Abstract: The disclosure describes a method and apparatus for effectively communicating data along an acoustic transmission path. The method comprises driving an acoustic transmitter to send a data signal along the acoustic transmission path, where the signal is distorted by ambient noise. The distorted signal is input to a spaced apart plurality of sensors so that consequent time-delayed signals provide reinforcement of the basic signal and attenuation of the ambient noise component when combined.

Abstract: A method for collecting data for a geographic database is disclosed. Speed and position data are collected using a plurality of mobile computing platforms moving in a geographic region. The speed and position data are analyzed to identify a location of a recurring delay point corresponding to a change in the speed. The geographic database is updated to indicate the location of the recurring delay point.

Abstract: Neural networks may be used to determine and predict formation dip angles and perform quality assurance assessments from data collected with a multi-component induction tool used for well logging. The neural networks make use of corrected, rotated and normalized data to provide the predictions and assessments. Synthetic data using various models is used to train the neural networks. The teachings herein provide for real-time determinations with a substantial degree of accuracy in the results.

Abstract: The technologies described herein include systems and methods for encoding/decoding seismic sources and responses, generating and using of source-side derivatives while also generating and using the conventional source response. Sources in an array may be encoded such that activation of each source in the array constitutes a single spike in a sequence orthogonal to another sequence emitted by another source. The responses to these different sources that are in close spatial proximity can be decoded and separated. Source-side derivatives may be calculated and utilized in various applications in combination with the monopole response from the source location, including source-side deghosting, spatial (horizontal and vertical) interpolation and imaging.

Abstract: Implementations of various technologies for processing seismic data. In one implementation, the seismic data may be processed by creating a fictitious source-receiver line connecting a source with a receiver location of interest, projecting one or more receiver locations adjacent the receiver location of interest onto the fictitious source-receiver line and decomposing seismic data on the receiver locations disposed on the fictitious source-receiver line into up-going wavefields and down-going wavefields.

Abstract: A Laplace transform system comprising a processor, a measured time domain wavefield, a velocity model, and Laplace damping constants, wherein the processor is programmed to calculate a substantially about zero frequency component of a Fourier transform of a time domain damped wavefield, wherein the time domain damped wavefield is damped by the Laplace damping constants to obtain long wavelength velocity information for deeper subsurface regions.

Abstract: Methods of processing seismic data to remove unwanted noise from meaningful reflection signals are provided for. The methods comprise the steps of assembling seismic data into common geometry gathers in an offset-time domain without correcting the data for normal moveout. The amplitude data are then transformed from the offset-time domain to the time-slowness domain using a limited Radon transformation. That is, the Radon transformation is applied within defined slowness limits pmin and pmax, where pmin is a predetermined minimum slowness and pmax is a predetermined maximum slowness. A corrective filter is then applied to the transformed data enhance the primary reflection signal content of the data and to eliminate unwanted noise events. After filtering, the enhanced signal content is inverse transformed from the time-slowness domain back to the offset-time domain using an inverse Radon transformation.

Abstract: Method for correcting seismograms to compensate for absorption effects that occur in the earth. In one implementation, the method may include computing a ratio of traveltime to absorption parameter for each seismogram to generate a system of linear equations. The ratio is expressed as a linear equation having a plurality of components. The method may further include solving the system of linear equations for the plurality of components, adding one or more of the solved components to generate an estimate of the ratio of traveltime to absorption parameter, and correcting the seismograms using the estimate of the ratio of traveltime to absorption parameter.

Abstract: The present invention incorporates the use of model-driven and data-driven methodologies to attenuate multiples in seismic data utilizing a prediction model which includes multiply-reflected, surface-related seismic waves. The present invention includes beam techniques and convolving a predicted multiples beam with a segment of a modeled pegleg beam to obtain a convolved multiples beam. The convolved multiples beam can then he deconvolved to attenuate the multiples that are present in the original input beam.

Abstract: A method of acquiring or processing multi-component seismic data obtained from seismic signals propagating in a medium, the method comprising the steps of: selecting a first portion of the seismic data in which the first arrival contains only upwardly propagating seismic energy above the seafloor; and determining a first calibration filter from the first portion of the seismic data, the first calibration filter being to calibrate a first component of the seismic data relative to a second component of the seismic data.

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 technique includes obtaining a noise measurement, which is acquired by a seismic sensor while in tow. Based on the noise measurement, a compensation for at least one of an alignment of the sensor and a calibration of the sensor is determined.

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: Coherent wave noise energy is removed from seismic data by modeling both the P-wave primary energy and the coherent wave noise energy. The P-wave primary energy is modeled first and then subtracted from the input data. The data with the P-wave primary energy removed is used as the input for coherent wave energy removal. The coherent wave energy is modeled and subtracted from the original input data, i.e. the data input into P-wave primary removal. This leaves a dataset with P-wave primary energy and noise energy not related to coherent waves. This method can be utilized to remove all types of coherent noise with a velocity difference to the desired P-wave primary energy or with a different type of moveout (change of time of arrival with source-receiver distance) such as, for example, linear moveout.

Abstract: The present invention provides a method and apparatus for seismic data acquisition. One embodiment of the method includes accessing data acquired by at least two particle motion sensors. The data includes a seismic signal and a noise signal and the at least two particle motion sensors being separated by a length determined based on a noise coherence length. The method may also include processing the accessed data to remove a portion of the noise signal.

Abstract: Methods and apparatus for processing dual sensor (e.g., hydrophone and vertical geophone) data that includes intrinsic removal of noise as well as enhancing the wavefield separation are provided. The methods disclosed herein are based on a decomposition of data simultaneously into dip and frequency while retaining temporal locality. The noise removed may be mainly coherent geophone noise from the vertical geophone, also known as V(z) noise.

Abstract: A process for constructing a three-dimensional geologic model of a subsurface earth volume wherein resolution scales of multiple diverse data types, including seismic data, are accounted for by generating multiple frequency passband models and combining them together to form the complete geologic model. Preferably, a model is generated for each of a low-frequency passband, a mid-frequency passband, and a high-frequency passband. When integrating seismic data into the modeling process, the seismic-frequency passband constitutes the mid-frequency passband model. The process further contemplates updating tentative frequency-passband models through optimization of assigned rock property values in each tentative model according to specified geological criteria. Such optimization is carried out by perturbation of the rock property values in a manner wherein the frequency content of each model is maintained.

Abstract: This invention relates to a method for processing seismic data comprising a collection of seismic traces with different offsets, comprising the steps of: a) breaking up one or several first trace(s) of the collection of seismic traces into a series of trace segments according to a predetermined segmentation interval; b) defining a series of expansion coefficients, each expansion coefficient being associated with a segment of the first trace or traces; c) applying the associated expansion coefficient to each segment of the first trace or traces; d) comparing the first trace or traces thus expanded with a second trace from the collection of seismic. traces to evaluate their similarity; e) repeating steps b), c) and d) with a new series of expansion coefficients, f) determining an optimum series of expansion coefficients that maximizes the similarity between the first expanded trace and the second trace in order to obtain one or several corrected first trace(s).

Abstract: A method for filtering noise from seismic data is disclosed. The method includes: receiving at least one seismic data set; computing a value of at least one subset of a plurality of subsets of the at least one seismic data set; computing quartiles and an upper moustache (M) for the plurality of subsets; comparing the upper moustache (M) to the value of the at least one subset; and one of discarding and retaining the at least one subset as filtered seismic data. A system and computer program product for filtering noise from seismic data is also disclosed.

Abstract: A method and apparatus for filtering data acquired at a plurality of discrete data points is described, using the steps of defining a filter having defined filter values at defined filter points at least partially not coincident with the data points and using the defined filter values at the defined filter points to determine filter values at the data points, thereby correcting the filter to have filter values at filter points coinciding with the data points and filtering the data using the corrected filter.

Abstract: The invention relates to processing seismic data that contains both a desired signal and swell noise. The method is applicable to seismic data is in the frequency-space domain method and comprises determining a signal-only prediction filter from the seismic data at a first frequency at which swell noise is not present, and applying the prediction filter to seismic data at a second frequency at which swell noise is present. This attenuates swell noise in the seismic data at the second frequency. In one embodiment, the prediction filter for a frequency fL, the lowest frequency at which swell noise is present, is determined from seismic data at frequency fH+1, where fH is the highest frequency at which swell noise is present. The prediction filter for a frequency fL+1 is determined from seismic data at frequency fH+2, and so on, so that the prediction filter for frequency fH+1 is determined from seismic data at frequency f2H?L+1.

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: Method for controlling the phase spectrum of seismic data to match assumptions inherent in subsequent processing steps. The source signature, after processing with the same initial processing steps used on the data, is used to design a phase control filter that shapes the seismic data to have a minimum phase spectrum or whatever other phase spectrum the subsequent processing algorithms may assume. The processed data is then filtered with a second phase-control filter, also designed using the parallel-processed signature, to shape the data to zero phase or whatever other phase may be desired for interpretation of the data.

Abstract: The present invention includes a method for determining interval values of seismic quality factor, Q, from seismic data. Seismic data is recorded and preprocessed as necessary. Estimates of amplitude spectra are determined from the seismic data. Logarithms are taken of the amplitude spectra and weights derived from the amplitude spectra. Interval values of seismic quality factor, Q, are determined by performing a weighted fit to the log-amplitude spectra with a function that is parameterized by an initial wavelet, an attenuation profile (1/Q) and an absolute-scaling profile.

Abstract: A method, comprising: generating a macro P-wave velocity model, including resolution of residual moveout errors, using reflection tomography from a seismic data set; generating a diffraction response from the macro P-wave velocity model for a given common image gather location therein assuming a locally laterally invariant model; converting the generated diffraction response for the given common image gather location to a migrated reflection response to yield a modeled data set; comparing the modeled data set to the given common image point from the seismic data set; updating the macro P-wave velocity model based on the result of the comparison; and iterating the diffraction response generation, the diffraction response conversion, comparison, and update until the modeled data set converges to the common image gathers.

Abstract: The invention relates to a method of processing seismic data comprising a gather of seismic traces organised according to one or several acquisition parameters, each trace comprising a seismic signal defined by an amplitude as a function of time or depth, the method comprising the steps of: a) defining a base of elementary functions of the acquisition parameter(s), b) orthogonalising said elementary functions so as to define a base of orthogonal elementary functions c) for a given time or at a given depth, determining combination coefficients defining a combination of the orthogonal elementary functions, said combination being an estimator of a variation in the amplitude of the seismic signal as a function of the acquisition parameter(s).

Abstract: Methods of processing seismic data to remove unwanted noise from meaningful reflection signals are provided for. The methods comprise the steps of assembling seismic data into common geometry gathers in an offset-time domain without correcting the data for normal moveout. The amplitude data are then transformed from the offset-time domain to the time-slowness domain using a Radon transformation. A corrective filter is then applied to enhance the primary reflection signal content of the data and to eliminate unwanted noise events. The corrective filter has a pass region with a lower pass limit and a higher pass limit. The higher pass limit is set within 15% above the slowness of the primary reflection signals and, preferably, it is more closely set to the slowness of the primary reflection signals. The lower pass limit is also preferably set within 15% below the slowness of the primary reflection signals.

Abstract: A method for determining impedance coefficients of a seismic trace comprises determining reflection coefficients of the seismic trace, for example using a sparse spike inversion, integrating the reflection coefficients with respect to time to obtain impedance coefficients, and filtering the impedance coefficients by applying a low-cut window filter. The window size and/or shape may be defined by a variable parameter which may be either specified by a user or optimised on the basis of a lateral variability parameter calculated for different values of the window parameter.

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: A subterranean structure is characterized using composite seismic response data received from a plurality of sources. Phase encoding is applied to the data in which phase shifts are selected based on frequency variation of noise terms. The phase-encoded data is then migrated and a representation of the subterranean structure is produced according to the migrating.

Abstract: Method of processing a collection of seismic cubes corresponding to one and the same acquisition zone and to various moments of acquisition, characterized in that at least one seismic cube which is an estimate of the component common to at least two seismic cubes corresponding to different moments of acquisition is determined and this estimate of common component is subtracted from at least one of the two initial cubes.

Abstract: A method is disclosed for reconstructing complex wave attributes from limited view measurements of a scattering object. The method involves the analytic continuation of the Fourier transform of the object function into the area in which there is an absence of K-space coverage by requiring objects to be an even function. (It is assumed that physical objects are even functions, and it is this assumption that allows analytic continuation.) When the object function is not centered at the origin, the measurements are shifted to the origin prior to determining the analytic continuation and returned to their original location following analytic continuation.

Abstract: An iterative process is described for obtaining a finite impulse filter to remove noise from seismic data through an iterative process with constraints on the filter applied in both, the original space-time and the transform frequency wave number at each iteration step.

Abstract: This invention relates in general to vibroseis and, more specifically, but not by way of limitation, to the enhancement and/or signal strength optimization of low frequency content of seismic signals for use in surveying boreholes and/or subsurface earth formations. In embodiments of the present invention, physical properties of a seismic vibrator may be analyzed and used to provide for determination of a driving force necessary to drive a reaction mass to produce a sweep signal with enhanced low frequency content for injection into the ground for vibroseis. In certain aspects, the physical properties may be considered independent of any geophysical properties related to operation of the seismic vibrator.

Abstract: A method of processing multi-component seismic data acquired at a receiver station comprises determining a calibration filter that calibrate a first component of the seismic data relative to a second component of the seismic data in order to compensate for differences in coupling between the two components. The determination of the calibration filter comprises processing the data in the common shot domain. This allows optimisation criteria to be applied to the up- and down-going constituents of particle velocity, and this is simpler than prior art methods of applying optimisation criteria to the up-going and down-going constituents of the pressure.

Abstract: A method of processing seismic data comprises transforming seismic data which contain coherent noise to a domain in which at least some of the coherent noise is transformed to incoherent noise. The seismic data are then filtered in the new domain, to remove or attenuate the incoherent noise. If desired, the filtered data may subsequently be transformed back to the domain in which the data were acquired. The filtering process may be carried out using a multichannel interference canceller. A seismic data trace to be filtered is input to the principal channel of the interference canceller, and one or more other seismic data traces are input to the interference canceller as reference traces. Use of seismic data traces as the reference trace(s) avoids the need to determine a noise reference trace.

Abstract: VSB reception system with a frequency domain equalizer including a demodulating part for receiving, converting, and demodulating a signal, a frequency domain equalizing part for equalizing the demodulated signal for removing a distorted component from the demodulated signal, and a noise removing part for (a) receiving the equalized signal, (b) calculating a reference error signal that is a difference between the equalized signal and the signal having the noise removed therefrom, (c) calculating an error signal that is a difference between the reference error signal and the extracted noise signal, (d) renewing parameters with reference to the reference error signal and the error signal, and (e) calculating a difference between the equalized signal and the extracted noise signal, to provide a signal having the noise removed therefrom.

Abstract: An adaptive filter according to one embodiment includes an N×N two-dimensional convolution, where N is an odd integer greater than one. Pixels of an image are filtered by moving the N×N kernel across the image. At each pixel location, the kernel coefficients are determined by the image pixels within the N×N region, such that the kernel coefficients may change from one pixel location to the next. Such a filter may be implemented to use a lookup table to approximate a floating-point operation.

Abstract: It is described a method for spatially filtering 3D seabed seismic data acquired in a cross-line geometry including methods of how to decompose the data using a filter with two spatial components.

Abstract: Methods, systems, and software for generating a multi-dimensional volume are disclosed. The methods include decomposing one or more original volumes into a collection of diplets, wherein each diplet comprises information about spatial location, orientation, amplitude, wavelet, acquisition configuration, and coherency. The methods further include migrating the collection of diplets using one or more of a velocity model or an anisotropic velocity model, and synthesizing one or more of the migrated diplets to an output multi-dimensional seismic volume.

Abstract: A method for locally determining a profile of geological horizons includes a step (100) which consists in digital modeling with continuous local seismic traces, calculating an optimal offset and defining a conditional neighborhood of a reference central continuous local seismic trace; a step (101) which consists in defining residuals relative to the reference central continuous local seismic trace; a third step (102) which consists in minimizing the set of residuals on the conditional neighborhood and a fourth step (103) which consists in determining parametric coefficients corresponding to the minimization of the set of residuals on the conditional neighborhood carried out at step (102).

Abstract: In accordance with the present invention, there is provided a method of determining whether a particular high fidelity vibratory seismic survey phase encoding is likely to be a good one based on an analysis of the eigenvalue structure (i.e., eigenvalues, eigenvalue separation, condition number, and model resolution matrix) of a matrix formed from the Fourier transforms of the sweep signals. Preferably, a singular value decomposition will be used to calculate the eigenvalues. Using this same approach, the condition number and eigenvalues of matrices that are associated with multiple proposed designs can be compared with each other to determine which is likely to be yield the best seismic data. This approach is preferably used either as a component of the advanced planning for a survey or in the field during pre-survey testing. The use of the instant approach to determine an optimal phase encoding scheme is also taught.

Abstract: The invention concerns a method for smoothing a subsurface property in a geological structure represented by seismic measurements comprising a step (100) which consists in digital modelling by continuous local seismic traces, calculating an optimal offset and defining a conditional neighbourhood of a reference central continuous local seismic trace; a step (101) which consists in selecting the property to be smoothed on a conditional neighbourhood; a third step (102) which consists in substituting properties of the conditional neighbourhood with offset properties; and a fourth step (103) which consists in selecting an average of the properties offset on the conditional neighbourhood at step (102).

Abstract: The invention pertains to the sensing and measurement of infrasound (pressure variations with frequency content under 10 Hertz). The invention measures the infrasound pressure variations and then attenuates undesired contributions due to, but not limited to, changes in ambient fluid speed and changes in altitude of the sensing device. The undesired contributions are attenuated using an adaptive filter with the measurements of the change in ambient fluid speed and the change in altitude. This approach differs from existing applications of adaptive filtering in that the invention uses measurements of speed and displacement to improve a pressure measurement. This approach differs from existing methods for attenuating the affects of the wind on the measurement of infrasound in that it does not require the use of a large spatial averaging filter.

Abstract: A noise blanker (40, 106) monitors and removes noise from a sampled signal by adaptive filtering (98, 150) the sampled signal to generate trained adaptive filter prediction coefficients. The sampled signal is provided as an output signal when the noise blanker is in a training mode. A noise monitor (34, 154) detects whether noise contained within the sampled signal exceeds a predetermined threshold and provides a control signal in response to the detecting. The noise blanker is placed in a prediction mode for a predetermined amount of time in response to asserting the control signal. A prediction output signal is generated using a plurality of prediction coefficients as an all-pole filter. The prediction output signal has minimal noise content.

Abstract: A method is for use in seismic data processing includes improving the continuity of the primary events in an original seismic dataset to create a continuous, seismic dataset; predicting at least the first order multiples of the original seismic dataset from the continuous seismic dataset; deterministically matching the predicted multiples and one of the original seismic dataset or the continuous seismic dataset; and taking the difference between the matched datasets. In other aspects, an apparatus may include a computer programmed to perform to such a method and by which the seismic data may be processed. The apparatus may also include a program storage medium encoded with instructions that, when executed by a computing device, will perform the method. The data upon which the method operates may be acquired in either a land or marine survey and may be two-dimensional, three-dimensional, or four-dimensional.

Abstract: Methods of processing seismic data to remove unwanted noise from meaningful reflection signals are provided for. The methods comprise the steps of assembling seismic data into common geometry gathers in an offset-time domain without correcting the data for normal moveout. The amplitude data are then transformed from the offset-time domain to the time-slowness domain using a Radon transformation. At least of subset of the transformed data is filtered to enhance its coherent noise content and to diminish its primary reflection signal content by defining a slowness high-pass region and, a slowness low-pass region. The low-pass region is defined to enhance the low slowness coherent noise content and to diminish the primary reflection signal content thereof, thereby generating a first subset of said transformed data having enhanced low slowness coherent noise content.

Abstract: The present invention provides a method and apparatus for arriving at true relative amplitude destretched seismic traces from stretched seismic traces. The method compensates for offset varying reflection interference effects due to normal moveout. Stretch factors ? and also input spectra are determined for NMOR stretched seismic traces. Estimates are then made of stretched wavelet spectra from the input spectra. A destretched wavelet spectra is then obtained. Shaping correction factors are determined by taking the ratio of the destretched wavelet spectra to the stretched wavelet spectra and are applied to the input spectra of the stretched traces to arrive at a destretched trace spectra. True relative amplitude scaling factors are computed by taking the ratio of a true relative amplitude property of the destretched wavelet spectra to a corresponding true relative amplitude property of the stretched wavelet spectra.

Abstract: A method of beam forming an array, by computer processing a cross covariance, of the reference sub array seismic signal data signal, by having an unknown shape comprising receiving acoustic signals, via the array, and computing the data and segmenting the array into an initial segment of a known shape and at least a second segment, and beam forming the initial segment to provide a beam formed output, and using the beam formed output to obtain weights, for the second segment of the array.

Abstract: The invention provides a method and apparatus by which the direction in or the position at which a signal source such as a sound source is present is estimated. A signal or signals from a signal source or a plurality of signal sources are received by a plurality of reception apparatus, and the received signals are decomposed into signals of different frequency bands by a plurality of band-pass filters. Then, cross correlation functions between the different frequency band signals are calculated for individual combinations of the reception apparatus for the individual corresponding frequency bands. If the power of noise having no directivity is high in some of the frequency bands, then the cross correlation functions of the frequency band do not exhibit a maximum value. Therefore, an influence of the noise can be suppressed effectively when delay times of the individual reception apparatus which depend upon the direction or directions or the position or positions of the signal source or sources are estimated.