摘要:

AbstractThe introduction of methods for recording and processing field data in digital form on magnetic tape for subsequent processing on electronic computers will result in major improvements in geophysical prospecting techniques. This offers great advantages over analogue recording such as increased dynamic range, greater filter flexibility, more convenience in processing by correlation techniques, freedom from distortion and noise, better adaptability to automatic plotting and contouring, and greater suitability for inverse convolution procedures. Digitally recorded seismic signals can be reliably transmitted long distances by telephone circuits to central data processing centers. Electronic computers facilitate processing of gravity, magnetic, and other potential field data. Smoothing, residual, correlation, and derivative techniques for handling data in digital form can enhance speed and flexibility of processing.

ISSN:0016-8025    

DOI:10.1111/j.1365-2478.1962.tb00001.x

出版商:Blackwell Publishing Ltd    

年代:1962

数据来源: WILEY

摘要:

SommaireCette publication débute par un essai de synthèse détudes antérieures relatives à la déformation d'un signal sismique, — déformation imputable, soit à la propagation dans les couches superficielles et les niveaux de transition, soit aux réverbérations d'une couche d'eau.On montre comment un modèle analogique convenable permet d'obtenir directement les réflexions et les transmissions d'une couche où la vitesse n'est pas uniforme. Les résultats obtenus sont comparés aux solutions exactes des équations de propagation et aux solutions qui résultent d'un échantillonnage de la distribution des vitesses dans la couche. Les filtres équivalents, à la propagation d'une part, et à léchantillonnage d'autre part, sont déd

ISSN:0016-8025    

DOI:10.1111/j.1365-2478.1962.tb00002.x

出版商:Blackwell Publishing Ltd    

年代:1962

数据来源: WILEY

摘要:

AbstractTechnical development and the introduction of new construction procedures has increased the number of seismic surveys carried out underground. Interesting seismic records in three components are shown and discussed. A vertical section containing results of seismic research investigations and of drilling is shown.

ISSN:0016-8025    

DOI:10.1111/j.1365-2478.1962.tb00003.x

出版商:Blackwell Publishing Ltd    

年代:1962

数据来源: WILEY

摘要:

AbstractThe coefficient of resemblance is defined in the following way:Consider a group of four traces on a seismic record. For a given timetadd the six products that can be formed by multiplication of the signal strengths recorded on two of these four traces. By doing this for all values oft, a new signal is obtained that can be smoothed by having it pass through an appropriate filter. The result of this smoothing procedure is called the smoothed coefficient of resemblance Γ.Instead of multiplying the signals of two traces at the same timet, the signal of the first trace can be taken at timet‐3θ/2, of the second trace att‐θ/2, of the third trace att+θ/2 and finally of the fourth trace att+ 3θ/2. Thus coefficients of resemblance are obtained that depend on the dip θ.For each value of θ a plotting system is triggered when Γ has a maximum with respect to time. Then a vector is plotted having a thickness proportional to Γ and a dip determined by θ. If no optical mixing takes place, the vector covers just one trace of the new vectorial registration; in case of optical mixing the vector covers a number of these traces. All vectors belonging to a certain group of traces of the seismic record appear on one trace of the vectorial presentation, so one trace includes all values of θ.Alternatively the plotting can be triggered when the corresponding sum of the signals of the four traces passes through a maximum. In this latter case the triggering can be conditioned by the maxima of Γ.The article discusses the influence of:— the optical mixing,— the integration time determined by the band width of the smoothing filter,— the method of triggering,— the way the seismic traces that have to form a group are selected (electrical mixing).A consequence of the method is that both phase alignments and energy bursts have an influence on the

ISSN:0016-8025    

DOI:10.1111/j.1365-2478.1962.tb00004.x

出版商:Blackwell Publishing Ltd    

年代:1962

数据来源: WILEY

摘要:

AbstractThe exact expressions for the reflection and refraction of homogeneous spherical compressional waves at the plane contact between two semi‐infinite media are obtained by a new simple method. Whilst its general ideas were outlined in a previous paper (Bortfeld 1962) dealing with some special interfaces, this method is now applied to all kinds of contact (solid‐solid, solid‐fluid, fluid‐solid, solid‐free, fluid‐fluid, fluid‐free). By some improvements, the treatment of the general case is even more simple than the previous one of the special cases.Integrating the potentials for sinusoidal excitation over the circular frequency and adding the static potentials yields expressions for the step‐response which consist of (infinite) single integrals of elementary functions. By a single application of Cauchy's theorem, the complete set of wavefronts is obtained and the step‐response is put into forms suitable as a basis for numerical calculations. The responses for arbitrary source excitations are given in the usual way by superp

ISSN:0016-8025    

DOI:10.1111/j.1365-2478.1962.tb00005.x

出版商:Blackwell Publishing Ltd    

年代:1962

数据来源: WILEY

摘要:

ResumeParmi les différents facteurs agissant sur l'amplitude des signaux acoustiques enregistrés au cours des mesures continues de vitesse dans les puits, le coefficient d'atténuation semble présenter beaucoup d'intérêt pour la détermination des qualités mécaniques des roches, en particulier la continuité de la matrice, donc dans une certaine mesure la perméabilité.Afin d'éliminer les facteurs secondaires agissant sur l'amplitude, nous avons été amenés à enregistrer le rapport des amplitudes aux deux récepteurs de la sonde C.V.L. Nous avons donc étudié un appareil permettant d'enregistrer les amplitudes des premières arrivées aux deux récepteurs, ainsi que le rapport de ces amplitudes.Nous présentons ici les premiers résultats obtenus par la mesure continue de l'atténuation des ondes acoustiques dans différents types de formations. Des comparaisons sont faites avec les diagraphics de vitesse, de résistivité et de radioactivité.Le log d'atténuation semble permettre la détermination de la lithologie et plus particulièrement la localisation des zones fracturées et perméables. Bien que nous n'ayons que peu d'expérience de ce nouveau type de diagraphie, il nous semble que les premiers résul

ISSN:0016-8025    

DOI:10.1111/j.1365-2478.1962.tb00006.x

出版商:Blackwell Publishing Ltd    

年代:1962

数据来源: WILEY

ISSN:0016-8025    

DOI:10.1111/j.1365-2478.1962.tb00007.x

出版商:Blackwell Publishing Ltd    

年代:1962

数据来源: WILEY

ISSN:0016-8025    

DOI:10.1111/j.1365-2478.1962.tb00008.x

出版商:Blackwell Publishing Ltd    

年代:1962

数据来源: WILEY

摘要:

Book reviews in this articleG. H. Darwin,The Tides, and Kindred Phenomena in the Solar SystemL. Cagniard,Reflection and Refraction of Progressive Seismic Waves, Translated and revised by Edward A. Flinnand C. HewittDixA. V. H. Masketand WilliamC. Rodgers,Tables of Solid Angles

ISSN:0016-8025    

DOI:10.1111/j.1365-2478.1962.tb00009.x

出版商:Blackwell Publishing Ltd    

年代:1962

数据来源: WILEY