Abstract: Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for determining a velocity model for a geological region. In one aspect, a method comprises: obtaining a current velocity model for the geological region; obtaining pre-stack and post-stack seismic data characterizing the geological region; and for each of a plurality of iterations: identifying a plurality of reflection events from the post-stack seismic data and the current velocity model; determining a respective observed travel time for each of the plurality of reflection events, comprising, for each reflection event, determining the respective observed travel time for the reflection event based at least in part on kinematic features derived from a respective seismic trace included in the pre-stack seismic data; and updating the current velocity model based at least in part on the observed travel times of the plurality of reflection events.

Abstract: Embodiments herein use an acquisition vessel towing a plurality of receivers and a seismic source and a source vessel towing a seismic source to acquire seismic data corresponding to a subsurface below a bottom surface of a body of water. When activating the seismic source on the acquisition vessel, the plurality of receivers acquire survey data for a central coverage area underneath a swath defined by the plurality of receivers. However, when activating the seismic source on the source vessel, the plurality of receivers acquires survey data for a side coverage area. The embodiments herein control a separation distance between the acquisition and source vessels so that there is a gap between the central and side coverage areas resulting from activating the seismic sources towed by those vessels. This gap can reduce the cost and time required to perform the seismic survey.

Abstract: The present method predicts and separates dispersive surface waves from seismic data using dispersion estimation and is completely data-driven and computer automated and no human intervention is needed. The method is capable of predicting and suppressing surface waves from recorded seismic data without damaging the reflections. Nonlinear signal comparison (NLSC) is used to obtain a high resolution and accurate dispersion. Based on the dispersion, surface waves are predicted from the field recorded seismic data. The predicted surface waves are then subtracted from the original data.

Abstract: System and methods for automated seismic processing are provided. Historical seismic project data associated with one or more historical seismic projects is obtained from a data store. The historical seismic project data is transformed into seismic workflow model data. At least one seismic workflow model is generated using the seismic workflow model data. Responsive to receiving seismic data for a new seismic project, an optimized workflow for processing the received seismic data is determined based on the at least one generated seismic workflow model. Geophysical parameters for processing the seismic data with the optimized workflow are selected. The seismic data for the new seismic project is processed using the optimized workflow and the selected geophysical parameters.

Abstract: A method of monitoring a marine animal in a marine environment, implemented by an interrogator unit and a sensing attached to the interrogator, the method comprises deploying the sensing cable within a water column, interrogating, using the interrogator unit, the sensing cable, receiving acoustic data comprising acoustic signals generated by the marine animal, and processing, by a processor coupled to the interrogator unit, the acoustic data to detect a presence of the marine animal.

Abstract: A method, and a system for implementing the method, are disclosed wherein coordinates of survey region are used to locate small pieces of a seismic wave model, usually defined by their nodes (or vertices) and contain information about physical properties, such as liquid or solid, density, velocity that seismic waves propagates in it; and connects them to the appropriate source and receiver sensor. In particular, the method and system disclosed, generates a multi-layer mapping of the survey region by decomposing the survey region into cubes containing small pieces of seismic wave models (the elements), as well as source and receiver location. Those cubes are then indexed depending upon their location and the elements, sources and receivers are assigned to a particular cube thereby creating a multi-layer relationship between the survey region map, the cube map, the elements map, as well as the source and receiver locations.

Abstract: Techniques are disclosed for reducing noise when computing time-lapse differences between two or more geophysical surveys performed over the same region. In some computer-implemented embodiments, a time-lapse difference is determined between first and second data representing the first and second surveys, respectively. Based on geometry information corresponding to the second survey, first estimated data is generated representing how the first data would have looked if the second survey geometry had been used during the first survey. A noise model is generated based on differences between the first data and the first estimated data. The time-lapse difference is then adjusted using the noise model, thereby reducing noise in the time-lapse difference caused by differences between the geometries of the first and second surveys.

Abstract: Methods are presented for determining the location of underground features (e.g., CO2). One method includes capturing, by sensors distributed throughout a region, seismic traces associated with seismic signals generated by a seismic source. For multiple sensors, active noise is identified or passive noise is measured within each seismic trace and values for attributes associated with the active or passive noise are determined. Further, an unsupervised machine-learning model, based on the values of the attributes, is utilized to determine noise characteristics for multiple sensors. The sensors are grouped in clusters based on the noise characteristics for each sensor. For multiple clusters, a noise filter is created based on the noise characteristics of the sensors in the cluster, and the noise filter of the cluster is applied, for multiple sensors, to the seismic traces of the sensor. Additionally, the filtered seismic traces are analyzed to determine a location of CO2 underground.

Abstract: Systems, methods, and computer-readable media for the attenuation of interface waves using polarization filtering applied to recorded single component seismic data are disclosed. A second component for polarization filtering is created by determining interface waves from the recorded data single component seismic data. The second component seismic data may be generated using an interface waves propagation model (in frequency or time-frequency domain) or by differential normal move-out (NMO) interpolation. Polarization filtering may be applied to multicomponent seismic data formed from the recorded single component seismic data and the generated second component seismic data to attenuate interface noise.

Abstract: A device may include a processor that may recover the signals misallocated in the deblending process of seismic data acquired with simultaneous sources. The processor may update the primary signal estimate based at least in part on a separation operation that separates coherence signals from noise signals in an output associated with the residual determined to be remaining energy for separation. The processor may be incorporated into the iterative primary signal estimate of the deblending process or be applied towards preexisting deblending output. In response to satisfying an end condition, the processor may transmit a deblended output that includes the weak coherence signals recovered from the misallocation or error in the primary signal estimate. The processor may also transmit the deblended output for use in generating a seismic image. The seismic image may represent hydrocarbons in a subsurface region of Earth or subsurface drilling hazards.

Abstract: A method and a system for implementing the method are disclosed wherein the pre-stack seismic input data, an initial anellipticity anisotropy parameter, and a baseline normal moveout velocity from a non-flat surface, are sometimes mild or foothill topography as well as the shot and receiver lines might not necessarily be straight, and often curve to avoid obstacles on the land surface. In particular, the method and system disclosed, allows for updating the anisotropy parameters iteratively and when the stopping criteria is satisfied, the final estimated parameter can be directly used for time migration. This method and system are mainly used for time migration with the purpose of obtaining the high fidelity (accurate amplitude, i.e. not only travel-time correct but also amplitude correct) image gathers which are used for reservoir characterization and interpretation.

Abstract: A method for displaying slowness data after defects of anisotropy and heterogeneity have been removed includes visually depicting a slowness image on a computer monitor in which the slowness image includes a log of slowness values at a plurality of depths of a wellbore and a plurality of azimuth angles about a periphery of the wellbore. The image is processed via filtering such as with a bandpass filter. The filter may be obtained via fitting a periodic function to the slowness values at each depth or via a selected periodicity value and center angle. A resultant image is displayed.

Abstract: Graph database analysis for network anomaly detection systems, in which a data analysis device receives multiple log data entries including parameters associated with a computer network event in a computing network. The data analysis device extracts one or more parameters in real-time and generates a network event graph based on at least one of a first graph metric or a second graph metric. The first and second graph metrics are based on the one or more extracted parameters. The data analysis device detects, based on queries performed on the network event graph, at least one of an anomalous event associated with the computing network or a malicious event associated with the computing network.

Abstract: In a method for deghosting seismic data acquired by a marine seismic source and receiver assembly effects of seismic reflections by the water surface, known as ghost signals, are removed by a deghosting algorithm, which transforms input seismic data with the surface ghost reflections into source- and receiver-deghosted seismic data using a sparse-inversion technique both for hydrophone and/or geophone recordings, which technique includes equation (26), thereby considerably improving usuable bandwidth and giving rise to a significant imaging uplift.

Abstract: Computing device, computer instructions and method for removing cross-talk noise from seismic data and generating an image of a surveyed subsurface. The method includes receiving input seismic data D generated by firing one or more seismic sources so that source energy is overlapping, and the input seismic data D is recorded with seismic sensors over the subsurface; generating a cross-talk noise model N by replacing at least one original shot gather with a reconstructed shot gather; subtracting the cross-talk noise model N from the input seismic data D to attenuate coherent cross-talk noise to obtain processed seismic data Dp; deblending the processed seismic data Dp with a deblending algorithm to attenuate a residual noise to obtain deblended seismic data Dd; and generating the image of the subsurface based on the deblended seismic data Dd.

Abstract: The present disclosure describes methods and systems for interpreting geological features in a seismic volume based on mono-frequency filtering of the seismic volume. One computer-implemented method includes receiving a seismic data volume, decomposing the seismic data volume into multiple sub-volumes, generating one or more seismic horizons on each sub-volume, analyzing the generated seismic horizons for the multiple sub-volumes including determining a first sub-volume and a second sub-volume from the multiple sub-volumes, and subtracting the generated one or more seismic horizons for the first sub-volume from the generated one or more seismic horizons for the second sub-volume.

Abstract: The present invention discloses a near-sea-bottom hydrate detection system, which includes a ship-borne part and a deep-towing part. The ship-borne part includes: a comprehensive monitoring host, configured to send an acquisition triggering pulse signal, and transmit the signal to the deep-towing part; and receive near-sea-bottom information acquired by the deep-towing part, and determine a near-sea-bottom condition according to the near-sea-bottom information.

Abstract: A system for processing DAS VSP surveys is provided. The system includes a DAS data collection system coupled to at least one optical fiber at least partially positioned within a wellbore and configured to either activate or passively listen to a seismic source of energy for one or more times. The system further includes an information processing system connected to the DAS data collection system. A seismic dataset is received from the DAS data collection system recorded in a spatiotemporal domain. The seismic dataset is converted into intercept-time ray-parameter domain dataset. Local apparent slope is determined for each seismic signal in the received seismic dataset. Amplitude correction is performed for the received seismic signals by using the slowness profile and the determined local apparent slope in the intercept-time ray-parameter domain dataset. The corrected intercept-time ray-parameter domain dataset is converted back into the spatiotemporal domain.

Abstract: The present disclosure describes methods and systems, including computer-implemented methods, computer program products, and computer systems, for image-guided velocity interpolation using a mask cube. One computer-implemented method includes generating a 3D array of velocities, generating a mask for the 3D array of velocities, each value in the 3D array of velocities associated with a corresponding value in the mask, calculating a 3D array of diffused velocities by applying structure oriented smoothing to the 3D array of velocities, calculating a diffused mask by applying the structure oriented smoothing to the mask, and calculating interpolated velocity values based on the 3D array of diffused velocities and the diffused mask.

Abstract: Post-stack seismic data is received. Transformed seismic data is created from the received post-stack seismic data, including performing a super-resolution radon transform on the post-stack seismic data. Signal and noise regions are separated using the transformed seismic data, including using a defined muting function to remove unwanted noise. An inverse radon transform is performed using the separated signal and noise regions, outputting only signals.

Abstract: The present disclosure describes methods and systems, including computer-implemented methods, computer program products, and computer systems, for generating geophysical images.

Abstract: A technique for estimating a depth of investigation of a seismic survey includes in various aspects a method and an apparatus. The method is for use in seismic exploration and includes: forward modeling on a subsurface attribute model of a subterranean region to generate a set of low frequency seismic data, the subsurface attribute model being generated from data representative of the subterranean region; performing a reverse time migration on the low frequency seismic data to obtain a plurality of gathers with large opening angles; stacking the gathers to yield a diving wave illumination image; and estimating a full-waveform inversion depth of investigation from the diving wave illumination image. The apparatus may include a computing apparatus programmed to perform the method and/or a program storage medium encoded with computing instructions that, when executed, perform the method.

Abstract: Described herein is a method for determining a higher order resonance mode frequency of a haptic actuator for an electronic device. The higher order resonance mode frequency may correspond to a frequency in which a mass of the haptic actuator exhibits undesired movement. The movement may cause the mass to collide or otherwise impact an enclosure of the haptic actuator. Once the higher order resonance mode frequency is determined, a delay or a polarity inversion may be added to one or more of a series of input waveforms to suppress or brake the undesired movement.

Abstract: The present disclosure discloses a method and an apparatus for processing seismic data, and belongs to the field of geological surveys. The method comprises: stacking seismic trace gathers in a predetermined range among S seismic trace gathers after a Normal Move Out (NMO) correction processing to obtain a model trace, S being an integer; calculating a correlation coefficient of each seismic trace gather with the model trace, and selecting a K-th seismic trace gather with a maximum correlation coefficient; calculating an optimum point of each seismic trace gather from the K-th seismic trace gather to two sides orderly; and performing a residual NMO correction of the seismic trace gathers according to the optimum points.

Abstract: A preserved-amplitude RTM-based FWI method is used to obtain an image of an explored subsurface formation. Model data corresponding to detected data is generated using a velocity model of the formation. Residuals representing differences between the modeled data and the detected data are back-propagated to then update the velocity model a local optimization based on a deconvolution formula employing a backward propagating wavefield and a forward propagating wavefield. Geophysical features of the formation are imaged based on the updated velocity model.

Abstract: Methods of acquiring and processing seismic data using derivative sensors, such as strain sensors, that facilitate ground roll noise attenuation with seismic interferometry are disclosed. The methods use both seismic data and their spatial derivatives in computing ground-roll noises which are removed from processed seismic data.

Abstract: Surface wave coda in seismic data recorded with a data acquisition system over an underground formation is estimated using time-reversal experiments. First time-reversal experiments use a first time-reversal mirror including a target source and one or more other sources to obtain estimates of surface waves traveling from other receivers to a target receiver. Second time-reversal experiments obtain a coda estimate for a surface wave traveling from the target source to the target receiver using a second time-reversal mirror including the target receiver and the other receivers.

Abstract: Methods for correcting seismic signals by determining a signature of an outcropping geobody (e.g., a sand dune) from unprocessed seismic data, attenuating the seismic data using a variable gap deconvolution, and performing a surface consistent deconvolution and amplitude correction on the seismic data. A signature associated with the outcropping geobody and corresponding to the geometry of the geobody may be identified from the unprocessed seismic data. The signature may be used in subsequent processing, such for the determination of a variable gap length for a variable gap deconvolution applied to the seismic data. Computer-readable media and systems for correcting seismic signals are also provided.

Abstract: Disclosed is a method of, and computer program and apparatus for, identifying reflected signals, subsequent to their reflection within a medium. The method comprises obtaining return signals (100), resulting from measurements being performed over a measurement period. The measurement period comprises sub-periods, the return signals comprising reflected signals and noise. The plurality of return signals are partitioned into plural sets (220) of equal cardinality or as equal as possible such that their cardinality differs by no more than one. A stacked correlation value is determined (130) for the return signals by determining the mean of the return signals across the plural sets (230) and determining a correlation value of the plural sets over each of the time sub-periods (240). Peaks in the variation of the stacked correlation value over time can then be identified and each of the peaks in the variation of the stacked correlation value over time can be attributed to a reflected signal.

Abstract: A system for attenuating coherent noise from seismic data comprises one or more sensors configured to sense waves generated by a seismic source and a coherent noise attenuation module communicably coupled to the one or more sensors and comprising a processor and memory. The coherent noise attenuation module is operable to receive a plurality of traces of seismic data from the one or more sensors and apply a first transformation to the plurality of traces, identify one or more outlier waveforms in the transformed traces, attenuate the identified outlier waveforms, and apply a second transformation to the plurality of traces that is the inverse of the first transformation.

Abstract: Methods and systems of generating seismic images from primaries and multiples are described. Methods separate pressure data into up-going pressure data and down-going pressure data from pressure data and vertical velocity data. Irregularly spaced receiver coordinates of the down-going and up-going pressure data are regularized to grid points of a migration grid and interpolation is used to fill in down-going and up-going pressure data at grid points of the migration grid. A seismic image is calculated at grid points of the migration grid based on the interpolated and regularized down-going pressure data and the interpolated and regularized up-going pressure data. The seismic images are high-resolution, have lower signal-to-noise ratio than seismic images generated by other methods, and have reduced acquisition artifacts and crosstalk effects.

Abstract: Methods for processing seismic data acquired with non-impulsive moving sources are provided. Some methods remove cross-talk noise from the seismic data using emitted signal data and an underground formation's response estimate, which may be iteratively enhanced. Some methods perform resampling before a spatial or a spatio-temporal inversion. Some methods compensate for source's motion during the inversion, and/or are usable for multiple independently moving sources.

Abstract: A technique includes spatially filtering a signal that is derived from a seismic acquisition. The filtering is associated with a filter length, and the filtering includes varying the filter length with frequency. The filtering may be used in connection with adaptive noise attenuation, which is applied to decomposed subbands. Furthermore, the filtering may be applied during the reconstruction of the signal from the subbands.

Abstract: A method and system of processing seismic data is presented. The method may include, for each of a plurality of seismic traces, generating a respective intermediate set of reflectivity coefficients and a partial deconvolution of an estimated wavelet from the respective seismic trace. The method may also include decomposing a model into a plurality of orthogonal components, and projecting each of a plurality of eigenvectors corresponding to one of the orthogonal components onto intermediate reflectivity coefficients corresponding with all of the plurality of seismic traces at each of a plurality of times to generate a plurality of eigen-coefficients associated with each of the plurality of times. The eigen-coefficients may be used to generate a plurality of basis coefficients, which may then be used to generate a respective updated set of reflectivity coefficients for each of the seismic traces.

Abstract: Methods and systems for optimized receiver-based ghost filter generation are described. The optimized ghost filter self-determines its parameters based on an iterative calculation of recorded data transformed from a time-space domain to a Tau-P domain. An initial ghost filter prediction is made based on generating mirror data from the recorded data and using a least squares technique during a premigration stage.

Abstract: A method for removing internal multiples from collected data, such as seismic data. The method includes predicting internal multiples for each horizon in a plurality of horizons that created the internal multiples. The internal multiples may be predicted from the seismic data in one pass. After predicting the internal multiples, the method includes creating a separate model of internal multiples for each horizon based on the predicted internal multiples for each horizon. The method then iteratively subtracts each separate model of internal multiples for each horizon from the seismic data.

Abstract: An example method includes acquiring two-dimensional (2D) or three-dimensional (3D) digital images of a rock sample. The method also includes iteratively analyzing property measurements collected throughout the digital images using different subsample sizes to identify a property distribution convergence as a function of subsample size. The method also includes selecting a smallest subsample size associated with the property distribution convergence as a representative elementary area or volume for the rock sample.

Abstract: A method includes accessing a seismic image comprising a plurality of features of interest. The method also includes defining a plurality of configuration files for a plurality of graphical models. The method further includes applying the plurality of graphical models to the seismic image. The method also includes generating a plurality of scores for each feature of interest, wherein each graphical model generates a score for each feature of interest. The method further includes combining the plurality of scores for each feature of interest into a plurality of combined scores, wherein each feature of interest has a combined score.

Abstract: There is a method for generating a final image of a subsurface of the earth. The method includes receiving measured seismic data d of the subsurface; selecting an objective function E that is function of a reflectivity r of the subsurface; and calculating, in a processor, the reflectivity r based on the measured seismic data d, the objective function E, simulated data {tilde over (d)}, a modeling operator M from a reverse time demigration (RTDM) process and an imaging operator MT from a reverse time migration (RTM) process.

Abstract: A technique includes generating vibroseis sweeps for a vibroseis survey to produce seismic data acquired in response to seismic signals produced by the sweeps. The generation of the vibroseis sweeps including temporally arranging the sweeps into time-overlapping groups. The technique includes regulating a timing of the groups relative to each other based on a slip time. The technique also includes regulating a timing of the sweeps of each group such that consecutive sweep firings of each group are spaced apart by a time substantially less than the slip time.

Abstract: An acquisition effect of a marine survey measurement can be parameterized as a function of time to define a parameterized acquisition effect and a subsurface effect of the marine survey measurement can be parameterized as a function of position to define a parameterized subsurface effect. The acquisition effect and the subsurface effect can be estimated based on the parameterized acquisition effect and the parameterized subsurface effect to define an estimated acquisition effect and an estimated subsurface effect, respectively. The estimated acquisition effect can be removed from the marine survey measurement.

Abstract: A method of processing data from a distributed fibre-optic interferometric sensor system for measuring a measurand, the system comprising multiple interferometric sensors. The method comprises interrogating two or more of the multiple interferometric sensors to record a raw measurement time series for each of the sensors. The method further comprises calculating a common reference time series as a measure of central tendency of the raw measurement time series from two or more reference sensors, the reference sensors being selected from the multiple interferometric sensors. Finally, the method comprises compensating at least one raw measurement time series from a measurement sensor selected from the multiple interferometric sensors with the common reference time series to produce a compensated measurement time series, the measurement sensor being configured to be sensitive to the measurand. The invention further relates to a distributed fibre-optic interferometric sensor system.

Abstract: A system, method and computer program product for seismic imaging implements a seismic imaging algorithm utilizing Reverse Time Migration (RTM) and Full Waveform Inversion (FWI) techniques requiring large communication bandwidth and low latency to convert a parallel problem into one solved using massive domain partitioning. Since in RTM and FWI, the forward wave propagation is iteratively calculated on time step increments, there are very high statistical correlation between the intermediate wavefields at the adjacent time steps. This correlation is exploited in compression of the intermediate wavefields so as to achieve much higher compression ratio and avoid the disk IO bottleneck and reduce the overall computing time substantially. Further, during simulation of a reverse wavefield, reverse predictive encoding technique is performed such that snapshots are not recovered in the reverse propagation path due to a prediction chain.

Abstract: Method for acquiring, at reduced acquisition cost, seismic data using simultaneous, field-encoded sources in the field (702), and then constructing pseudo source-records (703) that better meet the requirements for using additional simultaneous computer-encoded sourcing for computer simulations or forward modeling (706) as part of (707) iterative FWI (Full Wavefield Inversion) or RTM (Reverse Time Migration), with additional reduction in computational costs. By better meeting the requirements of simultaneous sourcing for FWI or RTM (701), artifacts and crosstalk are reduced in the output. The method can be used for marine streamer acquisition and other non-fixed spread geometries to acquire both positive and negative offsets and to mitigate the “missing data” problem for simultaneous-source FWI. It can also be used for land data to overcome issues with moving spreads and long continuous records.

Abstract: There is provided herein a new system and method of local attribute match filtering which operates in the local attribute domain via the use of complex wavelet transform technology. This approach is adaptable to address various noise types in seismic data and, more particularly, is well suited to reduce the noise in geophone data as long as an associated hydrophone signal is relatively noise-free.

Abstract: Seismic image filtering machines, systems, program products, and computer implemented methods are provided to generate a filtered seismic image responsive to filtered seismic image data generated by attenuating coherent seismic noise from surface waves of an unfiltered wavefield constructed from unfiltered seismic image data through a single downward extrapolation of the unfiltered wavefield using a plurality of nonstationary convolution operators to perform localized filtering at each of a plurality of spatial locations of the unfiltered wavefield. Various embodiments, for example, can beneficially handle strong lateral velocity variations thus making various embodiments effective tools to remove complicated coherent seismic noise which is typically in the form of exponentially decaying evanescent waves.

Abstract: Method for using the full wavefield (primaries, internal multiples and free-surface multiples) in inversion of marine seismic data, including both pressure and vertical velocity data (21), to infer a subsurface model of acoustic velocity or other physical property. The marine seismic data are separated (22) into up-going (23) and down-going (24) wavefields, and both wavefields are inverted in a joint manner, in which the final model is impacted by both wavefields. This may be achieved by inverting both wavefields simultaneously (25), or one after the other, i.e. in a cascaded approach (35?37, or 45?47), for the subsurface properties (26, 38, 48).

Abstract: A method for characterizing subsurface formations penetrated by a wellbore includes accepting as input to a computer measurements of a physical parameter of the formations made over a selected axial interval of the wellbore. At least one attribute of the measurements is determined from a change in the measurements over the selected axial interval. At least one characteristic of the formations in the selected axial interval using the at least one attribute.

Abstract: Methods and systems for shear noise attenuation based on matching vertical particle velocity data and pressure data are described. The shear noise attenuation is based on the fact that different stages of the analysis can be performed with different numbers of wavelet orientations. The analysis is performed for frequency sub-bands for all wave numbers and vice versa.

Abstract: A method for determining event counts for a database system includes capturing samples for the active sessions based on a pre-defined sampling frequency and identifying events from the captured samples. The method further includes determining the wait time for each of the identified events and determining an event count for the active sessions using a harmonic mean. The harmonic mean is a summation of the maximum of either one or the ratio of the sampling frequency to the determined wait time for each of the identified events.