asian Technical Committee of the International Society for Soil Mechanics and Foundation Engineering and the Japanese Geotechnical Society National Committee on Progressive Failure in Geo-structures.
Author: John G. Ramsay
Publisher:
ISBN:
Category : Geology, Structural
Languages : en
Pages : 38
Get Book Here
Book Description
Author: Andrea Villa
Publisher: Ledizioni
ISBN: 8895994140
Category : Mathematics
Languages : en
Pages : 134
Get Book Here
Book Description
The main object of this thesis is to provide a comprehensive numerical tool forthe three-dimensional simulation of sedimentary basins [94]. Sedimentary basins, in particular salt basins, are the best places to find oil, natural gas and to store dangerous nuclear waste material. The low permeability of salt guarantees low water leakage which is the main concern for the safety of a nuclear waste storage. For this reason one of the best places for a nuclear waste depository is a salt mine. These two applications call for a thorough knowledge of the basin evolution on geological time scales. Until now sedimentary basin studies have been based mainly on geological interpretation: experienced specialists estimate the history of a basin on the basis of common knowledge. More often, they provide a list of possible scenarios. An appropriate numerical simulator can provide the right tool to choose, among these scenarios, the correct one or, at least, the most realistic.
Author: Detlef Wolf
Publisher: Springer Science & Business Media
ISBN: 3764384174
Category : Science
Languages : en
Pages : 245
Get Book Here
Book Description
Most of the papers in this book were presented at the workshop on "Deformation and Gravity Change: Indicators of Isostasy, Tectonics, Volcanism and Climate Change", which took place at the Casa de los Volcanes on Lanzarote, during March 1-4, 2005. Leading experts describe major developments in geodynamics, and record their views on internal and surface processes of the earth.
