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.
Seismoelectric coupling and its current and potential future applications The seismoelectric method—the naturally-occurring coupling of seismic waves to electromagnetic fields—can provide insight into important properties of porous media. With a variety of potential environmental and engineering uses, as well as larger scale applications such as earthquake detection and oil and gas exploration, it offers a number of advantages over conventional geoEdit HTML Sourcephysical methods. Seismoelectric Exploration: Theory, Experiments, and Applications explores the coupling between poroelastic and electromagnetic disturbances, discussing laboratory experiments, numerical modeling techniques, recent theoretical developments, and field studies. Volume highlights include: Physics of the seismoelectric effect at the microscale Governing equations describing coupled seismo-electromagnetic fields Examples of successful seismoelectric field experiments in different geological settings Current and potential applications of seismoelectric coupling Noise removal techniques for seismoelectric field measurements The American Geophysical Union promotes discovery in Earth and space science for the benefit of humanity. Its publications disseminate scientific knowledge and provide resources for researchers, students, and professionals.
L’électrographie de fond de mer (EFM) regroupe les méthodes électromagnétiques d’exploration du sous-sol marin et plus spécifiquement celles dédiées à la prospection des hydrocarbures en mer. Apparues commercialement en 2000, ces techniques, avec plus de 500 opérations industrielles, présentent après 10 ans de succès commerciaux un taux record de découverte de près de 90 %, et semblent aujourd’hui bouleverser la donne en matière de recherche pétrolière offshore. En proposant un indice de présence d’hydrocarbures sérieux, l’EFM couplée à la sismique réflexion est probablement la première méthode fiable de détection directe des hydrocarbures. Complétant les concepts structuralistes de la prospection indirecte en vigueur depuis les années 1920, l’EFM modifie aujourd’hui radicalement l’approche et les philosophies d’exploration, en particulier celles incluant en aval les activités de forages et de diagraphies de fond de trou. S’appuyant sur les lois de l’électromagnétisme (équations de Maxwell), Électrographies de fond de mer décrit et analyse en détail les principes physiques, les méthodes, les techniques et les technologies mis en œuvre ou en voie de l’être. De plus, une note historique montrant l’évolution des idées, des concepts et des matériels depuis les années 1930, dates des premières tentatives, complète chaque chapitre. Synthèse unique, cet ouvrage abondamment illustré constitue un véritable outil de réflexion sur l’utilisation en prospection de l’énergie électromagnétique en milieu conducteur (eau de mer) fixant ainsi les limites théoriques et pratiques de ces investigations pour les développements à venir. Destiné aux géophysiciens et géologues du pétrole, il sera également utile aux physiciens du globe, aux ingénieurs réservoir, aux diagraphistes, aux log analysts, ainsi qu’à tous les étudiants en géosciences.
At the heart of this book is the generalized theoretical approach that is applied to investigate the geoelectrical structure of the Earth’s mantle. It also analyzes the results of regional and global induction sounding of the Earth’s mantle and compares them with the results obtained by other geophysical methods. The generalized theoretical approach employs the Induction Law as a basis for identifying extended relations between magnetic field components, including their plane divergence, impedances and spatial derivatives. The estimations of impedance values and spatial derivatives are performed using the theory of stochastic processes. The book also considers the external sources of magnetic fields used for sounding the Earths mantle from the modern theory perspective, as well as the problem of coincidence of magneto-variation and magnetotelluric methods. Further, it discusses secular variations in the Earth’s resistance caused by non-induction sources, factors that are correlated with the number of earthquakes in the region and shifted in time with global indexes. It is a valuable resource for scientists applying deep induction soundings or interested in the structures of and processes in the Earth’s interior.
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
Electromagnetic Sounding of the Earth's Interior 2nd edition provides a comprehensive up-to-date collection of contributions, covering methodological, computational and practical aspects of Electromagnetic sounding of the Earth by different techniques at global, regional and local scales. Moreover, it contains new developments such as the concept of self-consistent tasks of geophysics and , 3-D interpretation of the TEM sounding which, so far, have not all been covered by one book. Electromagnetic Sounding of the Earth's Interior 2nd edition consists of three parts: I- EM sounding methods, II- Forward modelling and inversion techniques, and III - Data processing, analysis, modelling and interpretation. The new edition includes brand new chapters on Pulse and frequency electromagnetic sounding for hydrocarbon offshore exploration. Additionally all other chapters have been extensively updated to include new developments. - Presents recently developed methodological findings of the earth's study, including seismoelectrical and renewed magnetovariational approaches - Provides methodological guidelines for Electromagnetic data interpretation in various geological environments - Contains a balanced set of lectures covering all aspects of Electromagnetic sounding at global, regional and local levels along with case studies, highlighting the practical importance of electromagnetic data - Updates current findings in the field, in particular MT, magnetovariational and seismo-electrical methods and the practice of 3D interpretations
A rigorous introduction to magnetotelluric imaging of Earth's electrical conductivity and structure, for researchers, advanced students and industrial practitioners.
On 6-7 April 1979 a two-day workshop on geomagnetism was held at the Air Force Geophysics Laboratory (AFGL). Proceedings of the workshop presented here include: reports on tutorial sessions concerning magnetospheric and geomagnetic pulsations, summaries of contributed papers, descriptions of active magnetometer networks, conclusions of workshop-discussion groups. Special emphasis is given to the use and future potential of the AFGL midlatitude magnetometer chain.
