ISSN:0016-8025    

DOI:10.1111/j.1365-2478.1968.tb01977.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

ISSN:0016-8025    

DOI:10.1111/j.1365-2478.1968.tb01978.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

ABSTRACTThe theory of electrical dipole soundings proved that this method can produce resistivity measurements, which are comparable with those obtained by electrical soundings of the Wenner or Schlumberger type. Their main advantage is the use of short cable lengths, which is important if the depth of penetration should be large.A considerable disadvantage of the dipole method is the great sensitivity to lateral discontinuities. Though these have an influence on the Schlumberger arrangement as well, they can disturb a dipole sounding to such an extent than an interpretation based on a horizontal layer case is no more possible.There are six different dipole arrays, which differ from each other with respect to the angle enclosed by the two dipole orientations‐the current dipole AB and the measuring dipole MN. The theoretical comparison of the dipole arrays with the Schlumberger array concerning their sensitivity to lateral discontinuities is a useful basis for the choice of the most suitable configuration.Considering geological subsurface conditions the right choice of a dipole array can give an optimal result, i.e. a dipole sounding for which the sensitivity to lateral discontinuities is as small as possible under the given circumstance

ISSN:0016-8025    

DOI:10.1111/j.1365-2478.1968.tb01979.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

AbstractThe widespread use of common depth point techniques has emphasized the need for accurate static corrections. Manual interpretation methods can give excellent results, but a computer technique is desirable because of the great volumn of data recorded in common depth point shooting. The redundancy inherent in common depth point data may be used to compute a statistical estimate of the static corrections. The corrections are assumed to be time‐invarient, surface‐consistent, and independent of frequency. Surface consistency implies that all traces from a particular shot will receive the same shot static correction and all traces from a particular receiver position will receive the same receiver correction.Time shifts are computed for all input traces using crosscorrelation functions between common depth point traces. The time shift for each trace is composed of a shot static, a receiver static, residual normal moveout if present, and noise. Estimates of the shot and receiver static corrections are obtained by averaging different sets of the measured time shifts. Time shifts which are greatly in error are detected and removed from the computations.The method is useful for data which has a moderate to good signal to noise ratio. Residual normal moveout should be corrected before estimating the statics. The program estimates the statics for correctly stacking common depth point traces but it is not sensitive to constant or very slowly changing static err

ISSN:0016-8025    

DOI:10.1111/j.1365-2478.1968.tb01980.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

摘要:

ABSTRACTDeconvolution and deringing are well known subjects and it is not necessary to state again their objectives nor the basical methods used to reach them. Let us just remember that, generally, among many others, the two following assumptions are made for simplification purposes:—for deconvolution, it is assumed that the recorded seismic signal is constant, meaning that its shape is the same all along the time interval during which the trace is to be deconvolved;—for de‐ringing, it is assumed that the ringing period is constant and that the intensity of the ringing phenomenon is independant of the time.With these two assumptions, a single constant operator can be applied for deconvolving, deringing or both. In most cases, the time variations of the signal or of the ringing are small enough and the error resulting of the application of a constant operator is acceptable. It results into a slight increase of the noise level or into a small residual ringing in the processed trace.When this noise or the residual ringing are too important, the assumption of a constant signal and ringing period must be rejected. This is the case that is examined here according to the following steps:—short definition of the problem;—fast evaluation of some possible solutions;—the selected solution: resulting approximations and how to obviate them, computing method and a remark about the operators;—theoretical example: the efficiency of the process used is evaluated on data in which the results aimed at are known; the influence of the selection of numerical values to be assigned to the parameters is examined;—real cases: comparison of results obtained with the Protee process and with more conventional processes assuming a time invariance or including a weighted composition of several conventional processes each with a dif

ISSN:0016-8025    

DOI:10.1111/j.1365-2478.1968.tb01981.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

ISSN:0016-8025    

DOI:10.1111/j.1365-2478.1968.tb01982.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY

ISSN:0016-8025    

DOI:10.1111/j.1365-2478.1968.tb01983.x

出版商:Blackwell Publishing Ltd    

年代:1968

数据来源: WILEY