Abstract: A method for visualizing seismic data of a subterranean formation, including obtaining an estimated dip field of the subterranean formation, wherein the estimated dip field represents a measure of deviation of a stratigraphic layer from flat, extracting a matrix data item surrounding a voxel of the seismic data, wherein the matrix data item is extracted from the seismic data based on a value of the estimated dip field surrounding the voxel, generating modified seismic data by at least applying a matrix operator to the seismic data, wherein the matrix operator calculates a partial derivative of the seismic data using the matrix data item, and displaying the modified seismic data.

Abstract: A system and method for locating subsurface diffractors. The method operates on two-dimensional (2-D) seismic data that includes one or more 2-D seismic lines. The 2-D seismic data may be preprocessed to enhance diffracted energy. For each hypothetical diffractor location in a set of hypothetical diffractor locations, the method involves analyzing at least a subset of the seismic traces of the one or more 2-D seismic lines, in order to compute a value indicating an extent to which those seismic traces contain diffraction arrivals consistent with the hypothetical diffractor location. The method may further involve generating, storing and displaying an image (or map) based on the computed values. The image may illustrate areas of high, intermediate and low diffraction, and may be used to assess the formation.

Abstract: A technique for performing a fast residual migration of seismic data through parsimonious image decomposition is presented. In one aspect, the technique includes a software-implemented method for processing a set of seismic data includes through parsimonious image decomposition. Other aspects of the technique include a program storage medium encoded with instructions that, when executed by a processor, perform such a method or a computing apparatus programmed to perform such a method.

Abstract: Embodiments of various technologies for a method for processing seismic data are disclosed. In one embodiment, a first portion of a record of pre-stack seismic data may be displayed in a three-dimensional XYZ (3-D XYZ) space. A selection may be received of a second portion of the record of the pre-stack seismic data within the first portion. One or more attributes may be determined that define the second portion. One or more regions may be identified within the record of the pre-stack seismic data having the attributes that define the second portion.

Abstract: A technique includes processing first data indicative of a first image of a subsurface region of interest on a machine to generate second data indicative of a second image. The first image is derived from measurements of seismic waves, which propagate in a plurality of directions, and the second image is generated by partitioning the first image based on the directions. The technique includes processing the second data to determine a dip decomposition for each of the directions; and based on the dip decompositions and the directions, generating an angle domain common image gather.

Abstract: A technique includes receiving first seismic data acquired by one or more receivers in response to energy produced by one or more seismic sources interacting with a subsurface feature. The first seismic data is indicative of measured reflection coefficients for image points for the subsurface feature, the measured reflection coefficients are associated with incidence angles, and a range of the incidence angles varies with respect to an image point position. The technique includes processing the first seismic data in a machine to generate second data indicative of a normal incidence reflection coefficient for at least one of the image points not associated with a normal angle of incidence.

Abstract: A geophysical model of a subsurface region is generated based on seismic data, e.g., seismic reflection data. Migration and seismic inversion are applied to the seismic data to generate estimates of one or more physical or seismic properties of the subsurface region. Seismic inversion, such as spectral shaping inversion, is applied before or after migrating the seismic data through a variety of techniques that each avoid the amplification of dipping energy while optimizing computational efficiency and/or accuracy.

Abstract: A method for structural dip removal. The method includes converting a seismic volume to a depth domain, extracting seismic dips from the seismic volume in the depth domain along a borehole trajectory, analyzing a borehole using the seismic dips to obtain structural dip data, and in response to determining that the seismic dips and borehole dips obtained from borehole imagery are consistent, generating a three dimensional (“3D”) structural model using the structural dip data. The method further includes performing a structural restoration using the 3D structural model to obtain depositional geometry data, removing structural dip from the borehole imagery using the 3D structural model to obtain sedimentary dip data, and performing a stratigraphic interpretation using the depositional geometry data and the sedimentary dip data.

Abstract: Systems, program product, and methods of suppressing residual water bottom energy in seismic data, are provided. An example of a system, program product, and method can be applied to post-stack datasets and can combine multi-channel deconvolution with novel sorting keys to efficiently identify and suppress residual water bottom energy in common depth point (CDP) stacked seismic data, thereby increasing the resolving power of seismic data leading to an improved interpretation of seismic signals reflected from oil reservoirs.

Abstract: A method for predicting a plurality of surface multiples for a plurality of target traces in a record of seismic data acquired in a survey area. The method includes selecting a target trace and identifying two or more desired traces for multiple prediction based on the target trace. After identifying the desired traces, the method identifies one or more recorded traces for each desired trace. Each identified recorded trace is described as being substantially close to one of the desired traces. The method then includes correcting the identified recorded traces for one or more geometry-related effects associated with the survey area and convolving the corrected recorded traces to generate a plurality of convolutions. After convolving the corrected recorded traces, the method then stacks the convolutions.

Abstract: A system and method for locating subsurface diffractors. The method operates on two-dimensional (2-D) seismic data that includes one or more 2-D seismic lines. The 2-D seismic data may be preprocessed to enhance diffracted energy. For each hypothetical diffractor location in a set of hypothetical diffractor locations, the method involves analyzing at least a subset of the seismic traces of the one or more 2-D seismic lines, in order to compute a value indicating an extent to which those seismic traces contain diffraction arrivals consistent with the hypothetical diffractor location. The method may further involve generating, storing and displaying an image (or map) based on the computed values. The image may illustrate areas of high, intermediate and low diffraction, and may be used to assess the formation.

Abstract: Methods of and apparatus to image one or more subsurface formation features are disclosed. An example method includes generating acoustic waves with a transmitter and receiving the acoustic waves and acoustic data contained therein at one or more receivers. The example method also includes extracting one or more S-S, P-S or S-P reflected waveform data from the acoustic data, estimating a dip of the one or more subsurface formation features, migrating the one or more S-S, P-S or S-P reflected waveform data with the estimated dip and mapping the migrated one or more S-S, P-S or S-P reflected waveform data. In addition, the example method includes identifying one or more permeable subsurface formation features using the mapped migrated one or more S-S, P-S or S-P reflected waveform data.

Abstract: Methods, systems, and software for representing seismic shot or receiver data as a superposition of a plurality of diplets are disclosed. The method includes decomposing one or more prestack shot or receiver records into a set of diplets, migrating the diplets using one or more velocity models, and synthesizing one or more migrated diplets into a migrated seismic volume, wherein each diplet comprises information about spatial location, orientation, amplitude, an associated wavelet, acquisition configuration, and coherency.

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 performed (i) corrects for misalignment of the one or more source locations and/or the one or more detector locations with a regular, predetermined mesh, and (ii) steers the seismic data based on the modeled beams.

Abstract: In at least some embodiments, the system obtains shot gathers for a survey region and migrates the shot gather data with an initial velocity model to obtain angle-domain common image gathers. The system processes the common image gathers to determine depth residuals and corresponding angle-dependent time deviations throughout a seismic survey region. The system solves a set of tomographic equations which employ ray theory to establish a relationship between a travel time deviation and the depth residual of a reflector in the depth-offset ray parameter (z,p) domain. The resulting updates are applied to the velocity model and can be used to re-migrate the shot gather data. The system generates a representation of the survey region that can be displayed to a user.

Abstract: A method to correct errors in a conversion from time gather to angle gather using slant stacks wherein the slant stacking is performed along a direction that is normal to a dip or along three orthogonal directions. The slant stacking is performed in various domains.

Abstract: A computer-implemented method for pseudo acoustic quasi-P wave propagation which remain stable in anisotropic media with variable tilt and is not limited to weak anisotropic conditions. The method includes acquiring a seismic exploration volume for a subsurface region of interest, and determining a modeling geometry for the seismic exploration volume. The method further includes propagating at least one wavefield through the seismic exploration volume utilizing the modeling geometry and initial conditions and preventing the accumulation of energy along the axis of symmetry of the seismic exploration volume and ensuring positive stiffness coefficients in the stress-strain relations through the use of finite quasi-S wave velocities thereby producing a stable wavefield. The method includes utilizing the stable wavefield to generate subsurface images of the subsurface region of interest.

Abstract: Method for transforming geologic data relating to a subsurface region between a geophysical depth domain and a geologic age domain. A set of topologically consistent surfaces (252a) is obtained that correspond to seismic data (252). The surfaces are enumerated in the depth domain. An age is assigned to each surface in the depth domain (255). The age corresponds to an estimated time of deposition of the respective surface. An age mapping volume is generated (256). An extent of the age domain is chosen. A depth mapping volume is generated (260). Both the age mapping volume and the depth mapping volume are used to transform geophysical, geologic, or engineering data or interpretations (258, 263) between the depth domain and the age domain (268) and vice versa (269). The geophysical, geologic, or engineering data or interpretations transformed by at least one of the age or depth mapping volume are outputted.

Abstract: Dips are calculated for a series of sets of adjacent multiple contribution traces, from seismic data representative of subsurface formations, in the vicinity of a boundary of an aperture of a multiple contribution gather, the seismic data acquired by deploying a plurality of seismic sensors proximate an area of the earth's subsurface to be evaluated, the seismic sensors generating at least one of an electrical and optical signal in response to seismic energy. The boundary of the aperture of the multiple contribution gather is recursively extended, based on the calculated dips. Multiple contribution traces in the multiple contribution gather with the extended aperture boundary are stacked to generate predicted multiple traces. The predicted multiple traces are subtracted from the seismic data to generate surface-related multiple attenuated data useful for imaging the subsurface formations.

Abstract: A method of imaging a target area of the subsoil from “walkaway” data having application to development of oil reservoirs or monitoring of geologic storage sites is disclosed. After acquisition of seismic data of walkaway type and estimation of the rate of propagation of the seismic waves in the subsoil, p illumination angles are selected. The seismic measurements are then converted to data Dp by illumination angle. The distribution of acoustic impedances best explaining data Dp is determined within the target by using a non-linear inversion which minimizes a difference between the data Dp obtained from measurements and data by illumination angle resulting from an estimation. This estimation is performed by solving a wave propagation equation from the velocity field, an acoustic impedance distribution and a pressure distribution at the level of the top of the target for each illumination angle.

Abstract: A method of transforming geologic data relating to a subsurface region between a geophysical depth domain and a geologic age domain is disclosed. A set of topologically consistent surfaces is obtained that correspond to seismic data. The surfaces are enumerated in the depth domain. An age is assigned to each surface in the depth domain. The age corresponds to an estimated time of deposition of the respective surface. An age mapping volume is generated. An extent of the age domain is chosen. A depth mapping volume is generated. Both the age mapping volume and the depth mapping volume are used to transform geophysical, geologic, or engineering data or interpretations between the depth domain and the age domain and vice versa. The geophysical, geologic, or engineering data or interpretations transformed by at least one of the age mapping volume and the depth mapping volume are outputted.

Abstract: Time slices of seismic data are transformed from rectangular space-time domain to cylindrical space-time domain. 2-D seismic migration is performed on the transformed data for each radial direction. Slices of the migrated data are inverse transformed back to the rectangular space-time domain, generated migrated 3-D data for generally inhomogeneous media.

Abstract: A method for migrating three dimensional seismic data in tilted transversely isotropic media (“TTI”) is based on generating numerical solutions to an exact relationship for a three dimensional dispersion relationship of seismic energy traveling through TTI media. The numerical solutions use selected input values of polar angle and azimuth angle of a transverse isotropic axis of symmetry, and selected values of Thomsen anisotropic parameters to generate tables of numerical values. Based on the tables of numerical values, optimized coefficients for a finite-difference relationship are estimated along multiple splitting directions. The seismic data are then migrated using a three dimensional Fourier finite difference extrapolation algorithm.

Abstract: The invention discloses a way to recover separated seismograms with reduced interference noise by processing vibroseis data recorded (or computer simulated) with multiple vibrators shaking simultaneously or nearly simultaneously (200). A preliminary estimate of the separated seismograms is used to obtain improved seismograms (201). The preliminary estimate is convolved with the vibrator signature and then used to update the seismogram. Primary criteria for performing the update include fitting the field data and satisfying typical criteria of noise-free seismograms (202). Alternative ways to update are disclosed, including signal extraction, modeled noise extraction, constrained optimization based separation, and penalized least-squares based separation. The method is particularly suited for removing noise caused by separating the combined record into separate records for each vibrator, and is advantageous where the number of sweeps is fewer than the number of vibrators (200).

Abstract: A method of prestack reverse-time migration of seismic data that yields significant gains in computer storage and memory bandwidth efficiency is disclosed. The values only of the source wave incident on the boundaries of a simulation domain are saved, rather than all of the values of the wavefield throughout the entire simulation domain. This data allows an accurate and robust approximation of the forward propagated source wave for all finite-difference approximation orders of the acoustic wave equation. The method reduces the amount of data storage required by an order of magnitude and overcomes the present challenge of requiring special large memory hardware while allowing for the implementation of 3D prestack reverse-time migration on off-the-shelf platforms.

Abstract: Methods and apparatuses are disclosed for replacing the individual receivers used with a seismic interferometry process with an array of seismic receivers and then manipulating the array data in order to measure and modify the typical non-uniform directionality function of the background seismic energy. The non-uniform directionality function is a significant cause of noise with seismic interferometry. Furthermore, the array of receivers may be used to significantly enhance the preferred reflection energy and damp undesirable near surface energy. The directionality function may be modified by using an array of receivers for the virtual source location of seismic interferometry to measure the non-uniform directionality function, generating multiplication factors, and applying the multiplication factors to convert the measured directionality function into a desired directionality function.

Abstract: Computer-based method and system are disclosed for interpreting dips, dip trends, and mineral based lithofacies data to identify certain geological events in a subsurface formation. The disclosed method/system analyzes dip magnitude and azimuth data to determine the dip trends in the formation. The dip trends are then examined for indications of the presence of certain depositional events, such as build-ups, flow directions instances of scour and fill, direction to thalweg, parallel bedding, indications of fault, and the like. If lithofacies data is available the disclosed method/system can also analyze this data to identify the presence of interbedded sequences and condensed sections. Such an integrated solution saves geoscientists and interpreters an enormous amount of time compared to existing interpretation techniques, allowing them to be much more productive. The disclosed system/method may also be used to help train new and less experienced geoscientists and interpreters.

Abstract: A method is disclosed that uses (a) source-receiver reciprocity and (b) a method such as ISR DMO (U.S. Patent Application Publication No. 2006/0098529) that allows reconstruction of densely sampled gathers at arbitrary surface locations, to efficiently predict multiple reflections, either surface related or interbed multiples, in seismic data. For each reconstructed gather and each output (field) trace, two traces are extracted corresponding to the field source and receiver positions of the output trace, then they are convolved and the convolution result is added (summed) to that obtained by applying this procedure to previously reconstructed gathers. The efficiency results from the fact that the convolutions are performed by looping over all traces for each “bounce” point, with the outer loop being over bounce points. Once all the reconstructed gathers are processed, multiple predictions are obtained for the whole survey by conventional means.

Abstract: A method of performing migration velocity analysis may include: obtaining seismic data and an initial velocity model; determining reflection points; deriving a wavepath backprojection operator based on the initial velocity model and the reflection points by constructing wavepaths from each reflection point of the reflection points; and performing a traveltime inversion using the wavepath backprojection operator. The initial velocity model may be updated based on the traveltime inversion. Determining reflection points may be automated by calculating reflection points based on results from a depth migration algorithm performed on the initial velocity model. Selection of residual moveout values may be automated by selecting based on a dip field for each prestack gather obtained from a depth migration algorithm performed on the initial velocity model. Residual traveltimes may be calculated using the selected residual moveout values. The residual traveltimes may be used in the traveltime inversion.

Abstract: A method of conducting a seismic survey of an area including a region of high seismic velocity regimes in a shallow overburden. According to the method, a zone is identified in which the boundary of the high seismic velocity region has a substantially constant critical angle and a course is plotted through the identified zone. A zone based directional seismic source is applied sequentially, with a directivity angle equal to or close to the measured critical angle. The response is detected using receivers.

Abstract: A method for analyzing seismic data from a formation. The method may first receive two-dimensional (2-D) seismic data of a formation comprising a number of individual seismic lines acquired over an exploration area and having a large interline spacing. The 2-D seismic data may then be preprocessed to enhance diffracted energy. For each respective hypothetical diffractor location, the method may then search for coherent diffraction arrivals on nearby 2-D seismic lines consistent with the respective hypothetical diffractor location. The method may then store information regarding identified diffractor locations. The method may then create a map based on the identified diffractor locations, wherein the map illustrates areas of high diffraction. The map may then be displayed on a display, wherein the map is useable to assess the formation.

Abstract: A method and apparatus for predicting a plurality of surface multiples for a plurality of traces in a record of seismic data. In one embodiment, the method includes providing a plurality of target traces at a nominal offset and a nominal azimuth; selecting a plurality of pairs of input traces, wherein the midpoints of the input traces in each pair are separated by half the nominal offset and the azimuth of a line connecting the midpoints of the input traces in each pair is equal to the nominal azimuth; convolving the selected pairs of input traces to generate a plurality of convolutions; and applying a three dimensional operator to the convolutions.

Abstract: Method for interpolating aliased seismic data to generate shot records at regular shot points. The method involves sorting the data into common offsets to obtain the finer sampling in the common-offset domain, then using DMO to transform the data to zero offset to eliminate azimuth and offset variations, from which densely sampled shot records are reconstructed by an efficient Log-Stretch Inverse Shot Record DMO. The method has ready application to techniques that benefit from input data that are regularly and densely sampled, such as 3-D surface related multiple elimination and shot record wave equation migration.

Abstract: The invention relates to a method of seismic data processing, wherein the data includes a set of seismic traces, with each trace including a signal that has been recorded by a sensor after having been propagated in a subsurface area, with the signal being defined by an amplitude as a function of time, including the steps of: migration of data according to an initial time-velocity model, picking in the time-migrated data one or more event(s) corresponding to one or more subsurface reflector(s) so as to obtain facets locally approximating the event, kinematic demigration of the facets plotted so as to obtain simplified seismic data in the form of a set of facets and a set of attributes associated with the facets.

Abstract: The invention is a method for defining the development conditions of a hydrocarbon reservoir by updating a velocity model by means of log data. A first seismic depth image representative of the reservoir is established by using seismic data and a velocity model. A series of log data is acquired from wells. Differences between seismic reflector depths observed in the first seismic depth image and depths for these reflectors identified in the wells are measured. The velocity model is modified to minimize these errors, using a prestack kinematic inversion technique allowing constraints to be taken into account. A new seismic depth image from which the development conditions of the hydrocarbon reservoir are determined is deduced therefrom. The invention has application for hydrocarbon reservoir development.

Abstract: A method and system for seismic data processing utilizes azimuthal variations in the velocity of seismic signals. The system and method utilizes a plurality of seismic energy sources that are located at known positions at the surface of the earth. The seismic energy sources generate seismic signals that propagate downward into the earth. Some of the seismic signals are reflected and diffracted by various sub-surface layers and are returned to the surface of the earth. The returned seismic signals are received by a plurality of receivers. The method includes the step of determining the distance from an energy source to an image point. A fast travel time of the seismic signal from the energy source to the image point is determined, and a slow travel time of the seismic signal from the energy source to the image point is determined. The azimuth angle between the energy source and the surface location of the image point is calculated.

Abstract: A method of imaging in an underground formation one or more steep-sloping geologic interfaces, which are not necessarily in a plane, by forming with primary reflectors, which are not necessarily in a plane, dihedra giving rise to prismatic seismic reflections (double reflections). The geometry of the steep-sloping interface is determined from choosing seismic records of one or more events corresponding to prismatic reflections for different source-pickup pairs of an acquisition device. A new reflection tomography technique is used, wherein introduction of specific constraints guarantees the convergence of the algorithm. The velocity distribution in the geologic formation and/or the geometry of the interface(s) between the sedimentary layers can be known otherwise or determined by means of the method. The method can apply to a formation comprising several different sloping interfaces.

Abstract: A system and method using inverse-vector processing to iterate through a loop of three steps: set a guide direction, invert opposite vectors, and average vectors to update the guide direction, for smoothing seismic amplitude data. The inverse-vector method can overcome instabilities where the traditional structure-tensor approach fails. The inverse-vector smoothing is simple to implement and more computational efficient. The resultant dips and azimuths are spatially consistent and thus more interpretable and suitable for calculation of curvature and other dip based attributes.

Abstract: A one-return wave equation migration is used to extrapolate both down-going and up-going waves. Followed by a properly designed imaging condition, the partial image contributed form turning waves is correctly reconstructed. Numerical examples show that this method can significantly enhance definition of an overhanging salt boundary and a geological structure with vertical features.

Abstract: A method is disclosed for depth migrating seismic data. The method includes pre-stack time migrating the seismic data to form a stacked, time migrated image. The stacked, time migrated image is demigrated, and post-stack depth migration is then performed on the demigrated image. In some embodiments, the pre-stack time migration and the demigration account for ray bending in vertically transversely isotropic media.

Abstract: System and method for performing anisotropy corrections of post-imaging seismic data for a subsurface formation. The method may receive seismic data, preferably pre-stack seismic data comprising a plurality of traces, e.g., collected from a plurality of source and receiver locations. The seismic data may be imaged/migrated to produce imaged seismic data, which is organized into an arrangement that preserves aspects of the relative seismic propagation angle in the subsurface. One or more anisotropic parameters and corresponding corrections may be determined by analyzing the organized imaged seismic data. The determined parameters or corrections may be used to correct at least a subset of the imaged seismic data, thereby producing corrected seismic data which is useable in analyzing the formation. The corrected data may then optionally be stacked to produce a collection of corrected stacked traces, and/or analyzed as desired. The pre-stack data and/or the corrected seismic data may optionally be displayed.

Abstract: Method of determining the specular source/receiver pairs associated with seismic images produced from a transformation of multi-offset seismic wave records as a function of time in the depth domain. When using a prestack depth migration algorithm of Kirchhoff type, one also calculates and saves, in addition to the necessary traveltimes of the rays from the sources and receivers of the acquisition device to the image points of the image to be migrated, the line parameters of these rays and the desired quantities to be reached in fine. Then, once the prestack migrated volume produced, the local slopes of seismic events of interest for the image points considered are extracted. Comparison between line parameters saved during migration and the normal to the local slopes at the image points considered shows which ray is specular among those for which information has been saved, and allows to produce then the required quantity, which is then referred to as specular quantity.

Abstract: A method for interpreting seismic data below a salt layer includes depth migrating the seismic data to a bottom of the salt layer. The migrating including generating an initial model of velocities below the salt layer. The initial model is scaled by a plurality of scale factors at at least one image position. At least one of the plurality of scale factors for which a depth migrated image below the salt layer is optimum is selected as the scale factor.

Abstract: A Method for Interpreting Seismic Data Using Duplex Waves is described. Whereas substantially horizontal boundaries are readily identified using conventional processing methods based on primary reflections, it has been difficult or impossible to use such methods for locating substantially vertical events or boundaries. The method of the present invention uses secondary reflections to locate substantially vertical events by gathering common source or receiver traces for processing. Wave fields of these gathers are continued downward to the level of the base boundary, then at each discrete depth level, a seismic image of sub-vertical events is formed. The downward-continued gathers correspond to the travel time of the wave from when it left the source or the receiver point, was reflected from the base boundary, and arrived to the corresponding point of the discrete level of wave-field continuation.

Abstract: A method of generating a semblance panel comprises summing two or more gathers of traces. The dip of the reflector is taken into account in the summation process, and this prevents semblance peaks from becoming smeared during the summation process and so allows a greater number of gathers to be used to generate the semblance panel. In an embodiment of the invention the dip is determined from the seismic data. Alternatively, the reflector dip used in the summation process may be obtained from pre-existing data acquired at the survey location, or the reflector dip may be already known. The invention can be applied to seismic data containing events from more than one reflector.

Abstract: A method and apparatus for compensating acquired seismic data for the presence of dipping events are disclosed. The method includes migrating the acquired, unstacked seismic data; and spatially mapping the migrated seismic data to correct their respective offsets while maintaining the angle of incidence to a dipping event. The method may be performed by a programmed computing device or encoded as instructions for a computing device on a program storage medium.

Abstract: A method of generating a semblance panel comprises summing two or more gathers of traces. The dip of the reflector is taken into account in the summation process, and this prevents semblance peaks from becoming smeared during the summation process and so allows a greater number of gathers to be used to generate the semblance panel. In an embodiment of the invention the dip is determined from the seismic data. Alternatively, the reflector dip used in the summation process may be obtained from pre-existing data acquired at the survey location, or the reflector dip may be already known. The invention can be applied to seismic data containing events from more than one reflector.

Abstract: A method and apparatus for compensating acquired seismic data for the presence of dipping events are disclosed. The method includes migrating the acquired, unstacked seismic data; and spatially mapping the migrated seismic data to correct their respective offsets while maintaining the angle of incidence to a dipping event. The method may be performed by a programmed computing device or encoded as instructions for a computing device on a program storage medium.

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: Method and systems are provided for processing c-wave data resulting in less sensitivity to errors in p-wave velocity analysis. Therefore, according to one aspect of the invention, a process is provided for processing c-wave data, the process comprising: providing zero-offset gather without a hyperbolic movement correction; performing migration on the zero-offset gather; performing velocity analysis on the migrated zero-offset gather; and performing NMO on the migrated data using the velocity from the velocity analysis.