Geomechanics to Solve Geological Structure Issues: Forward, Inverse and Restoration Modeling

Geomechanics to Solve Geological Structure Issues: Forward, Inverse and Restoration Modeling PDF Author: Frantz Maerten
Publisher:
ISBN: 9781976863608
Category :
Languages : en
Pages : 457

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Book Description
Different applications of linear elasticity in structural geology are presented in this thesis through the development of three types of numerical computer codes. The first one uses forward modeling to study displacement and perturbed stress fields around complexly faulted regions. We show that incorporating inequality constraints, such as static Coulomb friction, enables one to explain the angle of initiation of jogs in extensional relays. Adding heterogeneous material properties and optimizations, such as parallelization on multicore architectures and complexity reduction, admits more complex models. The second type deals with inverse modeling, also called parameter estimation. Linear slip inversion on faults with complex geometry, as well as paleo-stress inversion using a geomechanical approach, are developed. The last type of numerical computer code is dedicated to restoration of complexly folded and faulted structures. It is shown that this technique enables one to check balanced cross-sections, and also to retrieve fault chronology. Finally, we show that this code allows one to smooth noisy 3D interpreted faulted and folded horizons using geomechanics.

Geomechanics to Solve Geological Structure Issues: Forward, Inverse and Restoration Modeling

Geomechanics to Solve Geological Structure Issues: Forward, Inverse and Restoration Modeling PDF Author: Frantz Maerten
Publisher:
ISBN: 9781976863608
Category :
Languages : en
Pages : 457

Get Book Here

Book Description
Different applications of linear elasticity in structural geology are presented in this thesis through the development of three types of numerical computer codes. The first one uses forward modeling to study displacement and perturbed stress fields around complexly faulted regions. We show that incorporating inequality constraints, such as static Coulomb friction, enables one to explain the angle of initiation of jogs in extensional relays. Adding heterogeneous material properties and optimizations, such as parallelization on multicore architectures and complexity reduction, admits more complex models. The second type deals with inverse modeling, also called parameter estimation. Linear slip inversion on faults with complex geometry, as well as paleo-stress inversion using a geomechanical approach, are developed. The last type of numerical computer code is dedicated to restoration of complexly folded and faulted structures. It is shown that this technique enables one to check balanced cross-sections, and also to retrieve fault chronology. Finally, we show that this code allows one to smooth noisy 3D interpreted faulted and folded horizons using geomechanics.

Fault-related Deformation Over Geologic Time

Fault-related Deformation Over Geologic Time PDF Author: Peter James Lovely
Publisher: Stanford University
ISBN:
Category :
Languages : en
Pages : 265

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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.

Paleostress Inversion Techniques

Paleostress Inversion Techniques PDF Author: Christophe Pascal
Publisher: Elsevier
ISBN: 0128119470
Category : Science
Languages : en
Pages : 278

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Book Description
Paleostress Inversion Techniques: Methods and Applications for Tectonics is an ideal reference for both academic and industry researchers in the Earth Sciences. The book introduces the methodologies developed to reconstruct (paleo) stress tensors from geological data. The interest and potential outcomes of the methods are illustrated by practical examples and supplementary electronic material and an overview on future research directions. As paleostress inversion methods are particularly useful in tectonic analyses at regional and local scales and their outcomes are relevant when trying to predict the orientations of fracture sets and potential fluid flow paths and associated mineralizations, this book provides an ideal resource. Includes detailed explanations of methods, along with concrete applications of paleostress inversion techniques Clearly illustrates the outcomes, advantages and limitations of the techniques Serves as a practical guide for both academics and industry researchers interested in structural geology, geodynamics and tectonics

The Geology of Kuwait

The Geology of Kuwait PDF Author: Abd el-aziz Khairy Abd el-aal
Publisher: Springer Nature
ISBN: 3031167279
Category : Science
Languages : en
Pages : 250

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Book Description
This open access book contains a set of chapters covering all aspects of geosciences related to Kuwait and adjacent regions, including Iran, Saudi Arabia and the Arab Gulf states. It covers basic information about the geology including a wide range of geoscientific disciplines such as marine geology, structural geology, hydrogeology and geophysics related to the region. This book is aimed at researchers and students, as well as professionals in the field of hazard mitigation and petroleum exploration.

Using Stokes Flow Equations for the Geomechanical Restoration of Geological Structural Models

Using Stokes Flow Equations for the Geomechanical Restoration of Geological Structural Models PDF Author: Melchior Schuh-Senlis
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
In order to study the subsurface, one must first understand its deformation through time. As the available data coverage is not sufficient to determine these deformations precisely, geologists make hypotheses to link them depending on their knowledge. This allows them to create structural models, which can be seen as the sum of all the data and knowledge on a specific area. Structural restoration was developped to try and make a model go back in time. The advantages are dual: first, it allows the validation of the structural model by checking if the restored model has a reasonable geometry. Second, the history and retro-deformation of the rock layers can be studied from the path they take during the restoration process (which also allows checking the hypotheses that were made on the history of the area). In the context of faulted and folded sedimentary basins, mechanics have been incorporated in the restoration process to compute the deformation of the rock layers inside the models, but the time reversal is still driven mainly by geometric conditions. In the context of basins incorporating salt tectonics, creeping flow restoration was developped by considering the rocks as highly viscous fluids, but neglects faults and non-flat topography. The main contribution of this thesis is to provide an approach to add more physical conditions to the restoration of faulted sedimentary basins. This approach relies on mechanical simulations of the subsurface. The rock layers are treated as highly viscous fluids, and the restoration is driven by a negative time-step advection. The faults are considered as shear zones with an effective viscosity lower than the surrounding sediments. This methods allowed the restoration of several simplified models of the subsurface. The second contribution of this thesis is an assessment of the choice of the parameters for the restoration simulations. This assessment is based on the restoration of a laboratory analogue model. The boundary conditions are first studied, to determine how to provide an adequate choice of conditions that still allow the restoration of the model. The material properties and their influence are then looked upon, to determine the effective parameters that are closest to those of the rocks inside the model. These contributions offer a new perspective on how to add more physical conditions to the geomechanical restoration of structural models of the subsurface.

Characterization, Modeling, Monitoring, and Remediation of Fractured Rock

Characterization, Modeling, Monitoring, and Remediation of Fractured Rock PDF Author: National Academies of Sciences, Engineering, and Medicine
Publisher: National Academies Press
ISBN: 0309373727
Category : Science
Languages : en
Pages : 177

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Book Description
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.

Geomechanics and Geology

Geomechanics and Geology PDF Author: J.P. Turner
Publisher: Geological Society of London
ISBN: 1786203200
Category : Science
Languages : en
Pages : 297

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Book Description
Geomechanics investigates the origin, magnitude and deformational consequences of stresses in the crust. In recent years awareness of geomechanical processes has been heightened by societal debates on fracking, human-induced seismicity, natural geohazards and safety issues with respect to petroleum exploration drilling, carbon sequestration and radioactive waste disposal. This volume explores the common ground linking geomechanics with inter alia economic and petroleum geology, structural geology, petrophysics, seismology, geotechnics, reservoir engineering and production technology. Geomechanics is a rapidly developing field that brings together a broad range of subsurface professionals seeking to use their expertise to solve current challenges in applied and fundamental geoscience. A rich diversity of case studies herein showcase applications of geomechanics to hydrocarbon exploration and field development, natural and artificial geohazards, reservoir stimulation, contemporary tectonics and subsurface fluid flow. These papers provide a representative snapshot of the exciting state of geomechanics and establish it firmly as a flourishing subdiscipline of geology that merits broadest exposure across the academic and corporate geosciences.

Structural Geology

Structural Geology PDF Author: Haakon Fossen
Publisher: Cambridge University Press
ISBN: 1139488619
Category : Science
Languages : en
Pages : 481

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Book Description
Lavishly illustrated in color, this textbook takes an applied approach to introduce undergraduate students to the basic principles of structural geology. The book provides unique links to industry applications in the upper crust, including petroleum and groundwater geology, which highlight the importance of structural geology in exploration and exploitation of petroleum and water resources. Topics range from faults and fractures forming near the surface to shear zones and folds of the deep crust. Students are engaged through examples and parallels drawn from practical everyday situations, enabling them to connect theory with practice. Containing numerous end-of-chapter problems, e-learning modules, and with stunning field photos and illustrations, this book provides the ultimate learning experience for all students of structural geology.

Geo-frontiers 2011

Geo-frontiers 2011 PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description


The Material Point Method for Geotechnical Engineering

The Material Point Method for Geotechnical Engineering PDF Author: James Fern
Publisher: CRC Press
ISBN: 0429650663
Category : Technology & Engineering
Languages : en
Pages : 420

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Book Description
This practical guide provides the best introduction to large deformation material point method (MPM) simulations for geotechnical engineering. It provides the basic theory, discusses the different numerical features used in large deformation simulations, and presents a number of applications -- providing references, examples and guidance when using MPM for practical applications. MPM covers problems in static and dynamic situations within a common framework. It also opens new frontiers in geotechnical modelling and numerical analysis. It represents a powerful tool for exploring large deformation behaviours of soils, structures and fluids, and their interactions, such as internal and external erosion, and post-liquefaction analysis; for instance the post-failure liquid-like behaviours of landslides, penetration problems such as CPT and pile installation, and scouring problems related to underwater pipelines. In the recent years, MPM has developed enough for its practical use in industry, apart from the increasing interest in the academic world.