nach oben

Erschienen in:

2017 | OriginalPaper | Buchkapitel

3. Metrology and Environment

verfasst von : Stéphane Sainson

Erschienen in: Electromagnetic Seabed Logging

Verlag: Springer International Publishing

Einloggen

Aktivieren Sie unsere intelligente Suche, um passende Fachinhalte oder Patente zu finden.

search-config

KI-gestützte Suche

Aus

Abstract

This chapter describes the physical environment where measurements will be made. It then presents the electromagnetic properties of the concerned media (electrical conductivity, magnetic permeability and dielectric permittivity) depending on the characteristics of seawater and subsoil rocks (facies, lithology). It then discusses the frequency and temporal aspects of the detection method depending on the propagation media and the background noise in the deep sea (several $ \mathrm{p}\mathrm{V}/\mathrm{m}/\sqrt{\mathrm{Hz}} $). It defines in substance the skin effect, the energy attenuation, the investigation depth, the magnitude of the amplitudes of the fields accessible to measurement (about 1 $ \upmu \mathrm{V}/\mathrm{m}/\sqrt{\mathrm{Hz}} $ or, if normalized, about 10⁻¹² V/A.m²), the signal-to-noise ratio and the modes and propagation/diffusion conditions in the presence or absence of oil. Then it proposes data acquisition systems to establish the intrinsic characteristics of the measuring instruments and especially the power of the transmitters and the receptor sensitivity. This chapter ends with a description of optimal conditions of detection and favorable field procedures.

Sie haben noch keine Lizenz? Dann Informieren Sie sich jetzt über unsere Produkte:

Springer Professional "Wirtschaft+Technik"

Online-Abonnement

Mit Springer Professional "Wirtschaft+Technik" erhalten Sie Zugriff auf:

über 102.000 Bücher
über 537 Zeitschriften

aus folgenden Fachgebieten:

Automobil + Motoren
Bauwesen + Immobilien
Business IT + Informatik
Elektrotechnik + Elektronik
Energie + Nachhaltigkeit
Finance + Banking
Management + Führung
Marketing + Vertrieb
Maschinenbau + Werkstoffe
Versicherung + Risiko

Jetzt Wissensvorsprung sichern!

Jetzt informieren

Springer Professional "Technik"

Online-Abonnement

Mit Springer Professional "Technik" erhalten Sie Zugriff auf:

über 67.000 Bücher
über 390 Zeitschriften

aus folgenden Fachgebieten:

Automobil + Motoren
Bauwesen + Immobilien
Business IT + Informatik
Elektrotechnik + Elektronik
Energie + Nachhaltigkeit
Maschinenbau + Werkstoffe

Jetzt Wissensvorsprung sichern!

Jetzt informieren

Vorheriges Kapitel Principles and Methods

Nächstes Kapitel Instrumentation and Equipment

An increase in accuracy (see note below) can only be effective if the quantity to be measured is well defined at each point where the determination is made.

Minerals such as arsenides and sulphides have the two conductivity types, which do not make them good conductors.

The conductivity of minerals is more complex to understand.

Porous and permeable rocks have resistivities that may very significantly differ depending on the nature of the fluids contained therein. For example, sands containing oil or gas will have a much larger resistivity than those containing salt water. Moreover, if we consider that the resistivity is part of a more macroscopic concept (volume including the notions of stratum, bench, layer, etc.), the resistivity at a given temperature then depends on three basic factors, which are the lithologic character, the amount of present pore water and the mineralization of the latter.

The hydrostatic pressure is given by the formula: p = hρg where h is the height of water, ρ is the volumic mass of water (1028 kg/m³) and g is the value of the acceleration of gravity (9.81 m/s²). Depending on the case, it is expressed in bars, Pa or psi. Whenever it sinks 10 m, the pressure increases a bar. At 4000 m deep, the pressure is equal to 40 MPa (5800 psi).

However, it is possible to achieve consistent results through the application of Knudsen's dosage method (Knudsen 1901; Thomsen and Menache 1954).

The first temperature measurements at sea and in deep water date from the end of the eighteenth century (1785–1788 campaigns of the Venus).

The physicists Gray and Wheeler in 1720 were the first to measure the electrical conductivity of some rocks (Seguin 1971), followed in the nineteenth century by some others (Becquerel 1834, 1847; Bruck 1841).

This factor is to link the shape of the pores and their degree of connection. For round grains (sand), m is equal to 1.4, while for the tabular grains (clay), the m value increases to 1.9. For fractured rocks, m can rise to 2.5.

For oil and gas, the n values respectively are 2.08 and 1.162.

They are also used in industry as an electrical insulator (e.g., in transformers).

The deposit water contains salts and ions in solution (Cl⁻, Na⁺, Ca²⁺, Mg²⁺, K⁺), dispersed colloids and dissolved gases (N₂, CO₂ and CH₄). The main characteristics of the deposit water come from their primary and secondary origin (Robert 1959).

The Archie and Humble formulas, used for the exploitation of electric logs, admit higher values for exponents m and n (close to 2). This leads us to assign to the reservoirs resistivity values much lower than those observed on electrical logs (Serra 2004). The anisotropy of the geological layers is one of the reasons partly invoked to explain these differences. The factors m and n are described in detail in the technical literature, and more particularly the one concerned with logs.

Research led in the context of underwater detection and published as monographs by the US Navy Underwater Sound Laboratory also relating the EM studies (Bannister 1980).

Distance at which the amplitude of the wave is equal to 36.8 % of the amplitude E_o, ie $ {E}_{\mathrm{o}}={\mathrm{e}}^{-\frac{k}{\sqrt{2}}\ \updelta}={E}_{\mathrm{o}}/ e $ being the base of natural logarithms and corresponding to ln(e) = or to exp(1) = e. This number may be defined as: $ e=\mathrm{l}\underset{n\to\ \infty }{\mathrm{im}\ {e}_n}=2,718281.... $ with e _n = 1/0! + 1/1! + 1/2! + .... + 1/n!

In various nonmagnetic sedimentary grounds, μ_r varies from 1 to 1.00001, and can be then considered as a constant (≈1).

Ampere/Maxwell’s law implicitly involves a duality between two types of current. At low frequencies, in the conductors, conduction currents are predominant, whereas in the higher frequencies (σ/ωε ≪ 1), i.e., those that are above the light spectra, the movement currents predominate. In DC, investigation depth and penetration depth are then equivalent (no skin effect) and among other things depend on the geometry of the acquisition device (the distance between the electrodes of the injection device particularly). These concepts were defined for the first time in 1938 (Evjen 1938) then supplemented by many authors (Guérin 2007).

Unique field independent of the distance.

The electric field is distributed according to the same law.

See Chap. 5.

See Chap. 4.

Phenomenon not yet exploited. In seismic exploration, in the 1960s, a similar technique was proposed to directly assess the thicknesses of the sedimentary layers.

See also Kraichman (1976).

Theory of images modified in a infinite conducting half space.

Polar coordinates (r, θ) reported in Cartesian coordinates.

For dialing (1, 2, 3, 4, 5) see diagram (see Fig. 3.19a ).

An overview of this process is presented in the thesis of L. Loseth (2007).

We call Green’s function, denoted G, the elementary solution of a linear differential equation or a partial derivative equation with constant coefficients. In electromagnetism, the solution is obtained using a single source (pulse or Dirac delta or δ). The general solution corresponding to the actual source is then equivalent to the superposition of impulse responses, that is to say, corresponding to the Green functions. These functions may take varied forms as, for example, analytic functions when the solution of the homogeneous differential equation is known, or an infinite series of orthogonal functions then satisfying the boundary conditions when the solution of the equation is unknown.

Vector that indicates the direction and the sense of propagation of an electromagnetic wave. The modulus of the Poynting vector (P ≈ E∧H) corresponds to a flux, power per area unit (Skilling 1942).

The potential vector is a mathematical tool that allows us, by introducing additional functions, to simplify the calculation procedures for the evaluation of magnetic and electric fields. For example, the fields are calculated from the potentials (specified sources), solutions of the Helmholtz equation.

The Lorenz gauge decouples differential equations on the vector and scalar potential and then gives rise to a general solution using Green’s functions.

Other authors have developed solutions in an infinite medium (Chave and Cox 1982).

When the study of one of its parameters by either method produces the same result, the function is called ergodic.

Generally these latter correspond to epiphenomena restricted in time.

In marine exploration this could be the case above basaltic horizons or salt domes, diapirs, gas hydrates, etc. In the 1970s, very low frequency devices were proposed (Duroux 1974).

See Chap. 4, devoted to instrumentation.

Not to be confused with electrometer calibration, which is done on the surface ship before immersion (cf. Sect. 6.7).

Accuracy is evaluating the absence of errors e (e = measured value – actual value). When the latter are present, the equation becomes Q _e = f (P) + e, e = Q – Q _e

There are two kinds of errors: time-independent (static) errors and time-dependent (dynamic) errors, which respectively are in the form e _S = g(Q), e = g(Q, t)

The coherent noise is, for example, a case of dynamic error. However, there are random variations related to the environment that can only be treated by statistical methods. The arithmetic average of a finite number N of measurements is then:

$$ \overline{Q}=\frac{1}{N}{\displaystyle \sum_{i = 1}^N{Q}_i} $$

The errors affecting the accuracy mainly come from the sensors, the processing and the location of the instruments (T/R). Errors can also be classified into systematic, random or accidental errors and mathematically defined. More simply, an absolute error is defined as the difference between the measurement and the true value, and a relative error as the ratio of the absolute error to the true or measured value.

The anodes only debit when there is a loss of electrical insulation; steel is then in contact with seawater (Sainson 2007).

Campaign led by the LETI (Commissariat for Atomic Energy) in the Mediterranean in July 1991.

Additional measurements simultaneously realized on land.

The means of propulsion of the ship, the shaft and propeller especially, produce (by their more or less regular rotation in sea water) alternating currents that are variable on the fundamental frequencies and their harmonics (hash of the lines of force static → modulation of the currents → BF variable fields).

After determining the characteristic frequencies (captures and measures), electromagnetic signatures are obtained by modeling (solving Maxwell’s equations).

Effect demonstrated for the first time in 1879 by British scientists of the Post Office Telegraph Services (Mathias et al. 1924) and seriously studied from the late 1950s (Parkinson 1959, 1962; Coquelle and Mosnier 1969; Filloux 1967; Cox and Filloux 1974; Larsen 1975; Le Mouel and Menvielle 1976; Mosnier 1977).

EM seabed logging has not been considered practically in its principle without the help of sophisticated methods of interpretation, particularly those involving data inversion methods that have emerged in practice in the last decade. Without the latter, which require the provision of additional external information (including seismic data), the measures could not take all their senses.

Abrikossov I, Goutman I (1986) Géologie du pétrole. Généralités, prospection, exploitation. Ed. Mir, pp 111–114

Admundsen L et al (2006) Decomposition of electromagnetic field into up-going and down-going components. Geophysics 71(5):G211–G223CrossRef

Ambronn R (1928) Elements of geophysics as applied to explorations for minerals, oil and gas. Ed. McGraw-Hill, New York, p 177

Andreis D, MacGregor L (2008) Controlled source electromagnetic sounding in shallow water. Princip Appl Geophys J 73:21–32

Archie GE (1942) The electrical resistivity log as an aid in determining some reservoir characteristics. Petrol Trans AIME 146:54–62CrossRef

Bahr DE, Hutton J, Syvitski J, Pratson L (2001) Exponential approximations to compacted sediment porosity profiles. Comput Geosci 27:691–700CrossRef

Bannister PR (1980) Quasi-static electromagnetic fields. Scientific and engineering studies. Ed. Naval Underwater Systems Center. Newport Laboratory

Bannister PR (1987) Simplified expressions for the electromagnetic fields of elevated, surface, or buried dipole antennas. Compiled 87, vol 1, Scientific and Engineering Studies, Naval Underwater Systems Center, New-London, Connecticut

Becker K (1985) Large scale electrical resistivity and bulck porosity of the ocean crust, deep sea drilling project hole 504B. Costa Rica rift Init Rept DSDP 83:419–427

Becquerel M (1834). Traité expérimental de l’électricité et du magnétisme et de leurs rapports avec les phénomènes naturels. Ed. Firmin Didot frères

Becquerel M, Becquerel E (1847) Elément de physique terrestre et de météorologie. Ed. Firmin Didot frères, pp 655–662

Benderitter Y, Dupis A (1969) Prospection géophysique par la méthode magnéto-tellurique, vol 4. Ed. Gauthier-Villars, Paris, pp 251–273

Bitterlich W, Wöbking H (1972) Geoelektronik. Angewandte Elektronik in der Geophysik, Geologie, Prospektion, Montanistik und Ingenieurgeologie. Ed. Springer, Berlin, pp 115–117

Born M, Wolf E (1964) Principles of optics. Electromagnetic theory of propagation, interference and diffraction of light. Ed. Pergamon Press, Oxford, 808 p

Bruck R (1841) Electricité ou magnétisme du globe terrestre. Ed Imprimerie de Delevingne and Cllewaert Tome 1:41–52

Cagniard L, Morat P (1966). Extension de la prospection magnéto-tellurique à l’exploration offshore

Chave AD (2009). On the electromagnetic field produced by marine frequency domain controlled sources. Geophys J Int:29 p

Chave AD, Cox CS (1982) Controlled electromagnetic sources for measuring electrical conductivity beneath the oceans. 1. Forward problem and model study. J Geophys Res 87(87):5327–5338CrossRef

Chave AD, Luther DS (1990). Low frequency, motionally induced electromagnetic fields in the ocean. J Geophys Res 95(c5):7185–7200

Chen J, Alembaugh D (2009) Three methods for mitigating air waves in shallow water marine CSEM data. SEG Houston. International exposition and annual meeting, pp 785–789

Chouteau M, Giroux B (2006) Géophysique appliquée. Méthodes électriques. Notes de cours. Ecole Polytechnique, Montréal, p 11

Constable S (2010) Ten years of marine CSEM for hydrocarbon exploration. Geophysics 75(5):75A67–75A81

Constable S et al (2008) Mapping offshore sedimentary structure using electromagnetic methods terrain effects in marine magnetotelluric data. Geophys J Int. doi:10.1111/j.1365-246X.2008.03975.x

Coquelle J, Mosnier J (1969) Etude de l’effet « bord de mer » dans la région de Quiberon., Mémoire ENS

Cox CS, Filloux JH (1974) Two dimensional numerical models of the California electromagnetic coastal anomaly. J Geomag Geoelectr 26:257–267CrossRef

Cox CS et al (1968) Electromagnetic studies of ocean currents and electrical conductivity below the ocean floor, vol 4, part I. Ed. Willey Interscience, pp 637–693

Cox CS et al (1978) Electromagnetic fluctuations induced by wind waves on the deep-seafloor. J Geophys Res 86-Cl:431–442

d’Arnaud Gerkens JC (1989) Foundation of exploration geophysics. Method in geochemistry and geophysics, vol 25. Ed. Elsevier, Amsterdam, pp 541–559

Duroux J (1974) Procédé et appareil de prospection en mer par mesure de champ électromagnétiques. Brevet français no. 74 26465

Edwards N (2005). Marine controlled source electromagnetics: principles, methodologies, future commercial applications. Survey in Geophysics, pp 675–700

Eidesmo T, Ellingrud S, MacGregor L, Constable MC, Sinha S, Johansen FN (2002) Sea bed logging (SBL), a new method for remote and direct identification of hydrocarbon filled layers in deepwater areas. First Break 20.3 March, pp 144–152

Ellingsrud S et al (2004) Electromagnetic methods and apparatus for determining the content of subterranean reservoirs. US patent no. 6696839, Feb 24

Ellis DV, Singer JM (2007) Well logging for earth scientists. Ed. Springer, p 45 et pp 222–223

England and Wales high course (2009) Decision of justice between Schlumberger Holding Ltd and Electromagnetic Geoservices As (EMGS), p 5

Evjen HM (1938) Depth factors and resolving power of electrical measurements. Geophysics 3(1–4):78–95CrossRef

Fielding BJ, Lu X (2009) System and method for towing sub-sea vertical antenna. US patent no. 7541996, June 2

Filloux JH (1967) Oceanic electric currents, geomagnetic variations and the deep electrical conductivity structure of the ocean-continent transition of central California. PhD thesis, University of California, San Diego

Filloux JH (1987) Instrumentation and experimental methods for oceanic studies. Geomagnetism, vol 1. Ed. Jacob, pp 143–248

Fofonoff N, Millard RC (1983) Algorithms for computation of fundamental properties of seawater. UNESCO Tech Pap Mat Sci 44, 53 pp

Grand FS, West GF (1965) Interpretation theory in applied geophysics. McGraw-Hill, New York

Guegen Y (1997) Introduction à la physique des roches. Ed. Hermann, Paris

Guérin R (2007) Profondeur d’investigation en imagerie de résistivité électrique. 8^ème colloque GEOFCAN, Bondy, France, 25–26 September, pp 27–30

Guibert A (2009) Diagnostic de corrosion et prédiction de signature électromagnétique de structures sous-marines sous protection cathodique. Doctoral thesis, Université de Grenoble, 218 p

Hamon BV (1958) The effect of pressure on the electrical conductivity of the seawater. J Mar Res 16:83–86

Harrington RF (1961) Time harmonic electromagnetic field. McGraw-Hill, New York, 480 p

Heaviside O (1899). Note on the electrical waves in seawater. Electromagnetic theory, pp 536–537. Ed. E. Benn

Heshammer J, Fanavoll S, Stefatos A, Danielsen J E and Boulaenko M (2010) CSEM performance in light of well results. The Leading Edge, January, pp 258–264

Horne RA, Frystinger CR (1963) The effect of pressure on the electric conductivity of the seawater. J Geophys Res 68:1967–1973CrossRef

Ingmanson DE, Wallace WJ (1989) Oceanography: an introduction, 4th edn. Ed. Wadsworth Publishing, Belmont

Jackson JD (1998) Classical electrodynamics. Ed. Wiley, New York

Jiracek GR (1990) Near surface and topographic distortions in electromagnetic induction. Survey Geophys 11:162–203CrossRef

Johansen et al (2008) How EM survey analysis validates current technology, processing and interpretation methodology. First Break 26, June, pp 83–88

Kaushalendra Mangal Bhatt (2011) Motion induced noise in marine electromagnetic data. Thèse

Key K (2009) 1D inversion of multicomponent, multifrequency marine CSEM data: methodology and synthetic studies for resolving thin resistive layers. Geophysics 74(2):F9–F20CrossRef

Key K, Lockwood A (2010) Determining the orientation of marine CSEM receivers using orthogonal procrustes rotation analysis. Geophysics 75(3)

Kiyoshi B, Nobukazu S (2002) A new technique for incorporation of seafloor topography in electromagnetic modelling. Geophys J Int 150:392–402CrossRef

Knudsen M (1901) Hydrografische, Tabellenth edn. Friedrichsen, Hamburg, 63 p

Kong JA (1986) Electromagnetic wave theory. Wiley, New York

Kong FN et al (2009) Casing effects in the sea-to-borehole electromagnetic method. Geophysics 14(5):F77–F87CrossRef

Kraichman MB (1976) Handbook of electromagnetic propagation in conducting media. Ed. Navy Department Bureau of Ships, Appendix A.4

Kunetz G (1966) Principles of direct current resistivity prospecting. Ed. Bebruder Borntraeger, Berlin, p 9

Landau L, Lifchitz E (1969) Electrodynamique des milieux continus. Ed. Mir, Moscou, pp 150 and 352

Larsen JC (1975) Low frequency (0.1–6.0 cpd) electromagnetic study of deep mantle electrical conductivity beneath the Hawaiian Islands. Geophys J R Astr Soc 43:17–46

Le Mouel JL, Menvielle M (1976) Geomagnetic variation anomalies and deflection of telluric currents. Geophys J R Astron Soc 68:575–587CrossRef

Li Y, Constable S (2007) Marine control source: 2D marine controlled source electromagnetic modelling. Part 2: effect of bathymetry. Geophysics 72(2):63–71CrossRef

Li YG, Constable S (2010) Transient electromagnetic in shallow water: insights from 1D modelling. Chin J Geophys 53:737–742

Lodge OJ (1892) Modern views of electricity. Nature series. Ed. Macmillan, London, p 94

Loseth LO (2007) Modeling of controlled source electromagnetic data. PhD thesis, Université norvégienne, pp 167–168

Loseth LO et al (2006) Low frequency electromagnetic fields in applied geophysics: waves or diffusion? Geophysics 71(4):W29–W40CrossRef

MacGillivray PR, Oldenburg DW (1990) Methods for calculating Fréchet derivatives and sensitivities for non-linear inverse problem: a comparative study. Geophys Prospect 38(5):403–416

MacGregor L, Andreis D, Tompkins M (2007) Electromagnetic surveying for resistive or conductive bodies. US patent no. 2007/0288211, December 13

MacGregor L et al (2008) Electromagnetic surveying for hydrocarbon reservoirs. US patent no. 7,337,064, Feb 26

Meyer JJ et al (1969) Handbook of ocean and underwater engineering. Ed. McGraw-Hill, New York, p 3.38

Mittet R (2008) Normalized amplitude ratios for frequency domain CSEM in very shallow water. First Break 26:47–54

Mosnier J (1977) Le sondage magnétique différentiel. Courrier du CNRS, no. 26, October, pp 6–14

Nover G (2005) Electrical properties of crustal and mantle Rocks : a review of laboratory measurements and their explanation. Survey in geophysics, vol 26. Ed. Springer, pp 593–651

Ohm GS (1827) Die galvanische Kette, mathematisch bearbeitet. Ed. TH Riemann, Berlin, 246 p

Parkhomenko EI (1967) Electrical properties of rocks. Ed. Plenum Press, New York, 314 pCrossRef

Parkinson WD (1959) Direction of rapid geomagnetic fluctuations. Geophys J R Astron Soc 2:1–14CrossRef

Parkinson WD (1962) The influence of continents and oceans on geomagetic variations. Geophys J R Astron Soc 4:441–449CrossRef

Pavlov D et al (2009). Method for phase and amplitude correction in controlled source electromagnetic survey data. US patent no. 2009/0133870. May 28

Pirson JP (1950) Element of oil reservoir engineering. Ed. McGraw-Hill, New York, p 58

Price A, Mikkelsen G, Halmilton M (2010) 3D CSEM over Frigg: dealing with cultural noise. SEG Denver, annual meeting, pp 670–674

Razafindratsima S et al (2006) Influence de la teneur en eau sur les propriétés électriques complexes des matériaux argileux. Laboratoire IRD/UMPC

Robert M (1959) Géologie des pétroles. Principes et applications. Ed. Gauthier-Villars, pp 87–90

Rosten T, Admundsen L (2008) Electromagnetic wave field analysis. UK patent no. 2412739

Rosten T et al (2005) Electromagnetic seabed logging: a proven tool for direct hydrocarbon identification. OTC paper 17483, Houston, 5 p

Rubin Y, Hubbard S (2006) Hydrogeophysics. Water science and technology library. Ed. Springer, Dordrecht, p 196

Sainson S (2007). Inspection en ligne des pipelines. Principes et méthodes. Ed. Tec et Doc, Lavoisier, pp 231–242 and pp 73–74

Sainson S (2008) EM response to conductive structures immerged in conductive media. Confidential report

Sainson S (2009) EM subsea pipelines effect on mCSEM survey. Confidential report

Sainson S (2010) Les diagraphies de corrosion. Acquisition et interprétation des données. Ed. Tec et Doc, Lavoisier, pp 77–81

Schermber JL (2006) Identification et caractérisation de sources électromagnétiques. Application à la discrétion des moteurs de propulsion navale. Doctoral thesis, Université de Grenoble, 229 p

Seguin MK (1971) La géophysique et les propriétés physiques des roches. Ed. Les presses de l’université de Laval, Québec, p 130

Serra O (2004) Well logging, vol 1 Data acquisitions and applications. Ed. Technip, 688 p

Skilling HH (1942) Fundamentals of electric waves. Ed. Wiley, pp 118–122

Stefatos et al (2009) Marine CSEM technology performances in hydrocarbon exploration: limitations or opportunities. First Break 27, May, pp 65–71

Stratton JA (1961) Electromagnetic theory. Ed McGraw-Hill, p 314 et p 374

Sunde ED (1948) Earth conduction effects in transmission systems. Ed. D Van Nostrand, New York, p 20

Theys P (2006) Utilisations des données pétrophysiques en temps réel et pendant toute la vie d’un champ: critères de qualité et d’éthique. Communication SAID (SPWLA), Schlumberger, Clamart, 5 April

Thomsen, Menache (1954) Instructions pratiques sur la détermination de a salinité de l’eau de mer par la méthode de Mohr-Knudsen. Bulletin de l’institut océanographique, no. 1047, 30 July

Tompkins MJ, Weaver R, MacGregor LM (2004) Sensitivity to hydrocarbon targets using marine active source EM sounding: diffusive EM imaging methods. EAGE. Ed. OHM

Von Aulock W (1953) The electromagnetic field of an infinite cable in seawater. Bureau of Ships Minesweeping Branch technical report, no. 106

Walker PW, West GF (1992) Parametric estimators for current excitation on a thin plate. Geophysics 57:766–773CrossRef

Warburton F, Caminiti R (1964) Champ magnétique induit par les vagues de la mer. Bull Am Phys Soc 2(3):347

Webster AG (1897) The theory of electricity and magnetism being lectures on mathematical physics. Ed Macmillan, London, pp 534–540

Weiss CJ (2007) The fallacy of the shallow water problem in marine CSEM exploration. Geophysics 72(6):A93–A97CrossRef

Whitchead CS (1897) The effect of seawater on induction telegraphy. Physical Society

Titel: Metrology and Environment
verfasst von: Stéphane Sainson
Verlag: Springer International Publishing
Buch: Electromagnetic Seabed Logging
Print ISBN: 978-3-319-45353-8

Electronic ISBN: 978-3-319-45355-2

Copyright-Jahr: 2017
DOI: https://doi.org/10.1007/978-3-319-45355-2_3