Author: J. Bee Bednar
Publisher: SIAM
ISBN: 9780898712735
Category : Science
Languages : en
Pages : 472
Book Description
This collection of papers on geophysical inversion contains research and survey articles on where the field has been and where it's going, and what is practical and what is not. Topics covered include seismic tomography, migration and inverse scattering.
Geophysical Inversion
Author: J. Bee Bednar
Publisher: SIAM
ISBN: 9780898712735
Category : Science
Languages : en
Pages : 472
Book Description
This collection of papers on geophysical inversion contains research and survey articles on where the field has been and where it's going, and what is practical and what is not. Topics covered include seismic tomography, migration and inverse scattering.
Publisher: SIAM
ISBN: 9780898712735
Category : Science
Languages : en
Pages : 472
Book Description
This collection of papers on geophysical inversion contains research and survey articles on where the field has been and where it's going, and what is practical and what is not. Topics covered include seismic tomography, migration and inverse scattering.
Electromagnetic Methods in Applied Geophysics
Author: Misac N. Nabighian
Publisher: SEG Books
ISBN: 1560800224
Category : Electromagnetic fields
Languages : en
Pages : 989
Book Description
As a slag heap, the result of strip mining, creeps closer to his house in the Ohio hills, fifteen-year-old M. C. is torn between trying to get his family away and fighting for the home they love.
Publisher: SEG Books
ISBN: 1560800224
Category : Electromagnetic fields
Languages : en
Pages : 989
Book Description
As a slag heap, the result of strip mining, creeps closer to his house in the Ohio hills, fifteen-year-old M. C. is torn between trying to get his family away and fighting for the home they love.
Geophysics Today
Author: Sergey Fomel
Publisher: SEG Books
ISBN: 156080226X
Category : Science
Languages : en
Pages : 543
Book Description
Presents a collection of papers which appear in the September-October 2010 Geophysics special section, written by recognised experts in various areas of exploration geophysics, plus an additional group of papers drawn from Geophysics which address areas beyond those invited articles. The result is a snapshot of the state-of-the-art in the field.
Publisher: SEG Books
ISBN: 156080226X
Category : Science
Languages : en
Pages : 543
Book Description
Presents a collection of papers which appear in the September-October 2010 Geophysics special section, written by recognised experts in various areas of exploration geophysics, plus an additional group of papers drawn from Geophysics which address areas beyond those invited articles. The result is a snapshot of the state-of-the-art in the field.
Exploration with Deep Transient Electromagnetics
Author: K. M. Strack
Publisher: Elsevier Science Limited
ISBN: 9780444503978
Category :
Languages : en
Pages : 373
Book Description
Paperback. This is a comprehensive description of deep transient electromagnetics which allows the geophysicist to learn about the technique from the beginning of instrument design to the final interpretation. It covers the application of deep transient electromagnetics to oil exploration, geothermal exploration and deep crustal studies. Case histories are used to explain the concepts shown. Problems are included at the end of each chapter. Also, demonstration software is enclosed. The book may be used as a textbook as well as for design and development of a field system. In particular it will be of interest to research and exploration geophysicists and students.
Publisher: Elsevier Science Limited
ISBN: 9780444503978
Category :
Languages : en
Pages : 373
Book Description
Paperback. This is a comprehensive description of deep transient electromagnetics which allows the geophysicist to learn about the technique from the beginning of instrument design to the final interpretation. It covers the application of deep transient electromagnetics to oil exploration, geothermal exploration and deep crustal studies. Case histories are used to explain the concepts shown. Problems are included at the end of each chapter. Also, demonstration software is enclosed. The book may be used as a textbook as well as for design and development of a field system. In particular it will be of interest to research and exploration geophysicists and students.
Advances in Geophysics
Author:
Publisher: Academic Press
ISBN: 0128124148
Category : Science
Languages : en
Pages : 106
Book Description
Advances in Geophysics, Volume 58, the latest in this critically acclaimed serialized review journal that has published for over 50 years, contains the latest information available in the field. Users will find valuable chapters highlighting the Novel use of geodynamics in plate tectonic reconstruction, and on Optimized experimental design in the context of seismic full waveform inversion and seismic imaging. Since 1952, each volume in this series has been eagerly awaited, frequently consulted, and praised by researchers and reviewers alike. Now in its 58th volume, it is truly an essential publication for researchers in all fields of geophysics. - Provides high-level reviews of the latest innovations in geophysics - Written by recognized experts in the field - Essential publication for researchers in all fields of geophysics
Publisher: Academic Press
ISBN: 0128124148
Category : Science
Languages : en
Pages : 106
Book Description
Advances in Geophysics, Volume 58, the latest in this critically acclaimed serialized review journal that has published for over 50 years, contains the latest information available in the field. Users will find valuable chapters highlighting the Novel use of geodynamics in plate tectonic reconstruction, and on Optimized experimental design in the context of seismic full waveform inversion and seismic imaging. Since 1952, each volume in this series has been eagerly awaited, frequently consulted, and praised by researchers and reviewers alike. Now in its 58th volume, it is truly an essential publication for researchers in all fields of geophysics. - Provides high-level reviews of the latest innovations in geophysics - Written by recognized experts in the field - Essential publication for researchers in all fields of geophysics
Three-dimensional Finite-element Time-domain Modeling of the Marine Controlled-source Electromagnetic Method
Author: Evan Schankee Um
Publisher: Stanford University
ISBN:
Category :
Languages : en
Pages : 207
Book Description
The survey design and data interpretation of the marine controlled-source electromagnetic (CSEM) method require modeling of complex and often subtle offshore geology with accuracy and efficiency. In this dissertation, I develop two efficient finite-element time-domain (FETD) algorithms for the simulation of three-dimensional (3D) electromagnetic (EM) diffusion phenomena. The two FETD algorithms are used to investigate the time-domain CSEM (TDCSEM) method in realistic shallow offshore environments and the effects of seafloor topography and seabed anisotropy on the TDCSEM method. The first FETD algorithm directly solves electric fields by applying the Galerkin method to the electric-field diffusion equation. The time derivatives of the magnetic fields are interpolated at receiver positions via Faraday's law only when the EM fields are output. Therefore, this approach minimizes the total number of unknowns to solve. To ensure both numerical stability and an efficient time-step, the system of FETD equations is discretized using an implicit backward Euler scheme. A sparse direct solver is employed to solve the system of equations. In the implementation of the FETD algorithm, I effectively mitigate the computational cost of solving the system of equations at every time step by reusing previous factorization results. Since the high frequency contents of the transient electric fields attenuate more rapidly in time, the transient electric fields diffuse increasingly slowly over time. Therefore, the FETD algorithm adaptively doubles a time-step size, speeding up simulations. Although the first FETD algorithm has the minimum number of unknowns, it still requires a large amount of memory because of its use of a direct solver. To mitigate this problem, the second FETD algorithm is derived from a vector-and-scalar potential equation that can be solved with an iterative method. The time derivative of the Lorenz gauge condition is used to split the ungauged vector-and-scalar potential equation into a diffusion equation for the vector potential and Poisson's equation for the scalar potential. The diffusion equation for the time derivative of the magnetic vector potentials is the primary equation that is solved at every time step. Poisson's equation is considered a secondary equation and is evaluated only at the time steps where the electric fields are output. A major advantage of this formulation is that the system of equations resulting from the diffusion equation not only has the minimum number of unknowns but also can be solved stably with an iterative solver in the static limit. The developed FETD algorithms are used to simulate the TDCSEM method in shallow offshore models that are derived from SEG salt model. In the offshore models, horizontal and vertical electric-dipole-source configurations are investigated and compared with each other. FETD simulation and visualization play important roles in analyzing the EM diffusion of the TDCSEM configurations. The partially-'guided' diffusion of transient electric fields through a thin reservoir is identified on the cross-section of the seabed models. The modeling studies show that the TDCSEM method effectively senses the localized reservoir close to the large-scale salt structure in the shallow offshore environment. Since the reservoir is close to the salt, the non-linear interaction of the electric fields between the reservoir and the salt is observed. Regardless of whether a horizontal or vertical electric-dipole source is used in the shallow offshore models, inline vertical electric fields at intermediate-to-long offsets are approximately an order of magnitude smaller than horizontal counterparts due to the effect of the air-seawater interface. Consequently, the vertical electric-field measurements become vulnerable to the receiver tilt that results from the irregular seafloor topography. The 3D modeling studies also illustrate that the short-offset VED-Ex configuration is very sensitive to a subtle change of the seafloor topography around the VED source. Therefore, the VED-Ex configuration is vulnerable to measurements and modeling errors at short offsets. In contrast, the VED-Ez configuration is relatively robust to these problems and is considered a practical short-offset configuration. It is demonstrated that the short-offset configuration can be used to estimate the lateral extent and depth of the reservoir. Vertical anisotropy in background also significantly affects the pattern in electric field diffusion by elongating and strengthening the electric field in the horizontal direction. As the degree of vertical anisotropy increases, the vertical resistivity contrast across the reservoir interface decreases. As a result, the week reservoir response is increasingly masked by the elongated and strengthened background response. Consequently, the TDCSEM method loses its sensitivity to the reservoir.
Publisher: Stanford University
ISBN:
Category :
Languages : en
Pages : 207
Book Description
The survey design and data interpretation of the marine controlled-source electromagnetic (CSEM) method require modeling of complex and often subtle offshore geology with accuracy and efficiency. In this dissertation, I develop two efficient finite-element time-domain (FETD) algorithms for the simulation of three-dimensional (3D) electromagnetic (EM) diffusion phenomena. The two FETD algorithms are used to investigate the time-domain CSEM (TDCSEM) method in realistic shallow offshore environments and the effects of seafloor topography and seabed anisotropy on the TDCSEM method. The first FETD algorithm directly solves electric fields by applying the Galerkin method to the electric-field diffusion equation. The time derivatives of the magnetic fields are interpolated at receiver positions via Faraday's law only when the EM fields are output. Therefore, this approach minimizes the total number of unknowns to solve. To ensure both numerical stability and an efficient time-step, the system of FETD equations is discretized using an implicit backward Euler scheme. A sparse direct solver is employed to solve the system of equations. In the implementation of the FETD algorithm, I effectively mitigate the computational cost of solving the system of equations at every time step by reusing previous factorization results. Since the high frequency contents of the transient electric fields attenuate more rapidly in time, the transient electric fields diffuse increasingly slowly over time. Therefore, the FETD algorithm adaptively doubles a time-step size, speeding up simulations. Although the first FETD algorithm has the minimum number of unknowns, it still requires a large amount of memory because of its use of a direct solver. To mitigate this problem, the second FETD algorithm is derived from a vector-and-scalar potential equation that can be solved with an iterative method. The time derivative of the Lorenz gauge condition is used to split the ungauged vector-and-scalar potential equation into a diffusion equation for the vector potential and Poisson's equation for the scalar potential. The diffusion equation for the time derivative of the magnetic vector potentials is the primary equation that is solved at every time step. Poisson's equation is considered a secondary equation and is evaluated only at the time steps where the electric fields are output. A major advantage of this formulation is that the system of equations resulting from the diffusion equation not only has the minimum number of unknowns but also can be solved stably with an iterative solver in the static limit. The developed FETD algorithms are used to simulate the TDCSEM method in shallow offshore models that are derived from SEG salt model. In the offshore models, horizontal and vertical electric-dipole-source configurations are investigated and compared with each other. FETD simulation and visualization play important roles in analyzing the EM diffusion of the TDCSEM configurations. The partially-'guided' diffusion of transient electric fields through a thin reservoir is identified on the cross-section of the seabed models. The modeling studies show that the TDCSEM method effectively senses the localized reservoir close to the large-scale salt structure in the shallow offshore environment. Since the reservoir is close to the salt, the non-linear interaction of the electric fields between the reservoir and the salt is observed. Regardless of whether a horizontal or vertical electric-dipole source is used in the shallow offshore models, inline vertical electric fields at intermediate-to-long offsets are approximately an order of magnitude smaller than horizontal counterparts due to the effect of the air-seawater interface. Consequently, the vertical electric-field measurements become vulnerable to the receiver tilt that results from the irregular seafloor topography. The 3D modeling studies also illustrate that the short-offset VED-Ex configuration is very sensitive to a subtle change of the seafloor topography around the VED source. Therefore, the VED-Ex configuration is vulnerable to measurements and modeling errors at short offsets. In contrast, the VED-Ez configuration is relatively robust to these problems and is considered a practical short-offset configuration. It is demonstrated that the short-offset configuration can be used to estimate the lateral extent and depth of the reservoir. Vertical anisotropy in background also significantly affects the pattern in electric field diffusion by elongating and strengthening the electric field in the horizontal direction. As the degree of vertical anisotropy increases, the vertical resistivity contrast across the reservoir interface decreases. As a result, the week reservoir response is increasingly masked by the elongated and strengthened background response. Consequently, the TDCSEM method loses its sensitivity to the reservoir.
Three-dimensional Electromagnetics
Author: Michael L. Oristaglio
Publisher: SEG Books
ISBN: 1560800798
Category : Science
Languages : en
Pages : 720
Book Description
This book covers major techniques used to compute, analyze, visualize, and understand 3D electromagnetic fields in every major application of electrical geophysics. The 44 papers, written especially for this volume, are divided between techniques of 3D modeling and inversion (21 papers) and applications (23 papers). The latter include exploration for minerals and hydrocarbons, regional crustal studies, and environmental surveys. These contributions represent the work of 95 authors from 56 institutions in 13 countries.
Publisher: SEG Books
ISBN: 1560800798
Category : Science
Languages : en
Pages : 720
Book Description
This book covers major techniques used to compute, analyze, visualize, and understand 3D electromagnetic fields in every major application of electrical geophysics. The 44 papers, written especially for this volume, are divided between techniques of 3D modeling and inversion (21 papers) and applications (23 papers). The latter include exploration for minerals and hydrocarbons, regional crustal studies, and environmental surveys. These contributions represent the work of 95 authors from 56 institutions in 13 countries.
Electromagnetic Seabed Logging
Author: Stéphane Sainson
Publisher: Springer
ISBN: 3319453556
Category : Science
Languages : en
Pages : 549
Book Description
Seabed logging (SBL) gathers the electromagnetic methods of marine subsoil exploration and more specifically those dedicated to the exploration of oil and gas at sea. Appeared in 2000, these techniques, with more than 500 industrial jobs, present after 15 years of commercial success a discovery record rate of nearly 90 % and seem now to turn the world in the offshore exploration field. Proposing a serious index of the presence of hydrocarbons , electromagnetic SBL coupled with seismic reflection survey is probably the first reliable method for direct detection of hydrocarbons. Complementing the structural concepts of oil exploration used since the 1920s, the SBL now radically modifies the approach and the philosophies of exploration especially those then including drilling and well logging activities. Electromagnetic Seabed Logging: a new tool for oil and gas prospecting, which original publication in French was in 2012, presents these methods, its principles, advantages, limitations, instruments, modeling and applications. It is also designed to be a tool for a reflection on the use of electromagnetic energy for the exploration in a conductive medium as sea water thus setting the theoretical and practical limits of these investigations for future developments. This book is intended of course for the geophysicists and the petroleum geologists, but also for the earth scientists, the reservoir engineers and the log analysts
Publisher: Springer
ISBN: 3319453556
Category : Science
Languages : en
Pages : 549
Book Description
Seabed logging (SBL) gathers the electromagnetic methods of marine subsoil exploration and more specifically those dedicated to the exploration of oil and gas at sea. Appeared in 2000, these techniques, with more than 500 industrial jobs, present after 15 years of commercial success a discovery record rate of nearly 90 % and seem now to turn the world in the offshore exploration field. Proposing a serious index of the presence of hydrocarbons , electromagnetic SBL coupled with seismic reflection survey is probably the first reliable method for direct detection of hydrocarbons. Complementing the structural concepts of oil exploration used since the 1920s, the SBL now radically modifies the approach and the philosophies of exploration especially those then including drilling and well logging activities. Electromagnetic Seabed Logging: a new tool for oil and gas prospecting, which original publication in French was in 2012, presents these methods, its principles, advantages, limitations, instruments, modeling and applications. It is also designed to be a tool for a reflection on the use of electromagnetic energy for the exploration in a conductive medium as sea water thus setting the theoretical and practical limits of these investigations for future developments. This book is intended of course for the geophysicists and the petroleum geologists, but also for the earth scientists, the reservoir engineers and the log analysts
Advances in Modeling and Interpretation in Near Surface Geophysics
Author: Arkoprovo Biswas
Publisher: Springer Nature
ISBN: 3030289095
Category : Science
Languages : en
Pages : 427
Book Description
This book deals primarily with the aspects of advances in near surface geophysical data modeling, different interpretation techniques, new ideas and an integrated study to delineate the subsurface structures. It also involves the practical application of different geophysical methods to delineate the subsurface structures associated with mineral, groundwater exploration, subsurface contamination, hot springs, coal fire etc. This book is specifically aimed with the state-of-art information regarding research advances and new developments in these areas of study, coupled to extensive modeling and field investigations obtained from around the world. It is extremely enlightening for the research workers, scientists, faculty members and students, in Applied Geophysics, Near Surface Geophysics, Potential Field, Electrical and Electromagnetic Methods, Mathematical Modeling Techniques in Earth Sciences, as well as Environmental Geophysics.
Publisher: Springer Nature
ISBN: 3030289095
Category : Science
Languages : en
Pages : 427
Book Description
This book deals primarily with the aspects of advances in near surface geophysical data modeling, different interpretation techniques, new ideas and an integrated study to delineate the subsurface structures. It also involves the practical application of different geophysical methods to delineate the subsurface structures associated with mineral, groundwater exploration, subsurface contamination, hot springs, coal fire etc. This book is specifically aimed with the state-of-art information regarding research advances and new developments in these areas of study, coupled to extensive modeling and field investigations obtained from around the world. It is extremely enlightening for the research workers, scientists, faculty members and students, in Applied Geophysics, Near Surface Geophysics, Potential Field, Electrical and Electromagnetic Methods, Mathematical Modeling Techniques in Earth Sciences, as well as Environmental Geophysics.
The Magnetotelluric Method
Author: Alan D. Chave
Publisher: Cambridge University Press
ISBN: 1107376971
Category : Science
Languages : en
Pages : 571
Book Description
The magnetotelluric method is a technique for imaging the electrical conductivity and structure of the Earth, from the near surface down to the 410 km transition zone and beyond. This book forms the first comprehensive overview of magnetotellurics, from the salient physics and its mathematical representation to practical implementation in the field, data processing, modeling and geological interpretation. Electromagnetic induction in 1-D, 2-D and 3-D media is explored, building from first principles, and with thorough coverage of the practical techniques of time series processing, distortion, numerical modeling and inversion. The fundamental principles are illustrated with a series of case histories describing geological applications. Technical issues, instrumentation and field practices are described for both land and marine surveys. This book provides a rigorous introduction to magnetotellurics for academic researchers and advanced students, and will be of interest to industrial practitioners and geoscientists wanting to incorporate rock conductivity into their interpretations.
Publisher: Cambridge University Press
ISBN: 1107376971
Category : Science
Languages : en
Pages : 571
Book Description
The magnetotelluric method is a technique for imaging the electrical conductivity and structure of the Earth, from the near surface down to the 410 km transition zone and beyond. This book forms the first comprehensive overview of magnetotellurics, from the salient physics and its mathematical representation to practical implementation in the field, data processing, modeling and geological interpretation. Electromagnetic induction in 1-D, 2-D and 3-D media is explored, building from first principles, and with thorough coverage of the practical techniques of time series processing, distortion, numerical modeling and inversion. The fundamental principles are illustrated with a series of case histories describing geological applications. Technical issues, instrumentation and field practices are described for both land and marine surveys. This book provides a rigorous introduction to magnetotellurics for academic researchers and advanced students, and will be of interest to industrial practitioners and geoscientists wanting to incorporate rock conductivity into their interpretations.