DE2133607A1 - Method for determining the position of impedance discontinuities in a medium - Google Patents

Description

YOU-INO. CMP »L.-IMG. M-SC. DlPl. PHV "DR. ΟΙ ^. ,, - Ρ» · ^ '

HÖGER - LEGAL RIGHT-GRiESSBACH - HAECKER

PATENT LAWYERS IN S "T U TTl AR 1

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Texas Instruments Inco3 ⁱ porated 135oo Korth Central Expressway Dallas , Texas, USA

Method for determining the location of impedance discontinuities in one medium

The invention relates to a method for determining the position of jir.pedance discontinuities in a medium in which Wc-J len expand, using a variety of digital input ε Ignalörecords, each of which denotes to a recipient represents the returning energy portion of the energy introduced into the medium at a source. Particularly concerned sif.h the present invention with the generation of a Dcitenbild the discontinuities in the hedium with the help of the inventor Procedure.

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Furthermore, the invention particularly relates to such methods to determine the location of acoustic impedance discontinuities in a planet, such as the earth, with which both diffractors and reflectors can be detected.

In the past few decades, extensive research has been carried out to advance the field of seismology to achieve. Recent results show that one of the more significant developments in this field is the method of processing seismic data is disclosed in U.S. Patent 3 353 151 is described and claimed.

From this patent a method for processing seismic data is known, according to which each recording of a seismic echo. which is usually referred to as a track, W recorded by an analog or digital device operating as a full-scale Wellenfrontmustp.r is. Each coordinate point of the medium to be examined is assigned an amplitude value in the scaled wavefront pattern at a point which corresponds to the transit time of the signal from the source to this coordinate point and from this to the receiver. The amplitude values of the scaled wavefront pattern are then combined at the corresponding coordinate points, which leads to a composite image of the acoustic impedance discontinuities of the subsurface. In other words, the volume to be examined can be viewed as a three-

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imagine dimensional lattice. For each recorded source-receiver track the running time from the source to a grid point in the volume and from there to the receiver is calculated. The amplitude value of the recorded track observed at the calculated time point becomes an increasing one Adds the sum assigned to the grid point. The resulting set of values that are valid for a range of the Underground grid obtained as a result of summing the data from a plurality of source-receiver traces then high values at the location of subsoil litter areas, such as fissures, cathedral boundaries, reefs, seams, uneven areas Deposits, squeeze zones, cavities, uneven boundaries, etc. so; ie at the location of reflective interfaces. This grid Numbers can be represented in a number of common methods. The composite image thus created became has recently been recognized as a form of acoustic hologram, and the method has been recognized as a form of acoustic holography recognized.

Compared to the earlier data processing methods, the method described in the above US patent offers many advantages. Perhaps the most significant advantage is to be seen in:. Then each incremental time interval is represented in a way that corresponds to the true expansion in a two- or three-dimensional space. The method has a tendency to automatically improve the interleaving distance. They are by no UP particular restrictions on the geometry of the

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Source and recipient required. , The procedure is both Applicable for reflected as well as for scattered and diffracted energy, and makes it possible in practice in particular for first time to locate diffractors or scattering areas. On the other hand, that can be achieved by the known method Improvement of the signal-to-noise ratio not fully applied in all cases peaceful.

The present invention was therefore based on the object of further developing the method cited in the introductory description improve and in particular to propose a method for processing seismic data with which it is possible to To further improve the signal-to-noise ratio and thus to better recognize and localize both reflectors and diffraction areas.

This object is achieved according to the invention in a method of the initially described type in that, in an automatic data processing system, a data screen is generated that w a plurality of coordinate points has defining a spatial dimension, the data image is formed by the amplitude values a A plurality of traces are taken for each coordinate point, those traces being selected from the plurality of traces which are representative of the coordinate point and in that a coordinate point is derived which has an amplitude value which is representative of an impedance discontinuity.

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According to the present invention, each input track, which are either derived from a single source-receiver pair can be or can be obtained by stacking or layering the traces of a large number of source-receiver pairs, to a number of horizontally spaced apart Stations fanned out. Thereafter, each fanned track, based on the location of the source and the receiver for the entry lane with regard to the station, with regard to its deflection corrected so that each of the fanned tracks is corrected to the vertical. Then the perpendicular corrected Tracks in each interval are combined in a predetermined manner to produce a composite data image. That Data image is a coordinate grid. The value at each coordinate point the grid is a positive or negative value, and the image can be processed for display in any conventional manner will.

The invention is concerned in particular with improving the composite data image by checking the input tracks which are intended to make a contribution to certain areas of the composite data image, this control being able to take place either on a predetermined or on an automatic basis. According to a special development of the invention, the finding of similar reflectors is improved in that only a part of the vertically corrected tracks at the respective stations is selected for the combination in order to generate the composite data image on the basis of a predefined

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the given range of inclination angles of the reflectors. This selection can include a scaled mapping or weighting of the values and can change with depth.

Furthermore, in a further development of the invention, mirror-like reflectors can be emphasized by automatically increasing the amplitude values of certain vertically corrected tracks are increased j according to the degree of correspondence between the amplitude values of a certain track and the amplitude values of one or more adjacent tracks for the run times on the neighboring lanes, to those of the named ones Discontinuities if reflected energy would be found such discontinuity should exist.

Furthermore, in a further development of the invention, the image of a diffractor or scatter area, in which the amplitude values of the vertically corrected tracks are automatically highlighted be increased at each station, according to the grade the correspondence between these amplitude values and the amplitude values on one or more of the adjacent tracks the transit times at which energy from a scatter discontinuity, which lies at the point represented by these amplitude values would return.

Further advantages and details of the invention are provided below explained in more detail with reference to a drawing and / or are the subject matter the protection claims. In the drawing show:

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Fig. 1 is a schematic representation of a two-dimensional, composite data image according to the present invention ,

Fig. 2 is a schematic representation to explain a conventional Method for collecting seismic data for a larger area using the geometry of the common depth points or the method of stratification of points of the same depth, these being seismic Data can also be processed with advantage by the method according to the invention.

3 is a block diagram showing a first embodiment the method according to the present invention explained,

Fig. H is a schematic diagram showing a step of the in Fig. 3 illustrated method explained in more detail,

FIG. 5 is a schematic diagram showing a further step of the method shown in FIG. 3 in more detail explained

Fig. 6 is a schematic diagram that serves to explain in more detail the process step explained in FIG. 5 is used,

7 shows a table which indicates the tracks which the individual stations according to the method explained in FIG assigned,

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FIG. 8 is a schematic diagram which serves to illustrate the To explain criteria for the step of sector selection in the method according to FIG. 3,

Figure 9 is a schematic diagram illustrating the method of

automatic sector selection through correlation gain

ψ calculation in the method according to Fig. 3 explained,

FIG. 9 a is a schematic diagram which explains the method for determining the correlation gain in the sector selection according to FIG. ₉

Fig.Io is a schematic diagram showing the sector selection explained by automatic correlation gain determination for diffractors in the method according to FIG. 3,

Figure 11 is a block diagram of another embodiment of the Method according to the present invention,

Fig.12 is a table explaining the manner in which

the tracks at the individual stations in the process are collected according to Fig. 11,

Fig.13 is a schematic diagram showing specific aspects the method according to FIG. 11 explained,

Fig. 14

to 17 are schematic diagrams that explain in what way

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se the data shown in Fig. 13 are interpreted,

Fig. 18

to 21 shaky diagrams showing the amplitude profiles of the in Fig. 13 explains the data shown in depths Z to Z,

a d

22 is a schematic diagram showing the advantages of the Process according to the present invention explained,

Figure 2 3 is a schematic diagram illustrating another embodiment of the method according to the present invention ¹ for the automatic control sector,

FIG. 2U shows a block diagram of the embodiment of the invention explained in FIG.

Fig. 25 is a Scherr.atisches diagram showing one aspect of the Embodiment of Fig. 23 explained,

Fig. 26 is a schematic drawing showing the application of the invention Process for generating a three-dimensional data image explained,

Fig. 27 another schematic drawing showing the application the inventive method for producing a three-dimensional image for a plurality of sets of common depth point data is explained and

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Fig. 28 is a schematic diagram showing a step of the Process explained that the creation of a three-dimensional Data image is used.

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Fig. 1 of the drawing shows a typical data image as it is according to of the present invention. A baseline D forms a horizon line which, for example, is the boundary line between land and air on earth. The baseline D is divided into equal horizontal sections, at the ends of which are stations 86 to loo. It goes without saying that the data image shown in FIG. 1 is also only can be part of a larger data image. The data image is composed of a large number of coordinate points Io, which are arranged at the same vertical distance from one another below each of the stations 86-10 on the base line D. The stations on baseline D are in fact typically about 30 to 50 meters apart while the perpendicular distances between the coordinate points Io either correspond to the same time steps or the same depth steps. In both cases the vertical distances correspond however typically an actual spacing of about 7.5 to 15 meters The vertical spacings are intended below for simplicity sake, - unless otherwise stated, correspond to the depth, although it goes without saying that the invention Method can be carried out regardless of whether one is working in the time domain or in the depth domain, as is the case with the

from +

more common methods of layering / points of equal depth (common depth point stacking) takes place.

Each of the coordinate points Io is either positive or assigned negative numerical value, this fourth usually

+ or the stratification of the same - 12 -

Ί checkpoints

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Usually in - depending on the calculating machine used - digital programmed form. The value of each of the coordinate points of the data image is derived by combining several amplitude values obtained from several input tracks of Quelie-receiver pairs can be derived as follows still to be described in detail. The data image shown in Fig. 1 is of the type shown in that mentioned above "US patent is described» The present invention is now concerned with an improved method for evaluating the data to generate a data image of improved quality.

A common method of collecting seismic data, which is commonly used as a method of stratification points of equal depth is to be explained with reference to FIG. In Fig. 2, the lines loa to loc represent a land or water surface under which there is an area whose acoustic impedance discontinuities are mapped should.

It should be assumed that the seismic energy is first generated at the source S, which is commonly referred to as the shooting point, using conventional means for generating the energy, such as an explosive charge, a device for generating gas explosions, a hydraulic one Combs, a falling weight, or the like. It should also be assumed that the source S ₁ lies on a line perpendicular to the base line D through the station 90: that is

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can be on the baseline as well as above or below it. Furthermore, on one side of the source S _1, a field of catchers should be arranged along the surface or along the line loa, the receivers being located at stations 92, 94, 96, etc. The use of twenty-four receivers is typical, although only five receivers R ^ to Rc ₁ are shown in FIG. It should be pointed out that the receivers are arranged at regular intervals and that the source S ^ is typically at the same distance from the receiver R ^ as the receivers are from one another. The acoustic responses detected by receivers R ₁ through R ₅ are typically recorded along with the acoustic responses detected by the other nineteen receivers in a single twenty-four trace seismogram. Each of these tracks, also referred to as input tracks, can be identified individually by a combination of the source designation and the recipient designation, so that in the case considered here, the tracks SR to SR would be recorded. The values for each of the traces of the seismogram are preferably digital values which characterize both the amplitude and the phase position of the acoustic response determined. The digital values are typically obtained by sampling the incoming analog signal at time intervals of one, two or four milliseconds and using a single one

recorded.

The first seismogram is generated when there is a shot at the source S *

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generated. The source is then moved to station 88 and referred to as source S ₂ , and receivers R- ^ to R ₂₁ are also moved two stations at a time, as shown on line lob in FIG. 2, and it will shot again. A second seismogram with twenty-four tracks is generated,

* which are designated as tracks S ₂ R ^ to S ₂ R ₂ Ij. The source S _{3 is then moved} to the station 86, and the receivers R ^ to R are again shifted by two stations, as shown by the line loc, and firing is repeated. The shooting is repeated every two stations, the receivers being shifted accordingly until the entire area of interest is covered. It is important to recognize that the mutual location of sources, receivers and stations is actually not critical in connection with the present invention. The method of operation described above with the use of fixed distances between the stations only facilitates orderly data acquisition and processing. In general, a larger distance leads to the

'Stations that contribute to the picture lead to a larger horizontal one Resolution, and a smaller distance between the stations' provides a composite data image with a larger vertical Resolution.

The method described above for collecting seismic data is commonly called the method of stratification points same depth, and this procedure has been used for illustration of the method according to the invention selected in order to

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conditions that the method according to the invention is ideally suited, to evaluate data collected in this way, which is particularly important because large amounts of the data determined according to the known procedure are available, which can now be re-evaluated with the aid of the method according to the invention in order to obtain better information about below to preserve areas lying on the surface than was previously possible. However, it is essential that it be clarified that the inventive method does not affect the evaluation is limited by data that have been obtained by the method of stratification points of equal depth, but that it is fundamentally is applicable to all data obtained by introducing energy into a medium at a source , in which waves can propagate and that the returning energy can be received by receivers at or in this medium has established, whereby the medium in which the waves propagate, for example the earth, the human body, another solid, liquid or gaseous substance or even space, if one uses a suitable type of energy, such as electromagnetic waves that also propagate in free space.

Although the strict order of the data obtained by the method of layering points of equal depth, the data processing simplified, it goes without saying that for the Implementation of the method according to the invention no restrictions with regard to the relative position of the sources or shooting

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points and the recipient pass. The receivers do not need to be equally spaced in the hordesontal direction and the sources for the successive shots need not be evenly spaced in the horizontal direction. Moreover, it is neither regarding the Sources yet regarding the recipient required that this

P are arranged along a straight line, as required for the method of layering points of equal depth is »The sources and the receivers can therefore be arranged at any point, as long as only the coordinates of these Places fa. Are known »Furthermore, with your inventive Method a two-dimensional distribution of the sources and the receivers to generate a three-dimensional data image can be used, from which any vertical, horizontal ' Is or oblique j two-dimensional sections for a pictorial Representation can be obtained or which with the help of three-dimensional display methods, such as stereo pairs, Holograms or the usual three-dimensional drawing

fences can be displayed.

Each of the twenty-four tracks SR ₁ to S, R _{01 of} each of the seismograms that were generated by a shot at one of the sources S ₁ to S can be used as an input track for the method according to the invention to be explained with reference to FIG in all selected examples, which are discussed below, it is assumed that this is the case. It goes without saying, however, that the input

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Traces can be pretreated in practically any customary manner prior to their evaluation with the aid of the method according to the invention can, for example, by converting the coordinates of the sources and receivers to the baseline that a correction is made with regard to the upper layer (overburden or the like) or a similar method is applied will. However, for best results it is desirable to use the original tracks in the form as they are available before the method of stratification of points of the same depth is carried out, since this stratification results in the data be distorted. However, since when collecting the data for carrying out the method of stratification of points the same If a very large number of tracks would normally be generated, it may be desirable to use only a part of the total, select existing traces for processing, these traces originating from different source-receiver pairs should in order to reduce the computing time of the digital computer used to carry out the method according to the invention. For some purposes, however, you can also use the Method of layering points of the same depth, treated tracks as input tracks for the method according to the invention is used, as will be discussed below in connection with the exemplary embodiment according to FIG. 11.

Fig. 3 shows a block diagram to clarify the type and manner in which input tracks SR, SR and S ₁ R, for example with the help of a digital computer, according to an embodiment

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game of the present invention can be processed. In general, all input tracks are evaluated in parallel, as is clear from the identical, vertical flowcharts for input tracks SR SR "and S- ₁ R in FIG. 3. For example, the input _{tracks S 1} R ₉ , SR _{1 and SR 1 are} fanned out first, as indicated in blocks 2oa, 2ob and 2oc.

The process of fanning out, for example in the block 2ob, is shown in detail in FIG. 4 and consists only in the fact that the input track S ₁ R _{9 is} reproduced to generate a plurality of identical tracks S ₁ R a _Q to SR a. Since the source S _{1 was} at station 9o and the receiver R at station 94, the tracks SR a to SRa successively spread from station 9 2 over the stations with higher numbers, since station 92 is the midpoint between the Source S and the receiver R is. It is clear from the drawing that the fanning out only covers a half-space of the entire P sector in which the acoustic energy could have been received with the aid of receivers. Assuming that the acoustic speed is the same on both sides of the center of the fanning out, the tracks SRa to SRa and all further tracks derived therefrom can be reproduced, starting from station 92 and progressing to stations with a smaller atomic number. However, if the speed is not the same when propagating in different directions starting from a central point, the

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Processing of the traces S _- Ra to Si a when using other

121 12η

rer speed values are repeated, and the tracks can be designated with other indices, such as -S ₁ Ra ₁ to -S R_a. Since the tracks SRa to S Ra merely represent reproductions of the input track SR, the amplitude values for the. Propagation time T. on all

apparent ι

Traces obviously appear at the same / depth as this Fig. U shows.

The results of the steps indicated in blocks 2oa to 2oc are the tracks SRa to S ₁ R a, S ₁ R ^ ₀ to S ^ Rga and SJ a "to SRa generated by fanning, which are assigned to the individual stations according to the table in FIG. 7 are assigned.

After the splitting or unfraction of the tracks 21a to 21c, a correction takes place to take account of the deflection, as is indicated in the blocks 22a to 22c. This correction is shown in detail in FIG. 5 for the tracks which are written in the block 21b. The result of this correction process is the tracks SR b "to S ₁ R ^ b,

SR ^ b _n to S, R "b and S _-1 Rh _n to SRh, which are in blocks 23a lav on IhO inn

^ b _n to S, R "b and S _-1 Rh _n to SRh av " on IhO inn

to 2 3c are entered. Each of these tracks in blocks 23a to 23c consists of a series of amplitude values shown in uniform depth steps were scanned and thus a series of vertically spaced apart Coordinate points are equivalent. As indicated above, can

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these uniform depth steps also be uniform time steps. The depth steps for · the tracks that are in the blocks 23c to 23c are recorded, the same depth steps j are preferably those for the coordinate points Io of the composite 1 apply, although it may be desirable for some purposes to use a greater resolution achieve j by using smaller depth steps. Each of the Tracks in blocks 23a to 23c are created by correcting the corresponding track from the tracks recorded in blocks 21a to 21c to take account of the deflection or Lean according to the following equation:

CD T ₁ . =! I ζ- * Y "+ VT" + χ] ⁺ Ιίζ ^ώ + Y- ⁺ VT - χ /

V ² V5
a ^R

In this equation, Li means the distance between the source-receiver pair for the input track, T. is the propagation time up to the coordinate point (X, Y, Z) in a coordinate system, as whose origin is chosen to be the midpoint between source and receiver, with X in the direction of the baseline D is 5 Y is horizontal and perpendicular to the base line D and Z is the coordinate for the depth. V. means in the equation

the average speed at depths Z and Y ^ the effective speed at depth Z.

From equation (1) it follows that the amplitude value "which is for

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each vertical coordinate point for each of the tracks is stored in blocks 23a to 23c, is equal to the value at the propagation time T. on the corresponding input _{tracks S 1} R ^ to S ₁ Kj ₄ and thus on the fanned out tracks in blocks 21a to 21c , the acoustic energy taking the propagation time Tj_ to travel from the source S to the corresponding coordinate point and to return to the receiver for the corresponding input tracks. Since it is appropriate for most frequencies to provide vertical steps between approximately 7.5 and 15 m between the coordinate points of the tracks in blocks 23a to 23c, in some cases it will be necessary to switch between the digital values at the sampling points for the To interpolate tracks in blocks 21a to 21c in order to determine a suitable digital amplitude value for the coordinate points arranged at a corresponding vertical distance from one another.

The result of the data processing according to FIG. 5 is data which reproduce a wavefront pattern in which the amplitude values with the same propagation times in the coordinate system for the fanned out tracks lie along an elliptical bogenii 14, as shown in FIG can be viewed as a propagating wave front, which is the location: of all possible impedance discontinuities which have an influence on the acoustic energy, which according to the Au ε. Spreading time to the recording of the input tracks SR to SR Recipients. The scaled

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The wave front shape generated in the half-space between the center point and the position associated with track b corresponds to that described in the above-mentioned US patent. The tracks designated in blocks 23a to 23b also have the characteristics shown in FIG. For any given depth Z, each of the tracks S ₁ Rb _n to S ₁ R b _{3 has,} for example, an amplitude value which is equal to the amplitude value of the input track S ₁ R ₇ according to the propagation time that the acoustic energy needs to get from the source S ^ to get to the depth point Z at the station for the corresponding one of the lanes S ₁ R b to SR b and return to the receiver R2.

As already mentioned above, each input track SR is treated in the same way in order to generate a fan of vertically corrected tracks SR b to SR b, the index w for the ordinal number of the respective source and the index χ for the ordinal number of the respective source Receiver of the input track W is. The station assignments for these tracks can be seen in FIG. 7, in which the numbers in the table correspond to the index y for the track designation SRb. It can be seen that the track compartments SRb to SRb each have their center 0.11 of one of the stations 91 to 95, that the track compartments

S "R_b to S_R _r b each have their center at one of the Sta-2 1 y 2 5 y ^J *

functions 89 to 9 3 and that the track compartments S “R.b to

3 1 y

S-jRt-b their center each at one of the stations 8 7 bis 91 have. On the other hand, one appoints that each a grosce

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Number of lanes b is assigned to each of the stations. For example, the tracks S ^ bj, ^s ₁ ^ ₂ ^b 2 ^{i S} l ^R 3 ^b 3> ^S l ^R 4 ^b 4 'SjR b,, 82R ^ b ₁ , ^ 2 ^R 2 ^b O' ^ 2 ^R 3 ^b l ^{etc. <} ^ ^er station 9ο assigned. Moreover, it goes without saying that the part of the Tc cell shown in FIG. 7 contains only a small part of the total number of tracks for the respective stations,

According to the invention, the amplitude values are at successive Depth points for all or part of the tracks SRb

. w χ y

combined at each station to generate values for the to generate corresponding depth points for the composite data image according to FIG. The invention is also concerned with the way in which the amplitude values of the tracks

SR b can be combined - by the w χ y ^

Generate amplitude values in the composite data image. The combination of the amplitude values is achieved by adding a Sector selection is performed, as indicated in blocks 24a to 24c, 26a to 26c and 27a to 27c in FIG.

First of all, the processing of the data of the tracks SRb

w χ y

discussed for the purpose of emphasizing spectral reflectors will. It is recalled, for example, with regard to FIG. 5, that the amplitude four t is on an input track, for example

the track SR, after the propagation time T ₄ in the tracks SRh JO χ IjO

until S R_b is fanned out in an elliptical arc, the is the location of all possible structures that cause the acoustic waves to circulate to the receivers at this point in time.

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can know. If we now assume that the return of the acoustic If the signal is actually caused by a spectral reflector, then the spectral reflector can only be on a tangent of the arc, as is the case, for example, for the spectral reflector 3o could be the case that forms a tangent of the arc ^ in the coordinate point 32. The summation of the Amplitu ™ the value caused by the reflector at point 32 in the composite image of all other coordinate points along the arc is an error and therefore a form of noise. The present invention is also concerned with reducing or completely eliminating such noise.

Much of the seismic. Data processed in accordance with the present invention relates to geological areas in which the general range of inclination of the spectral reflectors is known. If this is the case, a large part of the noise, which is based on an incorrect arrangement of the amplitude values, can be eliminated by suitable selection of the tracks ψ SR b, which are combined at the various coordinate points of the data image. It should be assumed, for example, that all spectral reflectors in the examined area have an angle of inclination between 0 °, corresponding to the reflector 34 in FIG. 8, and a second angle which corresponds to the angle of inclination of the reflector 36. In such a case, the sector selection program 24 would be selected to have only tracks SRb through SRb from each of the

WXU WXy

fanned out tracks 23a to 23c xn the depth of the reflector '- 25 -

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For the depth corresponding to the reflector 38, the sector selection program 24 would select only the tracks SRb to SRb _{7 from each fan of the vertical tracks S w} R _x b _Q to S _w R _x b _n. It goes without saying that the same tracks are selected from each track fan, so that the sector selection programs 24a to 24c are identical. It will also be understood that the sector selection programs are designed so that the number of selected tracks increases with increasing depth in order to capture the information returning from the reflective horizons within a constant range of inclination. If the range of inclination of the reflective horizons is known within narrow limits for a given depth, the number of selected tracks to be captured in the composite image can be small for that depth. Normally, however, a larger number of tracks are evaluated with increasing depth.

The sector selection program 24 can also be used to emphasize the diffractors or source scatterers. In general, the signals returning from spectral reflectors have a greater amplitude than signals from diffractors return due to the focused nature of the reflected energy. The sector selection program 24 can thus be used in a manner opposite to that used for locating spectral reflectors to obtain the Emphasize diffractors. This means that instead of capturing only those traces SRb that may have energy

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containing returning from known reflective horizons, these traces are excluded and that instead use the remaining traces for the creation of the compound Data image are evaluated. With such a selection, only those traces would be recorded which contain energy which returns from diffractors and which is summed to map the: P diffractor, with the tendency for the perturbations, which result from incorrect scattering of the returning signals at certain reflectors cancel each other out.

The sector selection program 24 can also be selected so that. the amplitude values of the tracks SRb are weighted upwards or downwards, namely according to the distance of the respective track from that track which represents the center of the known inclination area of the boundary layers in the geological region examined. For example, when searching for reflectors in the inclination area ₃ of interest, which is assumed in FIG. 8, the amplitude values of the tracks would be

»S R b_ heavily weighted for depth 34, while the w x 2

Amplitude values of the neighboring tracks, both the. right and left would be weighted increasingly less. In the depth of the reflection 38 could be the amplitude values of the tracks S R b "and S E b. most heavily weighted while the amplitude values of the adjacent tracks would be increasingly reduced on a relative scale. In contrast, could in a search for diffractors in the geological area with spectral reflectors within the slope range that 8, the amplitude values at depth 34 of the

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Track SR \) are weighted the least, at the same time the neighboring tracks are weighted increasingly heavily, and at depth 34 the tracks SRb and SRb could be weighted the weakest and the value of the neighboring tracks could be increasingly heavily weighted.

Sector selection can also be achieved automatically using the correlation gain program for reflectors represented by block 26. For further consideration, from the tracks SR b _n to SRb, as they are in the

χ ο υ lon

9 and 9a are shown, and it is assumed in particular that the amplitude ^{value of the track s} 1 ^R 3 ^b 4 ³ ^ ^{Pun} c; t 4o is to be} processed. It is known that the energy originated from source S, station 9o, and was received by receiver Rg, station 96. The stored on the track SR _i .b _u at the point Uo amplitude value is the amplitude of the input track SR according to the propagation time corresponding to the time it takes for the acoustic energy to 4o to travel from the source S ₁ to the point in the coordinate grid system and to return to receiver R ₃ , ie generally along path 42 and 44. Given this geometry, energy would only be reflected back from a mirror-like reflector if the mirror-like reflector were in the position corresponding to dashed line 46, which is such an angle of inclination has that the angle of incidence of the beam on the reflector corresponds to the angle of reflection. If the mirror-like reflector is actually in position 46, it would

- 28 -

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BATH

A 38 942 b -> 8 <-

28.o6.71

essentially the same amplitude value 'on the adjacent input tracks SR and S.R. found. The amplitude value would found on the input track SR after the time that the energy needs to go from source S ^ to point 48 and back from there to hike to the receiver R-, which corresponds to the path 5o and 52, and the amplitude value would be on track SR found the time it takes the acoustic energy to travel from the source S. to the point 54 and from there to the receiver R return as shown by path 56 and 58. A correlation gain factor is generated by taking the amplitude value, the is stored at point 4o on the track S R.b ^, with the amplitude values of the adjacent input tracks SR and S ^ R compared will. The amplitude value stored at 4o on the track S ^ Rgbij is then made in accordance with the Correlation Gain Factor modified as described below will.

The derivative of the propagation time on the adjacent input _{tracks S 1} R ^ and SR ₁₊ is represented in FIG. 3 by the blocks 6ob and 62b. It is noted that the input track SR is fed to the block 6ob, as indicated by the line 64, and that the input track S ₁ R is fed to the block 62b, as is indicated by the line 66. A preferred method for determining the sampling time on the adjacent input tracks SR ₂ and SA is shown in FIG. 9a. If the perpendicular distance to point 4o is large compared to the distance between the receivers for the input track SR and

1 ο - 29 -

109886/1230

A 38 942 b

the receivers for the adjacent input lanes SR and S ₁ R, the approximation explained in Fig. 9a can be used with advantage. In Figure 9a it is assumed that the beam paths for wave energy returning along paths 44, 52 and 58 are parallel, as indicated by lines 44a, 52a and 58a. The exit angle of the beam 44a, namely the angle Θ, is known from the mutual relative position of the point 40 and the station 96. Due to the simple geometry, the transit time difference At, the energy returning to the receivers R and R compared to the energy returning to the receiver R is calculated according to the simple equation

A = X sin θ

where V denotes the speed of propagation. It is therefore the amplitude stored at point 4o on the track SR _{Q b}

1 ο 4

value, which is equal to the amplitude value on the output track SR

Δι 3 t)

of the adjacent track S ₁ R ₉ and compared with the amplitude value at time t) of the adjacent track SR ₁ ^ to obtain a correlation gain factor. In the example shown, the value At is negative. The value at point 4o on the

Lane SR _Q b. is then multipli-1 ο 4 with the correlation gain factor

adorns.

The correlation gain factor can be calculated in any suitable manner.

- 3o -

109885/1230

A 38 942 b

• 30- ■

be reckoned. For example, the amplitude values of all three numbers can be "algebraically summed up" and then divided by the value at point Uo to obtain the correlation gain factor. This, when multiplied by the amplitude value, results in the substitution of the sum of the three amplitude values by the amplitude value am Point Uo. On the other hand, if the three amplitude values have the same sign, the two amplitude values of the adjacent tracks can be multiplied in order to obtain the correlation gain factor, which can be a positive value anyway, so that after multiplication by the gain factor the correct one If the sign of any of the fourths is different, the values can be algebraically summed and averaged to obtain the correlation gain. Any other method of lowering the amplitude value at point 4o is also possible To derive a profit factor that is related to the degree of correlation between the selected amplitude values, any other conventional ψ correlation technique is applicable, such as a Kreuzkoi ^ relation over a short period of time. Although only two adjacent input tracks were evaluated in the example discussed above, it goes without saying that it is usually desirable to use a larger number, such as four or six, for example.

Each point on each of the tracks S ₁ R ^ b ₀ through S ₁ R ^ _n is determined in accordance with the correlation extraction method of the program

- 31 -

109885/1230

A 38 942 b
06/28/71

II

26b treated individually. The tracks obtained in this way are _{denoted by S 1} R ₃ C to S ₁ R ₃ C _n , as indicated in block '27b in FIG. Each other of the compartments from tracks SRb to

wx _# 0 SR "b is also calculated according to the correlation gain

W 5C η

drive treated to the compartments from lanes S R c_ to SRc

. wxO wxn

as indicated in blocks 27a and 27c. In these arithmetic operations, the input tracks would be S.R. and

S ₁ R- adjacent lanes for the lane fans SR b _n to SRb 1 ο l 2 U l 2 η

and the input _{tracks SR 3} and S ₁ R ₅ would be adjacent tracks for the track bins S ₁ R ^ b ₀ to SXb _n .

As already mentioned above, the tracks S Rb. to S _W R b can also be treated according to the program according to block 2 8 in order to automatically select sectors and emphasize diffractors. In this context, FIG. 10 should now be considered, which explains the treatment of the tracks SR b _n to SRb, which are shown at the assigned stations 93 to 9 8. It should be assumed that the coordinate depth point 7o on the track SR b ″ is treated to determine the correlation gain. The amplitude value stored at point 7o is equal to the amplitude value on the input track SR after the transit time, the

jL ό

the acoustic energy required to travel along path 72 from source S ₂ to point 7o and then along path 74 to receiver R ₃ . If a diffractor actually existed at point 7o, essentially the same amplitude value would appear on the adjacent input track S R_ after the propagation time required for the energy to travel along the path

109886/1230

A 38 942 b

72 to hike to coordinate 7o and return along path 76 to receiver R-. Similarly, the same amplitude value should appear on the adjacent input track SR after the travel time required for the energy to travel along paths 72 and 78 from source S ₁ to the coordinate and from there to receiver R ₁₄ . Consequently, a correlation gain factor can be generated by comparing the amplitude values on the three tracks S ₁ R ₂ , S ₁ R ₃ and S ₁ R. at the respective transit times and then multiplying the amplitude value at point 7o on track b by the correlation gain factor. The correlation gain factor can be calculated from the selected amplitude value, as was described above in connection with the calculation steps 26a to 26c. The transit times on the adjacent tracks SR and SR for the paths 62 and 76 and the paths 72 and 78 were calculated directly according to equation (1). In addition, certain approximations of the type explained in FIG. 9a are valid for certain geometric relationships. When the tracks S _- R ^ b- to SR "b

1 ^£ U 1 I η

and SjR ^ b _n to S ^ Rjb have already been calculated, the transit times from the corresponding depth points on the tracks S ₁ R ₂ b ₃ and S ₁ R ^ b ₁ can be obtained. The amplitude value stored at point 7o on track S ₁ R ^ b ₃ was the amplitude value on the adjacent input track S ^ R_ after the transit time, which corresponds to the path 72 and 76 traversed. Similarly, the amplitude value stored at the depth point 7o on track S Rb was equal to the amplitude value on the adjacent input track S ₁ R na
72 and 78 corresponds.

Input track S ₁ R according to the transit time that corresponds to the path traversed

- 33 -

109885/1230

A 3 8 9 42 b

Accordingly, for the correlation gain calculation 2 8c the appropriate amplitude values from the fan S. Rb ,. to S "R b

1 2 ü 1 2 η

can be obtained from the block 23a, as indicated in Fig. 3 by "the line 80, and the appropriate track of the fan S ₁ R b. to S, R b can be obtained from the block 23c via the line 82. These Values' can then be compared to obtain the correlation gain factor, which must be multiplied by _{the amplitude value at depth point 7o on track S 1 R b,}

J- 3 2
to get the values at depth point 7o for track S Rodn.

This procedure is used for all points on tracks SRb to

w χ 0

SRb repeats to create a fan wxn ^öö ^ wx for each input track SR

from tracks SR d _n to SRd. ¹ w χ 0 w χ η

It is important to note that at some point a diffractor such as the point 7o in Fig. Io, the energy theoretically distributed in all directions. If thus an ideal diffractor in the depth corresponding to the point 7o below of station 9 5 would actually exist, the amplitude value would be all tracks in Table 7 are those of the station 9 5 are assigned at the same depth point. Consequently, the amplitude values at the corresponding depth points on all or at least on a large number of the tracks SRb,

^{& r} w χ y '

which are assigned to the station 9 5, if so desired, are compared with one another for the purpose of correlation.

The output tracks selected by the sector selection program 2Ua to 24c, namely the tracks S Rh in the blocks 25a to

- 34 -

109885/1230

A 38 942 b

2 5c, can be combined directly to produce the composite image, this step being reflected in block 3o. This step only comprises the algebraic summation of the amplitude values of the selected tracks which are assigned to each station at the corresponding coordinate depth points, as the table according to FIG. 8 shows. Tracks ^s _w R _x c in blocks 27a to 27c or tracks SRd in blocks 29a to 29c can be combined in the same manner to produce the composite data image. The data image can then be displayed or further processed in any desired manner.

Another embodiment of the present invention is shown in the schematic block diagram according to FIG. The input tracks S R in the embodiment according to FIG.

X X-.

3 can also be used as input tracks for the embodiment according to FIG

Fig. 11 are used. As already mentioned in the introduction, the input traces -also the same by the method of stratification of points depth may be traces obtained, the 11 selected in FIG. As the input traces and designated as input traces P _u, P and P for both methods according to the invention

"0 D

are. The input track P ₁₊ is, for example, the track that is obtained by using the method of layering points of the same depth from the tracks collected according to FIG. 2, for whose source-receiver pairs the station 94 forms the center point. For example, the method would be applied to tracks SR ₉ S, R _C , S ₀ R, etc. in order to input track P.

109885/1230

A 38 942 b - 3 »-

28.o6.71 ~ vu,

produce. Similarly, the method would be applied to tracks SR ₅ , SR ₇ , ^ 2 ^ 9, ^etc. * to produce the input track P-. The input track P would be generated by the method

would be applied to the tracks for whose source-receiver pairs the station J96 is the center, these tracks would include tracks S ₁ R, SgRg, S ₃ R ₁₀ and so on. The application of the method of stratification of points of the same depth

■ for

fe actually / each of the traces leads to a correction with regard to to the normal lateral deflection and to a summation of the tracks to produce a single track, for which the signal-to-noise ratio is improved. A trace obtained by the method of layering points of the same depth is also characterized in that they theoretically locate both the source and the receiver at the common Depth point is equivalent.

In Fig. 11, input _{tracks P 14} , P ₅ and P are represented by blocks looa, loob and looc, respectively. Each of the input tracks is fanned out in the manner shown in FIG. 4, as is indicated by the blocks Io2a, Io2b and Io2c, respectively. As a result, track compartments P _u a _n to P _a , P, -a _n to P _c a and P_a _n to Pa are generated, which are entered in the blocks Io4a, Io4b and loUc. Next, the tracks in the blocks Io4a to ΙοΊο are corrected with regard to the lateral deflection, as indicated by the blocks Io6a to Io6c. This process can essentially be identical to the process discussed with reference to FIGS. 5 and 6, with the exception that

- 36 -

109885/1230

06/28/71

afc-

Probably the source as well as the receiver are for each track at the same station, with the tracks P ₁ ^ to P _ß the stations 9 H to 96 are assigned. This processing leads to tracks P ^ b ₀ to P ^ b _n , P ₅ b ₀ to P _fi b and Pgb _Q to Pb, as indicated in the blocks Io8a to Io8c. The tracks ^ in the blocks Io8a to Io8c preferably have vertical intervals which correspond to the vertical intervals of the coordinate points of the data image according to FIG. For purposes of the discussion below, it will be assumed that the perpendicular intervals are depth intervals, although equal time intervals can be used if desired. It is also understood that the vertical intervals, be it depth intervals or time intervals, can change in order to achieve better resolution in certain depths of particular interest.

Next, the tracks P ₁ b to P b, Prb _n to P _r b and P ~ b ~ to P_b are put together and compared, as in this block

»B U 6 η ■

llo suggests, so that the tracks can be put together at the appropriate stations. This compilation is shown in the table of FIG. 12, in which the stations at the upper end of the column registered in a horizontal series and in which the traces of Pb to P _n b entered in a vertical column at the beginning of the lines are. The numbers in the table stand for the index χ of the respective tracks P _Q b _x to PQ ^ · The tracks .P _Q b ₀ to ^p _o b ₁₀ , for example, start from the stations 9o to 10o. The tracks P _n b _n , P- ^ ₁ > P ₉ ^ o

- 37 -

109885/1230

A 38 942 b - ^ Π ' -

etc. to P ₁₀ ^ ₁₀ ^s ^ ^{nd at} station 9o. The blocks 112a, 112b

and 112c show the collection of tracks for stations 94,

95 or 96, as explained with the aid of the table according to FIG.

Next, a sector selection process 114a to 114c is shown the traces collected at the individual stations. When choosing a sector, the correlation gain factor becomes 116a to 116c are calculated, and the tracks subjected to the sector selection for which the correlation gain factor is calculated are then combined at 118a through 118c to obtain the values at the vertically spaced coordinate points under the individual stations 94, 95 and 96 of the data image, as indicated by blocks 12oa to 12oc is indicated.

The sector selection method 114a to 114c may be based on a predetermined one Basis, as discussed in connection with FIG. 8 became. In such a case, the correlation extraction method 116a to 116c is usually not applied.

The sector selection procedure 114a to 114c can also be used in order to select those tracks whose amplitude values are obtained using the correlation gain method described in above in Connection with Fig. Io was discussed, must be further processed. The correlation gain process can then be performed at 116a to 116c. The combination of the sector selection "

- 38 -

109885/1230

A 38 942 b

Method 114a to 114c for selecting suitable tracks P b and the correlation gain method for comparing the amplitude values for the purpose of a correlation, an automatic sector selection procedure would then include highlighting diffractors, as described above in connection with Fig. Io or a method for emphasizing reflectors, as explained with reference to FIG. 9.

It is particularly advantageous to keep the lanes at the respective stations 94, 95 and 96, as indicated by the blocks 112a to 112c, to be printed out in a graphic representation, as shown in FIG. For example, methods for generating tracks of different widths or different Densities can be used, which are of the type which are used to represent a portion of after the method of stratification data obtained from points of equal depth can be used. Such a representation can be used as an aid for the precise determination of the prevailing inclination angle of reflectors serve in the geological area of interest. It can therefore also be used to select predefined tracks, such as this has already been discussed in connection with FIG. 8 and how this is to be explained in more detail below. Fig. 13 also serves to explain a method according to which for the lanes Pb, which are assigned to the respective stations, an automatic sector selection and / or correlation gain determination takes place, as detailed below should be explained.

- 39 -

109885/1230

A 38 942 b

Figure 13 shows the traces that have been collected with respect to station 9 5, these traces being those in block 112b of FIG. 11 and which are also indicated under station 95 in the table according to FIG. It should be assumed to be at a depth Z on all tracks

el

high amplitude value occurs, as is indicated by the points 13o. The appearance of the points I3o with high amplitude on "all tracks at the same coordinate depth points shows that in the area of station 9 5 at depth Z

el

a diffractor is, as indicated in Fig. 14 by the point. This can be seen if one recalls that the amplitude value 13o occurred after a running time on the input track P and thus on the track P ₂ ^ o * While the track P _? a has been corrected for its deflection, the point 134 has been moved to the point 13o, which is indicated by the diagonal path 132 on the track Pb. Corresponding

2 «»
the amplitude value at 13o on track P _Q b _{u was} derived by transferring the amplitude value from position 136 on input track P to point 13o on track P _Q b _h . From this it becomes clear that the diffracture 13o at the same depth Z for all tracks assigned to station 95 is essentially

el

borrowed will lead to the same amplitude value. The amplitude value however, becomes for the tracks Pb in which the index y is higher is, be damped because the path covered by the energy is longer. This is of course an idealized one Representation in which it is assumed that the diffractor is point-shaped. In such a case, everyone can

- 4o -

109885/1230

A 38 942 b

HB-

Traces at station 9 5 are compared for correlation purposes, as described above.

Let us now consider a pattern of amplitude values 14oa to 14ck as shown in FIG. Amplitude values of essentially the same size and polarity are again shown at points 14oa to 14ok. This pattern of values shows that there is a reflective horizon at depth Z and that this reflective horizon has an angle of inclination of 0 °, as is indicated by the boundary layer 142 in FIG. Since the reflective boundary layer 142 is horizontal, the high amplitude signals returning from the reflective bed will _{arrive on each of the input tracks P Q} through P after the same time of flight. By collecting the tracks P b shown in Fig. 13,

x χ

the amplitude values present after this transit time are shifted to a shorter transit time on the respective tracks, as shown in FIG. The amplitude value on track P, which is reflected from point 144 of boundary layer 142, is shifted to point 14oc on track P _o b, which is assigned to station 35. The amplitude value on the input track P ₅ which is reflected from the point 148, is in the point 14oj on the track P _Q b. moved, which is assigned to the station 9 5. The amplitude value at point 14of on track P h is at the correct depth of boundary layer 142. It is noted that the amplitude value at point 14of is the deepest point in the pattern.

- 41

109885/1230

A 38 942 b

The patterns of the amplitude values 15oa to 15ok in FIG. 13 are now to be considered, it being assumed that that these amplitude values are essentially in terms of magnitude and sign are the same. These amplitude values indicate the presence of the reflective boundary layer 152 in FIG. The deepest Amplitude value 15oc on the track P b "shows the depth of the

2 3

Boundary layer at station 9 5. Since the path of propagation from the source of energy for track P b at station S2 it is known that the slope of the boundary layer is perpendicular to the direction of the propagation path 153 leading from the Station P leads to the depth point of the amplitude value 15oc under station 9 5. The points of which the high amplitude values 15oa, 15of and 15oj for the traces P .-. B. and Pb. at of the boundary layer 152 are indicated by 154, 155 and 156 in FIG.

The pattern of the high amplitude values 16oa to 16ok in FIG. 13 indicates a spectral reflector in the position 16 2 in FIG. The lowest point 16oj on track P _q b _u localizes the depth of reflector 16 2 at station 95. Boundary layer 16 2 lies perpendicular to the propagation path from point 16oj to station 99, the center of the source and receiver for input track P. The starting points of reflections 16oc, 16of and 16ok with high amplitude values are shown at 162, 163 and 164 and show how the pattern of high amplitude values 16oa to 16ok was generated.

The printing of the traces according to FIG. 13 can be used for one who

- 142 -

109885/1230

A 38 942 b

28.o6.71

this plot is analyzed in determining the range of inclination at the various depth points under a given Station, for example under station 95, can be very useful. From viewing the printed representation According to FIG. 13, the operator can see which of the tracks should be combined in order to obtain the To generate coordinate points of the final data image. The same selection is usually made for the tracks at neighboring Stations be possible. Of course, all tracks can be combined correctly to create the diffractor 13o in Fig. 14 to show. Reasonably, however, with substantially horizontal reflective boundary layers, only the tracks would of group B evaluated, while the traces of group A for inclined interfaces, as shown in FIG. 16, and the traces in group C for interfaces with a slope as shown in FIG. One recognises, that this type of selection is made in accordance with the selection of tracks referred to above in connection with the sector selection according to FIG. 8 was discussed. The graphical representation according to FIG. 13, however, provides an aid to determine the inclination at a certain station and within a certain depth range, based solely on of the data itself and without knowledge of previously recorded geological structures being necessary.

According to a further important aspect of the present invention, it will be clear from the above that the

- 43 -

109885/1230

A 38 942 b

k-116

28.o6.71

Tracks associated with a particular station, such as the tracks for station 95 shown in FIG. 13, can be automatically processed to include automatic sector selection or automatic correlation gain determination, simply by: that are drawn general patterns, in Fig. 13 A ones shown, and that the amplitude values of the individual tracks are bewichtet accordingly.

For a given depth and distance between stations, the exact pattern of the amplitude values for a plane reflector can be determined and the tracks can be scanned at any depth interval for that pattern, to determine the lowest value of the pattern, whereby it is by no means necessary that the stations are evenly spaced have from each other or are even arranged in a straight line.

Another embodiment of this invention for automatic Selecting the appropriate tracks for combination in the data image includes evaluating the degree of correlation between the amplitude values at the corresponding coordinate depths of the tracks and the weighting of the values in accordance with the degree of correlation either by evaluating or discarding the amplitude values or by modifying them the amplitude values.

-IjI ₄ - BAD ORIGINAL

109885/1230

^{A 38 9 '42 b}
k-iu6

06/28/71

For example, the amplitude values 13o in the depth Z should be considered, which in the amplitude profile according to FIG.

18 are shown. Theoretically, all amplitude values should have the same size and sign if one disregards the attenuation, -that is due to the increasing length of the propagation paths for the tracks P b with a higher index y is «As a result, there is a high degree of correlation and the combination of these amplitude values should produce a high amplitude value at the coordinate depth point Z. below the

el

Station 95 in the data image, in which one could either include all amplitude values or with one could apply a correlation gain factor as described above. Next is the amplitude profile can be viewed at the depth Z shown in FIG. Because of the general pattern of points 14oa through 14ok the amplitude profile has a maximum in the depth Z.

b at track Pb which contains the VJert 14of. Since the large

th amplitude values 14oa to 14ok on the other tracks move further beyond the depth point Z, the AmpH-

The depth values at the depth point Z of these traces normally generally decrease as shown in FIG. The amplitude profile at the depth points Z and Z is shown in FIGS.

A simple means of automatically selecting the appropriate ones Traces for a given coordinate depth in the compound Data image should also be evaluated, there is -

-4S-BATH ORIGINAL

109885/1230

^{A 38 9H2 h} ? i ?? en-r

06/28/71

rin to do a usual calculation to get the energy content of the lanes in group A, the energy content of the lanes in group 13 and the energy content of the lanes in group C to determine. Then the group of tracks that is the largest Has energy content, selected for evaluation for the composite data image. In such a procedure would for the depths Z and Z, group B, for the depth Z die

a D c

Group Λ and group C selected for depth Z.

The amplitude profiles according to FIGS. 18 to 21 are idealized and do not readily show why it is desirable to use some of the traces or the amplitude values in creating the final Omit the data image. Fig. 22 shows why it is desirable to select only part of the tracks in an area in which mirror-like reflectors predominate. Let it be assumed that each of the lanes at station 9 5 have a Is a series of digital values with equally spaced depth steps that are obtained by sampling an analog signal, which is similar to the ones shown. Those skilled in the art will recognize that three separate reflective horizons are shown and that the pattern is similar to that is, which was introduced in connection with the depth Z in FIG. 13. From Fig. 16 it is clear that only the group A traces are the only returning signals effective to form the image of reflector 152 im Bex-eich of the station 9 5 contribute. The addition of the amplitude values in depth Z for each of the tracks in groups B and

109Ö85 / 1230 bad original

28.o6.71

C forms a noise. It can be seen that an adjacent spectral reflector at a greater depth Z in the tracks of groups B and C at depth Z generates amplitude values which the boundary layer at depth Z is not in the right way

are assigned and should therefore not be included in the evaluation when the amplitude values are combined to obtain the Generate value for the coordinate point at station 9 5 in depth Z of the composite data image.

A more nifty way to automatically select the appropriate ones Tracks that are evaluated for the composite data image at the coordinate points below the respective station should be, i.e. an automatic sector control, is based on of Figures 2 3 to 2 5 explained. In view of the above discussion of FIG. 8, it will be recalled that there is a need to maintain the sensitivity to reflectors with an angle of inclination lying within a certain range is required, with increasing depth, the number of tracks that are required for the generation of the composite data image on one given station are evaluated, increase continuously. Fig. 23 shows the traces collected at station 95, what is indicated by the block 112b. One has to imagine that each of the lanes moves back to the station which is the common depth point for the respective input track, i.e. the source-receiver point. Such is the trace Pb shown for example at station 9o, which the sea

tion for input track P. From the table in iig. 12th

- 47 ORIGINAL BATHROOM

10 9 8 8 5/1230

06/28/71

it can be seen that the track P _n b is at the station 9 5.

The search for the inclination angle range between the reflective boundary surfaces 2oo to 2o2 at the depth 2g4 is now to be considered, as shown in FIG. 2 3. Energy reflected from the point at interface 2o2 below station 95 would only be found on the entry lane at station 9o, namely on entry lane P _n . The track P _n b, which is derived from the input track P and which would contain this information at depth 2o4, would be track Pb which is located at station 9o in FIG. Energy that is reflected from the boundary layer 2oo at depth 2o4 would only be found on the entry lane P for the station 8 8, and

O O

this amplitude value would be found at depth 204 on track P b. Thus, if it is desired to layer the tracks assigned to station 9 5 in such a way that the reflectors lying in an inclination area indicated between reflectors 2oo and 2o2 are emphasized, the parts of the track compartments at the different ones should be emphasized Stations in Fig. 23 which lie between the lines 2o6 and 2o8 which the tracks P ₈ gb _? and P _Q bg intersect, are included in the depth 2o4. For example, the track P- ~ .br should also be recorded between the depth 21o and the depth 2o4. The track Ρ _οο ^ should be between

DO /

the depth 2o4 and the depth 212 can also be recorded. In other words, the amplitude values in the depth 2o4 would be on the tracks P ^ b ,,. P _0O b _r and P ,, b, combined to the

ob / be) b Uo

Value of the Koox ^ dinatenpunkt under station 9 5 in the depth

- 48 -

109885/12 3 0

BATH ORIGINAL

A 38 942 b
k-146
06/28/73

2o4 for the composite data image '. If the As depth increases, other tracks are combined, and a greater number of tracks are also combined to obtain the amplitude values of the coordinate points of the data image.

In a further development of the present invention, the sector selection 114b and the correlation gain determination 116b of the method according to FIG. 11 can also be carried out automatically, as indicated by blocks 222b to 225b in FIG. The tracks assigned to station 95 are divided into a series of pie-shaped sectors which are defined by lines 2o6, 2o8 and 214 to 221. Each of these ¹ sectors can, for example, have an opening angle of 10 °, which leads to the result that the lines 2o6 and 221 each enclose an angle of 45 ° with the vertical.

The sectors are denoted by the reference numerals I to IX. The parts of the lanes Pb at station 95, which are in the sect-

/ CX.

Ren I through IX, follow, are layered around a set of angular tracks I to IX, as indicated in block 223b • is indicated. This stratification is achieved simply by the amplitude values for all tracks falling in the respective sector are selected at a given depth and that then divided by the number of values. Another suitable method for normalization or averaging can also be used for which values are applied. The number of to be evaluated Traces is thus made up of the large number of traces that

- 49 BAD ORIGINAL

109885/1230

A 38 842 b - tfa-

28.o6.71

the station 9 5 is collected - typically there are for example ninety-six tracks - on the nine angle tracks I. reduced to IX.

Next, the energy content of each of the angular tracks I to IX is calculated over a uniform depth or time interval, which depends on the shape of the data represented by the intervals i-1, i and i + 1 in FIG. the Energy calculation can simply consist of adding the squares of the amplitude values within the intervals will. The values representing the energy content of each of the angular traces I to IX in the depth interval then become compared, and a scalar value is generated for this depth interval for each of the angular tracks I to IX. It is Desired that the sum of the scalars for each interval be "1" so that the correct amplitude values in the final Data image can be obtained.

The scalars are also inclined linearly between the centers of adjacent intervals, as shown in FIG. It will Assume that the lines 228a to 228i are to be the scalars for the interval i-1 for the angular tracks I to IX, that the scalars for the interval i should be the lines 229a to 229i and that the scalars for the interval i + 1 should be the lines 23oa to 23oi should be. The scalars for the respective intervals are only applied to the amplitude values at the depth point in the middle of the respective interval, and the scalars

- 5o -

109885/1230

BAD ORlGrNAt

06/28/71

are linearly inclined from the value at the midpoint of one interval to the value at the midpoint of the closest adjacent interval. In this context, reference is made, for example, to the calars 22 8d, 229d and 23od for the angular track IV in the intervals i-1, i and i + 1. The amplitude values at the midpoints of the intervals i-1, i and i + 1 are multiplied by the respective scalar values 2 2 8d, 229d and 23od. The amplitude values between the midpoints of the intervals i − 1 and i are multiplied by a scalar, which is indicated by the line 231. Similarly, the amplitude values of the angular track IV between the midpoint of the interval i and the midpoint of the interval i + 1 are multiplied by scalars which have the values indicated by the line 232.

After the amplitude values of the angle tracks I to IX with the appropriate scalars are multiplied at each depth point, the fourth of the nine angular traces I to IX at the corresponding Depth points totaled to give the coordinate values at the corresponding depth points below station 9 5 in to generate the composite data image according to FIG. 1, as indicated by block 120b in FIG.

In the method according to FIG. 24, it is often desirable to process each of the angular tracks I to IX from step 223b to step 12ob without having access to the data in the adjacent angular sector. This can be achieved by the following method:

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The calculation of the scalar A .. is considered, which is for the Midpoint of the i-th interval of the j-th angular track at the k-th station is to be applied. The scalar is then enjoyed is calculated using the equation below:

(2)

In this equation, 0. a measure of the degree of correlation, such as the previously described energy content in the i-th interval of the j-th track of the k-th station, and OC.,

^ ik

is equal to 0 · jj · As a result, the scalar for the angular track I becomes one. The value 0- _Ik is saved for each interval.

Each of the scalars A. So the scalar A. -W _n ) »is to be applied to the η-th low point, which was measured for the middle of the i-th interval of the j-th angular track of the k-th station:

< ³ > ^A ijk (n) ^{= A} ijk ^{+ nA} ijk, (U) where η = 0, 1, 2 ... LI

(s) 'ii k ~' i +1 , j k iik

- 52 -

• r> r, «- ΒΑ ° ORIGINAL

109885/1230

Λ 38 912 b O 1 O O C Π 7

k-lM6 * I OObU /

2 8.o6.71

sz

where L is the number of depth points in the interval, ' the one between the midpoints of the i-th and i + 1st intervals were eaten.

When the scalars are calculated and on the successive amplitude values have been applied to each angular track, the resulting scalar values become a partial sum for the respective depth point added. The final value for each depth point is then after the last angle trace for the Station was added, multiplied by a restitution scalar, to get a properly weighted value for the coordinate depth point of the data image at the corresponding station, since the assumption that A = 0 = £ 0 in equation (2)

IK IxK τ ljk

for the generation of the unit value for the sum of the scalars • ^ iik ^ ^Γ J ^{e (} 3rd depth point was not valid. The restitution scalar R- _w s, which is based on the composite values of the nth iK \ η /

Depth point is to be used, the * from the midpoint of the i-th interval of the k-th station can be described by the following equation:

_R.
(6). ⁱ

(7) where η = 0, 1, 2 ... LI < ⁸ > ^B ik =? ^A ijk '

- 53-

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A 38 Ö42 b Oioocn'7

06/28/71

S3

The use of the restitution scalars leads to the values at each coordinate point of the data image at the station »die die have correct relative values. This procedure also allows the exclusion of a certain inclination area, which, for example, may contain undesirably high amplitude values, such as amplitude values caused by multiple re | flexion arise, as a function of time and depending on the station, by skipping the program and where the scalars A ... for station k, the angular

13k '

track j and the depth intervals i can be set to 0 in advance.

As already mentioned above, the method according to the present invention can be used to generate a three-dimensional data image of the velocity-impedance discontinuities of a body. Referring to FIG. 2-3, it is assumed that a volume is represented by an X, Y and Z three-dimensional coordinate system. It is also assumed that the XY plane is the reference plane which approximates the surface of the earth. Let a plurality of stations Q be arranged at coordinate grid points in the XY plane other, wave-like propagating energy is introduced into the medium at a firing point or a source S and that this energy is received at detectors or receivers R, R and R ₃ , which are arbitrarily arranged relative to the XY plane, but not in a straight line. It is also believed that the

109885/1230

k-: U6
06/28/71

SH

Energy is generated at a large number of further shooting points or sources S (not shown) and that the energy that returns with each shot is determined by a number of receivers R ₁ (not shown) that are randomly located on the XY plane are distributed so that a large number of input tracks S _W R ^ are obtained, for each of which the source and receiver are located in different places.

The input tracks S R. can then, as described above

Vi X

can be processed to produce a set of tracks S R.b using equation (1). In

In the expression S R.b, the index w denotes the position of the source, w χ xy °

the index i the location of the receiver and the index xy the cardinal values of the station Q to which the track is assigned is. According to the above, the tracks would be those of a station, for example the station Qg, those lanes such as S R.b, -. coming from the input tracks S R.

w χ 9o ° w x

are derived for which the sources and the recipients within a predetermined distance from station Q lie.

The tracks S Rb _qfi are collected by calculating the transit time from the respective source S to the successive coordinate depth points at the station and from there to the corresponding receivers R. The amplitude values on the input track SR. the amplitude values for the respective coordinate points for the

Lanes S Rb. For example, the value at the depth point ^r w is 1 xy

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ISo on the track S ^ R b _q0 equal to the amplitude value on the input track SR after the transit time, which is given by the propagation path 152 and 154. The amplitude value at point 15o on track SR, b is the amplitude value at the transit time on L input track S, .R, which is given by propagation path 152 and 156, and the amplitude value at point 15o on track S ^ Rgb _g0 ^ ^s ^ ^ ^er amplitude value on the input track SR "at the transit time, which is given by the path 152 and 158.

The tracks S Rb _v „at the station Q can before the combination ^k w χ xy xy

in a composite, three-dimensional data image can be treated by any of the methods described above. For example a sector selection, as discussed in connection with FIG. 8, can be used for both the azimuth angle and can also be carried out for the angle of inclination, in order to emphasize mirror-like reflectors, their angle of inclination in one predetermined range and which have a predetermined azimuth direction. It is also possible to exclude these reflectors to emphasize diffractors.

The automatic sector selection can be performed by correlation gain calculation methods can be achieved, as discussed in connection with Figures 9, -9a and Io. For diffractors the three-dimensional correlation gain can be determined by evaluating two input tracks for which the Sources and / or receivers are at three points,

- 56 -

109885/1230 BAD original

Λ 3 8 ¹ YN,. Ij Z 1 3 3 G Ü "7

kl »JG
28.o6.71

that are not in a straight line. For reflectors, the three-dimensional correlation gain can be obtained from each group of three input tracks can be determined for which the reflection points are not in a straight line on a possibly existing reflector.

The interpretation for automatic processing of the tracks at each station can be carried out according to the method which was discussed in connection with FIG. The echo for a diffractor is then for all tracks occur at the same depth as is the case for the returning signal 13od. The pattern of a mirror-like Reflector returning signals will reveal a substantially spherical shell, the obvious being lowest point defines the inclination and the azimuth of the inclination of the reflector at the respective station Q. The three-dimensional Data at each station can also be automatically processed in a manner as described in connection with above Fig. 13 has been described.

Generally speaking, according to the present invention, a three-dimensional Image can be derived from input tracks originating from a number of sources and receivers that at least are arranged at three points and not in a straight line as long as the coordinates of these points are known. This enables an exact mapping of structures lying below the surface in areas where there is u: i-

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it is practical to collect the data using the method of stratification from points of the same depth, such as in mountainous areas Off-road or at sea. The method can also be used to acoustically add three dimensions to the human body to map or to map industrial products in all three dimensions in order to de- | cover or any other solid, liquid or gaseous body, or any body consisting of a combination is composed of materials in these three aggregate states, to be mapped.

Referring now to Figure 24, it is further assumed that a surface area of the earth is represented by a reference plane XY, while the Z coordinate points into the volume below that surface. It should also be assumed that a grid of stations Q is arranged at uniform intervals in the XY plane. Finally suppose that three sets of data are collected for points j of equal depth, as discussed in connection with "i. aS R - aS R) US _n R ₁ - aS _n R _n >], [CbS ₁ R ₁ - bS ^) - (bS ^ - bS ^)] and "

f (cS.R. - cS.R) - (cS R. - cS R) 1. This sentences Lllln nlnnJ

of traces are hereinafter collectively referred to as aS R, bS R and

^r W χ 'WX

cS R and can be used as the input tracks

as it will be described here. Another possibility is ordering the three sets of points to be the same

- 58 -

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A 38 942 b * 5 1 O O C η 7

28.o6.7i

Depth assigned tracks aS R, bS R and cS R according to the Method of layering points of equal depth to process a single set of layered tracks P to where the index xy denotes the xy coordinates of the points of the same depth. Though the unlayered input tracks aS R, bS R and cS R in the process according to the present

W J \ W J ^ VV J ^

gender invention lead to more accurate results, as already mentioned above, it is often possible to use layered input tracks P as input tracks for the method, to reduce the amount of data to be processed. To simplify the explanation of the procedure is supposed to be adopted that the layered input tracks P are used.

Each of the input tracks P is processed to produce tracks P b through Pb which substantially _{correspond to the tracks P b r} through Th discussed above in connection with FIG. 31. These traces are collected using equation (1) and assigned as the input trace to the stations adjacent to the common depth point, as shown schematically in FIG. 28, the trace P b _Arv an

xy OU

the common depth point Q for the input track P. Calculations only have to be carried out for the tracks P b _nn to Pb in a quadrant, based on the common depth point Q, for the input track P. The same traces can be placed at the relative points in the other quadrants, assuming that the energy is in all four

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06/28/71

Quadrant around the point Q with a constant, acoustic

xy

Speed spreads. If of course different speeds must be used, separate calculations should be carried out for the tracks in the respective quadrants will.

The tracks P b _fl0 to P b can be collected at the respective stations, as was described above in connection with the table according to FIG. All traces collected at the individual stations can then be processed using any of the methods described above. Three-dimensional processing is achieved simply by evaluating data derived from at least three input tracks ρ that are at three stations that are not in a straight line.

Processing of at least two of the three sets of common Depth point data aS R bS R and cS R leads to a three-

W λ WX WX g

dimensional resolution. The use of common depth point ( data collected along parallel lines such as lines a, b and c in Fig. 27 simplifies handling and processing of the data. The common depth point lines do not need to be parallel, however, in accordance with the present case Invention to obtain a three-dimensional data image.

Fig. 2 7 shows how the usual straight forward methods of collecting of data can be used to create a three-dimensional

- 60 -

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Generate data image. It can also be seen that more complicated, two-dimensional arrangements of sources and receivers are used can be used to collect the data if so desired. For example, data generated according to the procedure were collected, which in another application of the applicant (file number ...) with the title "Dreidimensionale joint depth point evaluation "has been described, or data obtained with the devices described there, processed according to the inventive method.

The method according to the invention can be used with any digital multipurpose computer be carried out with medium to large capacity. As particularly advantageous for the implementation of the invention Process have proven digital computers that are made by Texas Instruments Inc., Dallas, Texas, under with the model name TIAC are manufactured and sold and are specially designed for the processing of seismic data of the type described above are suitable.

- 61 -

109885/1230

Claims (1)

k-146
28.o6.71 Claims Method for determining the position of impedance discontinuities in a medium in which waves propagate, by means of a multiplicity of digital input signal recordings, each of which represents the proportion of energy returned to a receiver of the energy introduced into the medium at a source, characterized in that in a automatic data processing system, a data image is generated which has a plurality of coordinate points which define a spatial dimension, the data image being generated by taking the amplitude values of a plurality of tracks for each coordinate point and with those tracks being selected from the plurality of tracks, which are representative of the coordinate point and that a coordinate point is derived which has an amplitude value representative of an impedance discontinuity. 2. The method according to claim 1, characterized in that the Plurality of tracks for each coordinate point can be derived from an input track, which on a number - 62 BAD ORIGfNAL 109885/1230 A 38 942 b 06/28/71 is fanned out by horizontally spaced stations, with the input lane either from can originate from a single source-receiver pair or by layering the traces of a plurality of source-receiver pairs can be won. 3. The method according to claim 1, characterized in that the selected tracks by scaled representation or by Weighting the fourth to be obtained. 4. The method according to claim 1, characterized in that each the coordinate points defining a spatial dimension has a composite amplitude value which is derived by calculating the time it takes for the 'wave energy is required, inter alia, from the source for each of the respective input tracks to and from the coordinate point to get to the receiver of the respective input track, and that the amplitude values of the respective input tracks increase combined with the respective calculated running times in order to generate the composite amplitude value, the composite amplitude value primarily from the amplitude values which are derived from a limited number of input tracks. 5. The method according to claim U, characterized in that the composite amplitude values at at least some of the coordinate points are essentially derived only from amplitude values obtained from input tracks - 63 - 109885/1230 28.O6.71 that have potential energy paths representative of energy returning from reflectors, whose angle of inclination is in a predetermined, limited range. G. A method according to claim 4, characterized in that the composite amplitude value is derived at each coordinate point that Bewichten by amplitude values derived from the respective input traces in a predetermined manner and that the ¹ bewichteten values are combined. 7. The method according to claim 6, characterized in that the composite amplitude value at each coordinate point by weighting said amplitude values in accordance with the position of the coordinate point with respect to the Position of the source and the receiver for the respective input3 £: pure is derived. 8. Verfanren according to claim 4, characterized in that the amplitude value of at least part of the input tracks each of the calculated transit times is a primary amplitude value, that each primary amplitude value according to the degree the correspondence between the primary amplitude value and an adjacent amplitude value of at least one adjacent input lane at the runtime on the adjacent input lane that requires the energy to travel from the source - 64 - 109885/1230 A 38 942 b 28.o6.71 le of the adjacent input track to a discontinuity through the coordinate point for the primary amplitude value leads to run and to the receiving point of the neighboring Return entry track is weighted. 9. The method according to claim 8, characterized in that the transit time on the adjacent input track is dependent on the transit time for the primary amplitude value, which is dependent on the energy path between the coordinate point for the primary amplitude value and the receiver for the input track of the first amplitude value a time A t differs. 10. The method according to claim 9, characterized in that the Time Δ t is the difference in transit time between the transit time for the first amplitude value and the transit time on the adjacent input track that the energy is required to from the source of the adjacent input track to the coordinate point for the primary amplitude value and from there to the receiver of the adjacent input track. 11. The method according to claim 9, characterized in that the time Δ t is the difference in the transit time between the transit time for the primary amplitude value and the transit time, on the neighboring one Entry track is the energy needed to go from the source to the adjacent entry track to a mirror-like one To run the reflector passing through the 109885/1230 06/28/71 ten point for the primary amplitude value runs and after the reflection to the receiver for the adjacent input track to return. 12. The method according to claim 9, characterized in that at least a part of the multitude of input traces is representative of energy which is at a common source in the media was introduced and recorded on a plurality of spaced receivers and that the adjacent input track is an input track received at a receiver that has is arranged in the vicinity of the receiver for the primary amplitude value. 13. The method according to claim 8, characterized in that each primary amplitude value of each of the respective input tracks is weighted with a correlation gain factor derived by taking the degree of correlation between each of the respective input tracks and the at least one further adjacent input track via one determined time interval. IH. A method according to claim 8, characterized in that each primary amplitude value is weighted with a correlation gain factor ox 'derived by using the primary amplitude value and the neighboring amplitude value multiplied together if the sign of the - 66 - 109885/1230 ^{A 38 9H2 b} oiiocnn 06/28/71 Values are the same, and by adding the primary amplitude value and the secondary amplitude value if
the signs of the values are different. 15. The method according to claim 4 _S characterized in that the coordinate points define three spatial dimensions. 16. The method according to claim 1, characterized in that the data image has a plurality of coordinate points that define at least two spatial dimensions that each
Coordinate point has a composite amplitude value generated by combining a plurality of weighted amplitude values so that each of the weighted amplitude values is derived by multiplying the amplitude value
on a different input track at the time it takes the wave energy to travel from the source of each of the respective input tracks to and from the coordinate point to the receiver for the respective input track · and by using each of the selected amplitude values
multiplied by a weighting factor which is a function of the depth and the horizontal distance between the sources and the receivers of the input track from which the amplitude value is selected and the coordinate point for which the
Value to be derived is. 17. The method according to claim 16, characterized in that the weighting factor decreases at a given depth when the horizontal distance increases to match the image of the reflectors to emphasize 0 1GSS8S / k-14G
28.o6.71 18. The method according to claim 16, characterized in that the weighting factor increases at a given depth, as the horizontal distance increases to emphasize the imaging of diffractors. 19. The method according to claim 1, characterized in that the plurality of coordinate points the medium in at least one dimension that defines the amplitude values for the A plurality of tracks form a set of amplitude values for each coordinate point, that each of the amplitude values of each set of the amplitude value on each other Entry track is the time it takes the energy to travel from the source for that entry track to the coordinate point and run from this to the receiver for this input track that the selection of these tracks from the A large number of traces for each coordinate point is achieved by dividing the amplitude values of the sentences into subsets ^ based on the geometric relationship between the sources and the receivers for the input track for the respective amplitude value and the coordinate point that the amplitude values according to the correspondence of the amplitude values in the subsets are weighted and that the amplitude values of the subsets are combined to generate the composite value for the coordinate point. 20. The method according to claim 1, characterized in that the - 68 - 109885/1230 28.oG.71 The plurality of coordinate points defines the medium in at least two dimensions, that the coordinate points are arranged in a plurality of essentially parallel columns, that the selection of the tracks for each coordinate point from the plurality of tracks is made by generating a set of deflected tracks for each column, that each deflected track includes an amplitude value, which is taken from the same input track ^1, namely to the time required for the energy to the coordinate point and dort'zu track to the source of this input to the receiver for that input trace run that the amplitude values of the deflected tracks at each coordinate point of each column are guarded according to the degree of their correspondence with a plurality of amplitude values on other deflected tracks of the same column and that ax weighted amplitude values at each coordinate point are combined to produce a composite value for the coordinates to generate point. 21. The method according to claim 2o, characterized in that the amplitude values corresponding to the degree of correspondence with amplitude values of other deflected tracks for the column can be moved at the same coordinate point. 22. The method according to claim 2ο, characterized in that the Amplitude values according to the degree of agreement with Am-- - GO - 109885/1230 k-146 6/28/71 amplitude values of other deflected tracks for the column are weighted at at least one other coordinate point. 23. The method according to claim 2o, characterized in that each of the amplitude values according to the degree of correspondence between the amplitude values of the subsets of the from, j steered tracks according to the geometric arrangement of the source and the receiver of the input tracks of which the corresponding deflected tracks have been derived, are grouped, are weighted. 2H. A method according to claim 23, characterized in that each of the amplitude values of the deflected tracks in each subset of tracks is weighted according to the relative degree of correspondence between the amplitude values of the deflected tracks in the respective subsets of the deflected tracks. 25. The method according to claim 2o, characterized in that each " de of the deflected tracks for each column is assigned a position generally extending from the center point between the source and the receiver for the input track from which the deflected track was derived extends parallel to the column of coordinate points to which it is assigned, and that the amplitude values correspond accordingly the degree of agreement with amplitude values - 7o - 109885/1230 A 38 9U2 b
k-146
06/28/71 th in a predetermined geometric pattern in the deflected Tracks are weighted. 26. The method according to claim 25, characterized in that that the given geometric pattern for a . gel-like reflector is representative. 27. The method according to claim 25, characterized in that the predetermined geometric pattern for a diffractor is representative. 28. The method according to claim!, Characterized in that from the amplitude values for each coordinate point a deflected track in front of each input track for each one predetermined number of stations is calculated that each deflected track amplitude values at coordinate depth points which are representative of the amplitude values on the input track at the time of flight corresponding to the Energy is required to move from the source of the input track to the respective coordinate depth point of the respective Station and from this to run the receiver for the input track that the selection of tracks from the Plurality of tracks for each coordinate point by dividing the amplitude values of the deflected tracks for each station is made into a plurality of subsets of amplitude values, with each subset the amplitude values which is generally in a piece of cake - 71 - 109885/1230 k-146
28.o6.71 shaped sector would be defined by lines which diverge from the reference point of the station generally at an angle when the deflected Traces have been placed at points that are the midpoints between the source and the receiver for the input track correspond from which the respective deflected track was »derived, that the amplitude values at the corresponding- '" the depth points within each subset as a function of the degree of correlation of the amplitude values in the subset of a depth interval in which the respective depth points are located is weighted and that the weighted values of the deflected tracks are combined to form the composite values for the coordinate depth points at the respective stations and to receive a data image. 29. The method according to claim 28, characterized in that the coordinate depth points for the deflected tracks are generally parallel columns which generally lie in an i plane. 30. The method according to claim 28, characterized in that the stations are generally arranged in a reference plane and that the coordinate depth points for the deflected Traces lie on generally parallel pillars leading from the respective stations at an angle start from the reference plane and that each subsection Am- - 72 - 109885/1230 k-146
28.o6.71 includes the amplitude values of points, which are generally in a three-dimensional area defined by at least three lines that are not in a common plane and which generally diverge with respect to the respective stations in the reference plane. 31. The method according to claim 3o, characterized in that the amplitude values by summing the squares of the values of each layered track within each of a series of Depth intervals are weighted to a power factor For each of the layered traces for the depth intervals to generate that one scalar for each layered Track is generated for each coordinate depth point, namely based on the power factor for the depth interval, in which the coordinate depth point lies that the scalars used to "convert the values of the layered tracks to weight the values of the layered tracks and that then the weighted, layered amplitude values can be combined to produce composite values for the respective coordinate depth points. 32. The method according to claim 31, characterized in that the amplitude values of the deflected tracks are subdivided in such a way that the amplitude values of each subset would generally be in segments bounded by lines that diverge from the station .. if the deflected tracks at the midpoints between the source - 73 - 109885/1 230 06/28/71 le and the receiver for the input track, from which the respective deflected tracks are derived will. 33. The method according to claim 31, characterized in that the depth intervals over which the power factors are J are calculated, are adjacent that the scalars for the coordinate depth points at the midpoints of the depth intervals are equal to the power factor for the intervals of the corresponding, layered track divided by the Sum of the power factor for the corresponding intervals for all layered traces, and that the scalars for the coordinate depth points between the centers of the depth intervals, linear interpolations between are the scalars for the depth points at the midpoints of the intervals. 34. Application of the method according to claim M for generating a ^ Datenoildes., Characterized in that each coordinate f point has a composite value derived by calculating the time it takes for the wave energy to run from the source of each of the respective input tracks to the coordinate point and from there back to the Receiver for the respective input track and also in that the amplitude values of the respective input tracks are increased the respective calculated transit times are combined to generate the composite amplitude value, the -7M- 109885/1230 k-146
28.o6.71 composite amplitude value primarily from the amplitude values derived from a limited number of input tracks. 35. Use according to claim 34 _s characterized in that the composite amplitude values of a part of the coordinate points are at least substantially derived only from amplitude values which are taken from input tracks, the potential energy pathways have, which are representative of energy returning from the reflectors, whose inclination lies in a predetermined limited range. 36. Application according to claim 35, characterized in that the composite amplitude value at each coordinate point is derived by weighting the amplitude value, which is derived from the respective input tracks in a predetermined manner and by combining the weighted values is. 37. Application according to claim 34, characterized in that the coordinate points define three spatial dimensions. 109885/1230 Blank page