Abstract: Systems, methods, and computer-readable media for attenuating guided waves in seismic data using polarization filtering are provided. A raw hydrophone component and raw geophone component of multicomponent seismic data may be scaled using a constant scalar to enhance the ellipticity ratio of guided waves. Polarization filtering based on the ellipticity ratio may be applied within a velocity constraint to the scaled hydrophone and vertical geophone components to attenuate the guided waves. Additionally or alternatively, polarization filtering based on the tilt angle may be applied within a velocity constraint to the raw hydrophone and vertical geophone components to attenuate the guided waves. Polarization filtering may be applied to a raw hydrophone component and raw vertical geophone component of seismic data to attenuate Scholte waves before attenuation of the guided waves.

Abstract: Recorded seismic data includes seismic traces having respective source orientation angles, where the source orientation angles represent deviations in seismic source orientation relative to an inline survey direction. A plurality of designature operators corresponding to respective designature orientation angles within a defined set of designature orientation angles may be generated. For a given member of the defined set of designature orientation angles, a corresponding designature operator may be applied to the recorded seismic data to generate designatured seismic data for the given designature orientation angle. For a given seismic trace having a given source orientation angle, the designatured seismic data may be interpolated to generate a designatured version of the given seismic trace. The results may be stored in a tangible, computer-readable medium.

Abstract: Methods, systems, and apparatus, including computer programs encoded on computer storage media, for processing database system processes seismic wave data using database queries. The seismic wave data is obtained from sensors of a reflection seismology survey. The seismic wave data is distributed among nodes of the parallel processing database system. Computations of processing the seismic wave data are performed using relational database queries that execute on the nodes in parallel. These computations performed by the queries include generating a starting Earth model of an area surveyed, and performing iterations of solving a forward problem of generating seismic wave patterns from the starting Earth model, performing local optimization that modifies the starting Earth model, and providing the modified Earth model as input to the forward problem in a next iteration.

Abstract: During a seismic survey, shots located close to one another are fired at a time interval shorter than an echo time interval and longer than a closest receiver time interval. During the echo time interval which follows a first shot, receivers located within a predetermined distance from the first shot location detect seismic reflections related to the first shot. During the closest-receiver time interval which follows the first shot, at least one seismic receiver located closest to the first shot location detects all the reflections from the first shot reaching this seismic receiver.

Abstract: The transmission system combines a self-contained, wireless seismic acquisition unit and a wireless, line of site, communications unit to form a plurality of individual short-range transmission networks and also a mid-range, line of sight transmission network.

Abstract: Method, computer device and software for calculating a corrected temporal variation (dt1)depth or a corrected relative temporal variation (dt1/t1)depth of a first body wave based on a second body wave. The method includes receiving raw seismic data recorded with a receiver; calculating arrival-time variations for the first and second body waves; calculating first and second relative temporal variations for the first and second body waves; and correcting the first relative temporal variation based on the second relative temporal variation to obtain the corrected relative temporal variation or correcting the first temporal variation based on the second temporal variation to obtain the corrected temporal variation. The second wave is either a body wave or a surface wave.

Abstract: Method, computer device and software for calculating a corrected temporal variation (dt1)depth or a corrected relative temporal variation (dt1/t1)depth of a first body wave based on a second body wave. The method includes receiving raw seismic data recorded with a receiver; calculating arrival-time variations for the first and second body waves; calculating first and second relative temporal variations for the first and second body waves; and correcting the first relative temporal variation based on the second relative temporal variation to obtain the corrected relative temporal variation or correcting the first temporal variation based on the second temporal variation to obtain the corrected temporal variation. A body wave is a wave that experiences at least one reflection before being recorded by the receiver.

Abstract: This invention is for a method for transforming a seismic trace into a compressed domain. The seismic source wavelet is transformed into a zero degree phase wavelet and a shifted 90 degree phase wavelet, and the two wavelets span a 2-dimensional sub-space. A dictionary is created by collecting the wavelets in the sub-space. In practice this dictionary is usually combined with conventional existing wavelet dictionaries. The seismic trace is projected onto the dictionary (sub-space alone or combined) to find the best matching projection, with a residual determined after each projection, wherein the sum of the residuals determines the fidelity of the data compression.

Abstract: A method, having application to petroleum exploration or production, for picking the arrival time of seismic waves and use thereof for orienting the components of a multi-component sensor. After acquisition of seismic data using a VSP type method, with a multi-component sensor, a module signal is constructed by calculating the square root of the sum of the squares of at least two orthogonal seismic components. Arrival times of a direct seismic wave are then picked on an amplitude extremum of this module signal. Based on this picking, the seismic components can then be oriented in a unique reference frame whatever the depth of the sensor. A time window is defined on either side of the picked arrival times and the azimuthal direction is determined by maximizing the energy of the horizontal components within this time window. Finally, the three components are oriented in a reference frame defined with respect to the azimuthal direction, which is identical for each depth.

Abstract: Methods and apparatus are provided related to seismic sensor data. Seismic sensor signaling is digitally sampled in accordance with a local clock and without synchronization to standardized time. Timestamp data is used to synthesize data correspondent to an artificial stimulus waveform. Cross-correlation of the synthesized data with the seismic sensor data yields a correlation result. The correlation result can be scaled to an original starting time for the seismic data sampling. The scaled correlation result can be stored in computer-accessible media and subject to further processing or interpretation.

Abstract: Systems and methods for asynchronously acquiring seismic data are described, one system comprising one or more seismic sources, a plurality of sensor modules each comprising a seismic sensor, an A/D converter for generating digitized seismic data, a digital signal processor (DSP), and a sensor module clock; a seismic data recording station; and a seismic data transmission sub-system comprising a high precision clock, the sub-system allowing transmission of at least some of the digitized seismic data to the recording station, wherein each sensor module is configured to periodically receive from the sub-system an amount of the drift of its clock relative to the high precision clock. This abstract is provided to comply with rules requiring an abstract to ascertain the subject matter of the disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. 37 CFR 1.72(b).

Abstract: A device, medium and method for de-blending seismic data associated with a subsurface of the earth. The method includes receiving blended seismic data, wherein the blended seismic data includes traces having energies from two or more different shots that partially overlap; applying an apex-shifted radon transform (ASRT) to the blended seismic data to transform it from a first domain to a second domain; applying a mute processing for removing all shots except a first shot in the second domain; applying a reverse ASRT to the given shot to obtain the first shot in the first domain; and generating an image of the subsurface based on the first shot in the first domain. The procedure may be iteratively repeated to separate all shots.

Abstract: The invention is a method for extrapolating missing near-offset seismic data (101) so that the data may be used, for example, in SRME or another multiple-reflection elimination method. The invention uses the reciprocity principle (102) to relate two seismic states (acoustic or elastic) that can occur in a time-invariant, bounded domain in space. One of these states represents the physical experiment for the acquisition of the actual seismic data where near-offset traces are missing, and the other state represents a synthetic experiment with no missing near offset traces, computer-generated on a much simpler earth model. The reciprocity relationship used to relate these two states is iteratively inverted for the missing near-offset traces (103), preferably using only part of the synthetic data (102) so as to reduce inversion artifacts. The reference model acts as a constraint on the near-offset extrapolation.

Abstract: Described herein is a land seismic data acquisition system comprising a central processing unit; a cabled network connected to the central processing unit comprising a plurality of acquisition lines each comprising: electronic units assembled in series along a telemetry cable and each associated with at least one seismic sensor, the units processing signals transmitted by the sensor(s); intermediate modules assembled in series along the telemetry cable and each associated with at least one of the electronic units, each intermediate module providing power supply and synchronization of the electronic unit(s) wherewith it is associated; wherein each electronic unit is associated with at least two intermediate modules including at least one upstream and at least one downstream from the electronic unit along the telemetry cable, and comprises synchronization means independent from the cabled network, bidirectional and autonomous power supply means, bidirectional storage means of the signals processed by the electr

Abstract: A method for interpolating irregularly sampled seismic data, including receiving seismic data acquired at irregularly spaced seismic sensors in a survey area, defining a plurality of regularly spaced locations in the survey area, forming an annular ring around one of the plurality of regularly spaced locations, and interpolating the seismic data inside the annular ring to estimate seismic data that would have been acquired at the one of the plurality of regularly spaced locations.

Abstract: Seismic data representing the propagation of seismic energy through a geologic volume of interest is processed. The seismic energy propagates through the geologic volume of interest from one or more source locations at or near the geologic volume of interest to one or more detector locations at or near the geologic volume of interest. In processing the seismic data, the seismic energy is modeled as beams (e.g., Gaussian beams). The processing includes determining a filter for the seismic data that attenuates aliasing which may be present in the seismic data due to spacing between detector locations.

Abstract: An estimated frequency-wavenumber spectrum is generated by applying a first Anti-leakage Fourier transform method to unaliased frequency components in temporal-transformed seismic data and applying a second Anti-leakage Fourier transform method to aliased frequency components in the temporal-transformed seismic data. The second Anti-leakage Fourier transform method applies an absolute frequency-wavenumber spectrum extrapolated from unaliased frequencies to aliased frequencies to weight frequency-wavenumber components of the aliased frequencies. An inverse temporal and spatial Fourier transform is applied to the estimated frequency-wavenumber spectrum, generating trace interpolation of the seismic data.

Abstract: Diagonal gather trace interpolation systems and methods are disclosed. In some embodiments, the method includes obtaining seismic traces from a marine seismic survey performed using typically two seismic sources fired in a flip-flop pattern. The seismic traces are processed in common field file trace groups from each cable by performing trace interpolation in opposing diagonal directions. Among other things, diagonal trace interpolation may improve azimuthal regularization. In any event, the disclosed interpolation methods maintain spatial bandwidth increased spatial resolution with increased inline and crossline sampling components. Diagonal gather trace interpolation exploits reduced input trace separation to provide improved stability and detection of a greater range of formation dip angles. After interpolation and regularization, the seismic traces may be imaged and interpreted for improved seismic exploration and monitoring.

Abstract: Systems and methods for asynchronously acquiring seismic data are described, one system comprising one or more seismic sources, a plurality of sensor modules each comprising a seismic sensor, an A/D converter for generating digitized seismic data, a digital signal processor (DSP), and a sensor module clock; a seismic data recording station; and a seismic data transmission sub-system comprising a high precision clock, the sub-system allowing transmission of at least some of the digitized seismic data to the recording station, wherein each sensor module is configured to periodically receive from the sub-system an amount of the drift of its clock relative to the high precision clock.

Abstract: Diagonal gather trace interpolation systems and methods are disclosed. In some embodiments, the method includes obtaining seismic traces from a marine seismic survey performed using typically two seismic sources fired in a flip-flop pattern. The seismic traces are processed in common field file trace groups from each cable by performing trace interpolation in opposing diagonal directions. Among other things, diagonal trace interpolation may improve azimuthal regularization. In any event, the disclosed interpolation methods maintain spatial bandwidth increased spatial resolution with increased inline and crossline sampling components. Diagonal gather trace interpolation exploits reduced input trace separation to provide improved stability and detection of a greater range of formation dip angles. After interpolation and regularization, the seismic traces may be imaged and interpreted for improved seismic exploration and monitoring.

Abstract: Diagonal gather trace interpolation systems and methods are disclosed. In some embodiments, the method includes obtaining seismic traces from a marine seismic survey performed using typically two seismic sources fired in a flip-flop pattern. The seismic traces are processed in common field file trace groups from each cable by performing trace interpolation in opposing diagonal directions. Among other things, diagonal trace interpolation may improve azimuthal regularization. In any event, the disclosed interpolation methods maintain spatial bandwidth increased spatial resolution with increased inline and crossline sampling components. Diagonal gather trace interpolation exploits reduced input trace separation to provide improved stability and detection of a greater range of formation dip angles. After interpolation and regularization, the seismic traces may be imaged and interpreted for improved seismic exploration and monitoring.

Abstract: A seismic processing method of the migration type, comprising the steps of: linearly combining downgoing waves generated at a plurality of shotpoints, and also upgoing waves recorded by a plurality of seismic sensors; notionally propagating the composite waves as obtained in this way in order to obtain migrated downgoing and upgoing waves for different depths; and determining at a plurality of depths at least one characteristic of the subsoil as a function of the upgoing and downgoing waves propagated in this way; the downgoing (resp. upgoing) composite waves being calculated by a linear combination of downgoing (resp. upgoing) waves in which said downgoing (resp. upgoing) waves are weighted by the coefficients of a spatial modulation matrix which is a function of the positions of the shotpoints.

Abstract: A method includes conditioning a set of multicomponent seismic data and sensor orientation data, the multicomponent seismic data including pressure data and particle motion data, acquired in a towed array, marine seismic survey; digital group forming the conditioned pressure data, a vertical particle motion component of the conditioned particle motion data, and the conditioned sensor orientation data; and summing the digitally group formed pressure data and the digitally group formed vertical particle motion component.

Abstract: A wireless hydrophone system includes a hydrophone joined to a preamplifier. A serial A/D converter receives the amplified hydrophone signal and provides a serial digital output representative of the signal. The A/D converter is joined to a processor which provides a start signal and a clock signal to the A/D converter. A digital transmitter is also controlled by the processor. The transmitter receives the serial digital output from the A/D converter for wireless transmission over an antenna. The system can also include logic for allowing the processor to provide an extended sync signal for transmission. The extended sync signal can alert a receiver to an initial transmission. The system can be incorporated in a hull treatment for positioning on a vessel's hull.

Abstract: The present invention provides a method and apparatus of acquiring and processing seismic data. One or more controllers are each coupled to seismic sensors and to each other to form a network of data acquisition units. A main controller is coupled to a crossline unit via a cable comprising a synchronizing conductor and one or more power/data conductors. Commands and data are packaged such that multiple routings are possible without affecting final calculations. Each crossline unit is capable of accepting a fiber optic input, a wire input or a combination.

Abstract: Methods and systems are provided for acquiring seismic data. Data are collected representing acoustic signals received from the Earth at distinct geographic locations. Data representing an ambient signal at the distinct geographic locations are also collected. For each of the geographic locations, a known time dependence of the ambient signal is correlated with a time dependence of the collected acoustic-signal data to define time-correlated acoustic signal data. The collected acoustic-signal data for the distinct geographic locations are synchronized from the time-correlated acoustic-signal data.

Abstract: A seismic data acquisition module includes a motherboard that is environmentally protected as a independent unit by an integral sheath, envelope or encapsulating cover. The motherboard unit is suitably configured for rapid and frequent manual removal from the interior cavity of a protective outer housing for compact and more secure packaging as well as more convenient transport over great distances, if necessary, to successively different survey sites. At a new survey site, the motherboard units may be inserted into more bulky but also more rugged or waterproof outer housings that are provided with environmentally tight cable connectors. The outer housings, having a capital value of only a fraction of the electronic motherboard units, may have arrived at the new site at a different time and may even be distributed in the new survey field at the time the motherboard units arrive.

Abstract: Seismic imaging apparatus for receiving data propagated through sub-surface structure from a seismic source to at least one seismic receiver and forming an image therefrom, the apparatus comprising: an imager for forming an initial image from said data including initial locations of seismic features indicated in said data, a migrator, associated with said imager, for carrying out seismic migration over at least two layers or depth levels to provide corrections to said initial locations, said migrator comprising a krylov space expander for carrying out a krylov space expansion of the exponent of a square root operator, the operator being for defining a wave propagation between respective layers, and a corrector, for using said corrections with said initial locations to form a seismic image indicating said features.

Abstract: Seismic imaging apparatus for receiving data propagated through sub-surface structure from a seismic source to at least one seismic receiver and forming an image therefrom, the apparatus comprising: an imager for forming an initial image from said data including initial locations of seismic features indicated in said data, a migrator, associated with said imager, for carrying out seismic migration over at least two layers or depth levels to provide corrections to said initial locations, said migrator comprising a krylov space expander for carrying out a krylov space expansion of the exponent of a square root operator, the operator being for defining a wave propagation between respective layers, and a corrector, for using said corrections with said initial locations to form a seismic image indicating said features.

Abstract: A product-sum operation portion for performing a product-sum operation (wavelet transformation) with respect to an input time-series signal by using as a base of integral a complex function in which the imaginary number portion is &pgr;/2 shifted in phase from the real number portion, a phase calculation portion for calculating a phase &thgr; from the ratio between the real number portion and the imaginary number portion of a result of the product-sum operation, a peak time detection portion for detecting a time point at which the calculated phase &thgr; changes from 2&pgr; to zero, as a peak time, are provided. Since the wavelet transformation is performed by using a basic wavelet function that is localized in terms of time and frequency, a peak time can be promptly detected. Furthermore, since a differential operation is not employed but the product-sum operation is performed, false detection caused by noises or the like can be prevented.

Abstract: A method for analyzing and classifying the morphology of seismic objects extracted from a 3D seismic data volume. Any technique may be used to extract the seismic objects from the 3D seismic data volume. According to the inventive method, one or more morphologic parameters are selected for use in classifying the morphology of the selected seismic objects. Geometric analyses are then performed on each seismic object to determine geometric statistics corresponding to the selected morphologic parameters. The results of these geometric analyses are used to classify the morphology of the seismic objects according to the selected morphologic parameters.

Abstract: A method of processing seismic signals for the analysis of moveout is presented in which waves are transmitted in a medium, reflected, received by receivers and recorded in the form of seismic traces. A string of N integers is defined having indices j lying between two limits (j.sub.min, j.sub.max) and representative of the moveouts of at least one predetermined gather of traces. A focus depth time t.sub.p for each value of j is calculated. A string of P integer numbers u is defined which determines an interval (P-1).DELTA.X. For each value of j, each trace identified by its parameters X.sub.0 and h is copied as many times as there are integer numbers u in the interval (P-1).DELTA.X. At least one static correction (dt) is applied to each of the copied traces, dependent at least on the parameters j, h and u .DELTA.X. Copying and static correction are repeated for all the values of X.sub.0 and of j.

Abstract: A system and survey method for estimating the geodetic position of acoustic sensors placed at fixed but unknown locations on the seafloor is disclosed. Bottom mounted sensors are surveyed using an extension of the well known trilateration survey technique, i.e., making ranging measurements from reference points to the point to be surveyed. For acoustic sensors, these ranging measurements are obtained by transmitting an acoustic signal from a near surface projector and making corresponding timing and/or position measurements, requiring calculation of the Effective Sound Velocity. Bias errors are precluded from propagating to the sensor coordinates by considering timing and sound velocity biases, in addition to the sensor coordinates, as parameters to be estimated.

Abstract: A process for separating waves in borehole seismics for walkaway-type acquisitions. Waves are generated in a medium from several positions of a source. The waves are received at at least three sensors along axes V, H.sub.1, H.sub.2. Collections of C traces are formed with a common source. On the basis of the trace collection, collections of residual C traces and C signals, a pivot trace is selected from the collection of residual C traces. A straight line of variable slope p is plotted at each sampled point of the pivot trace. The amplitudes of the seismic events located at the intersections of the traces with the straight line are summed along the straight line. The amplitude sums are then transferred to a domain (.tau., p). A synthetic seismogram is made from the domain (.tau., p) and iterations are performed until the synthetic seismogram is acceptable in terms of the data of the collection of residual C traces.

Abstract: The present invention provides a method of migrating seismic records that retains the information in the seismic records and allows migration with significant reductions in computing cost. The present invention comprises phase encoding seismic records and combining the encoded seismic records before migration. Phase encoding can minimize the effect of unwanted cross terms while still allowing significant reductions in the cost to migrate a number of seismic records.

Abstract: Marine seismic data sets are generally under-sampled spatially because of the relatively long listening times required in deep water. It is customary to use very long spreads in the field thereby enhancing aliasing and interference from coherent noise. A seismic-signal data processing method is proposed that applies a combination of a forward parabolic Radon transform and a linear Radon transform to the data, followed by a further transform to a three-dimensional frequency domain. In this domain, a deterministic operator is applied to the data to sharpen the Radon-domain response thereof. The data are then scavenged of noise in the Radon domain and inversely transformed back into the time-space domain.

Abstract: A method for generating an unaliased 3-D DMO operator using two dimensional sampling theory to the spatial traverse of the operator as well as to the temporal axis. First a continuous DMO operator is generated along the line segment connecting a source and a receiver directed at an arbitrary azimuth relative to a biaxial output grid. The operator is discretized at spaced-apart sample points along the DMO aperture segment, the spacing being equal to or less than the output grid dimensions. A exponentially tapered sinc filter function is applied to the samples which are then interpolated onto the output grid.

Abstract: A method for improving seismic sections includes generating seismic signals at source stations, recording seismic traces at receiver stations and gathering the seismic traces as a first gather at a common point as a function of the offsets between the source stations and the receiver stations. A common point (MMOCMP) is selected, a half-offset between source and receiver stations is redefined as a function of the distance between the selected common point MMOCMP and the RAWCMP, and the seismic traces are sorted as a function of the redefined half-offset, constituting a second gather of traces. The method permits one to obtain true located subsurface information at any desired point for velocity analysis.

Abstract: A method of seismic shot-record migration includes the steps of generating seismic or acoustic waves into an earth formation from one or more sources with the sources being spaced some finite distance from each other. Next, one or more spaced receivers receive a seismic signal after the signal reflects or diffracts off of a subterranean feature. Next, a source location and a receiver location is arbitrarily selected. Finally, input data is mapped or migrated according to one of two equations, or both equations, to produce output data. The output data is then suitable for further processing by other seismic analysis techniques.

Abstract: A multi-dimensional assemblage of time/velocity functions are sampled for velocity as a function of incremental time. The samples are stored in a matrix arranged in columns along the time axis and rows across the velocity axis. The count of the number of samples resident in the respective cells of each row is indexed. A desired statistical operator is applied to the count indices in the rows to provide a family of filtered histograms in time-sequential order. The filtered histograms may be edited by delimiting acceptable velocities to lie between preselected percentiles.

Abstract: The present invention provides method of interpolating spatially aliased seismic data. This method produces high resolution interpolated data based on a locally planar model of reflection events using a two dimensional power diversity slant stack process that transforms the data from the t-x-y domain to t-xslope-yslope domain. The present invention further provides an improved technique for the 3D interpolation of aliased events and is applicable to the interpolation of 2D seismic data.

Abstract: A method by which portions of a seismic data set are deleted since no meaningful data is contained in that portion contains the step where a line of data is examined, gather by gather, to determine the smallest useful arrival time for every offset. Data having an arrival time smaller than its useful arrival time is eliminated. In addition, the present method provides a manner of storing traces in pairs. In this method, the total number of traces is mathematically folded in half, storing the last trace with the first trace, etc. In an alternate embodiment, disk saving can be achieved by storing all the traces end to end in a single record and keeping track of the starting point and the length of each trace. The proposed method works for either SHOT or CDP gathers. Each line of data is examined, gather by gather, and the smallest useful arrival time is recorded for every offset.

Abstract: An encoded seismic source, such as a marine vibrator, and a receiver, such as a seismic streamer, are pulled through water at constant velocity and depth. The source is periodically actuated and the reflected acoustic signals are converted by the receiver into seismic data. The seismic data are transformed to a fixed reference frame relative to earth before being processed.

Abstract: A method in real time control systems for seismic interference to indicate an acceptable level of interference in relation to the amplitude, angle of incidence, and frequency of a seismic reflection signal, and to remove such interference loaded signals during seismic surveys, comprises steps to determine lower threshold values of coverage, identify interference and amplitude anomaly in the recorded signal of reflection, estimate the expected value of amplitude characteristic of the signal on the basis of recorded amplitude characteristics of recorded signals from one or a plurality of preceding series of survey, mark time windows in which interference and/or amplitude anomaly are identified, generate a table of the number of times a certain time window was marked in the series of recordings of the same point of reflection, assign limits on the number of interference events to various marked time windows, and remove from the recordings those time windows wherein the number of interference events exceeds the l

Abstract: A method for seismic trace interpolation by dip range analysis is disclosed. In the preferred embodiment, a series of dip ranges are defined by a plurality of dips. A trace estimate for each of the dip ranges is generated by filtering with a mathematically integrated time shift in each frequency component of each seismic trace appearing in the dip range. These filtered frequency components are then passed through a low pass filter. The sum of the filtered frequency components is the trace estimate. The seismic traces are then demodulated to obtain the trace envelopes whose values along the above mentioned dips are examined for continuity. A continuity factor is developed for each dip and then each of the continuity factors is summed and the sum divided by the number of continuity factors to obtain a weighting function. The weighting functions are multiplied with the trace estimates, and the results summed to obtain the interpolated trace.

Abstract: An array of Radon transform processors accepts signals representative of the x and y positions of each pixel of an image together with signals representative of the magnitude or brightness of the image. Each Radon transform processor of the array is associated with one value of .theta., an angle relative to the x-axis, and each processor is associated with a different .theta.. Each radon transform processor multiplies the current value of x by cos .theta. and the current value of y by sin .theta., and adds the products to produce the value of rho, the distance from the image center along a line at angle .theta., at which each pixel contributes to a line integral. A memory stores the current pixel's magnitude by updating the line integral associated with the current value of rho by adding the pixel magnitude. When all pixels of the image have been evaluated, the memory of each processor of the array is read in sequence, and the value of the line integral for each value of rho is read from each memory.

Abstract: A method is described for enhancing seismic data and, more particularly, for attenuating multiple reflection events in seismic data. Seismic data are sorted into common endpoint gathers, and selected multiple reflection events are corrected for time delays associated with the reflection of the seismic energy from common reflecting interfaces and aligned. The aligned multiple reflection events are attenuated and the resulting enhanced seismic data can then be inverse time-delay corrected for subsequent processing, including repetitions of the aligning and attenuation steps to suppress additional multiple reflection events in the seismic data.

Abstract: A method for removing noise from seismic wiggle traces is provided. Data points from the seismic traces are selected for which amplitude and derivative values are determined. The derivative values are crossplotted as a function of the amplitude values. A rejection line is then selected on the crossplot wherein all data points which plot outside of the rejection line are treated as noise, such data points being assigned a new amplitude value to thereby remove the noise from the seismic traces.

Abstract: A common bandwidth determination method for two disparate seismic datasets includes developing a weighted average of first least-squares filters assuming the data from the first dataset is the input and the data from the second dataset is the desired output, developing a weighted average of second least-squares filters assuming the data from the second dataset is the input and the data from the first dataset is the desired output, determining a first transfer function from the first weighted average filter design and a second transfer function from the second weighted average filter design, plotting respective amplitude and phase spectra using each of the first and second transfer functions, plotting the product of the amplitude spectra and the sum of the phase spectra and determining the common bandwidth where the amplitude spectra is one and the phase spectra is zero.

Abstract: The present invention provides a method of seismic exploration for obtaining a measure of the subterranean formation rock properties. Incident angle ordered gathers of seismic signal are processed to obtain a measure of the reflection coefficient as well as attributes descriptive of variations in amplitude of the seismic signal as a function of incident angle. Such attributes, when plotted on an angle dependent amplitude diagram, are transformed into a most probable estimate of the subterranean formation rock properties as well as a diagnostic of relative lithology and pore fluid contrast.