Abstract: Techniques are disclosed relating to acquisition and imaging for marine surveys. In some embodiments, a transition survey that uses both one or more sources of a first type (e.g., impulsive sources) and one or more sources of a second type (e.g., vibratory sources) may facilitate calibration of prior surveys that use the first type of sources with subsequent surveys that use the second type of source. In some embodiments, the different types of sources may be operated simultaneously at approximately the same location. In some embodiments, signals generated by the sources are separated, e.g., using deconvolution. The signals may then be compared to generate difference information, which in turn may be used to adjust sensor measurements from a previous or subsequent survey. In various embodiments, the disclosed techniques may improve accuracy in images of geological formations and may facilitate transitions to new types of seismic sources while maintaining continuity in 4D surveys.

Abstract: A method for fluid identification and saturation estimation in subsurface rock formations using the Controlled Source Electromagnetic (CSEM) data and Seismic Data by calculating the fluid saturation (Sfl) in a reservoir given the resistivity obtained from CSEM data, and acoustic impedance obtained from the seismic data, comprising the following steps: a) obtaining wireline data within a zone of interest in a nearby well and determining the resistivity of water by calibrating the background resistivity trend with a reference Sfl curve, b) obtaining inverted CSEM survey data from a subsurface zone of interest, c) obtaining inverted seismic data in the form of Acoustic Impedance (AI), d) bringing both the inverted CSEM and acoustic impedance data to a same domain; time or depth, f) calculating fluid saturation using a rock physics model inputting the resistivity of water along with inverted CSEM and acoustic impedance data, resulting in a Sfl profile.

Abstract: Methods and systems for determining an interbed multiple attenuated pre-stack seismic dataset are disclosed. The methods include forming a post-stack seismic image composed of post-stack traces from the pre-stack seismic dataset and identifying a first, second, and third post-stack horizon on each of the post-stack traces. The methods further include for each pre-stack trace, generating a first, second, and third multiple-generator trace based on the first, second and third post-stack horizon and determining a correlation trace based, at least in part, on a correlation between the first multiple-generator trace and the second multiple-generator trace.

Abstract: Systems and methods include creation of a first target table in a target system, the first target table having a structure of a first source table and loaded with data of the first source table, creation of a view in the target system, the view having a name of the first source table and configured to select from the first target table, reception of a request to reload a current version of the first source table into the target system, and, in response to the request, creation of a second target table in the target system, the second target table having a structure of the current version of the first source table, copying of data of the current version of the first source table to the second target table while the view is configured to select from the first target table, and, after copying of the data of the current version of the first source table to the second target table is complete, modification of the view to select from the second target table.

Abstract: A method for performing a formation-related operation based on corrected vertical seismic profile (VSP) data of an earth formation includes performing a VSP survey and applying a normal moveout (NMO) correction equation to the survey data that is a function of source offset to wellhead. The method also includes solving the NMO correction equation using a simulated annealing algorithm having an object function that is a coherence coefficient of semblance analysis of an NMO corrected reflection event within a time window to provide NMO corrected data. The method further includes performing the formation-related operation at at least one of a location, a depth and a depth interval based on the VSP NMO corrected data.

Abstract: A method of performing single trace inversion to characterize changes in a subsurface region includes obtaining a base seismic trace and a monitor seismic trace of the subsurface region at different respective times. The method includes generating a predicted monitor seismic trace from the base seismic trace by a process including applying a time shift to the base seismic trace, the time shift being derived from estimated velocity perturbations occurring between the base seismic trace and the monitor seismic trace, compensating for amplitude changes between the base seismic trace and the monitor seismic trace, wherein the time shift is applied to the amplitude changes, and minimizing a difference between the predicted monitor seismic trace and the monitor seismic trace by iteratively estimating the velocity perturbations to obtain final estimated velocity perturbations. Changes of at least part of the subsurface region may be characterized using the final estimated velocity perturbations.

Abstract: A method for predicting a stress attribute of a subsurface earth volume includes simulating a linearly independent far field stress model, a discontinuity pressure model, and a discontinuity pressure shift model for the subsurface earth volume. A stress value, a discontinuity pressure shift at a surface of the Earth, a strain value, a displacement value, or a combination thereof is computed for data points in the subsurface earth volume based on a superposition of the linearly independent far field stress model, the discontinuity pressure models, and the discontinuity pressure shift model. The stress attribute of the subsurface earth volume is predicted, based on the computed stress value, the computed discontinuity pressure shift at the surface of the Earth, the computed strain value, the computed displacement value, or the combination thereof.

Abstract: A process for seismic imaging of a subterranean geological formation includes generating a source wavefield from seismic data representing a subterranean formation. The process includes generating a receiver wavefield from the seismic data representing the subterranean formation. The process includes decomposing the source wavefield to extract a source depth component and decomposing the receiver wavefield to extract a receiver depth component. The process includes applying a transform to each of the source depth component and the receiver depth component. The process includes combining the source depth component and the receiver depth component to generate an imaging condition. The process includes extracting a low-frequency term from the imaging condition to generate a wave-path tracking data, generating a wave path from the wave-path tracking data, and rendering a seismic image of at least a portion of the subterranean geological formation from the generated wave path.

Abstract: A computer-implemented method includes the following. A frequency sweep using sweep parameters is emitted from a vibratory seismic source into geological layers. The sweep parameters include frequencies and modulation parameters for seismic waves. Signals are received from one or more sensors. The signals include seismic data acquisition information, including values identifying energy reflected back from boundaries where rock properties change. A determination is made regarding which of the reflected seismic waves are attenuated. The determination uses an integral transform and a thresholding algorithm for image segmentation. Optimum sweep parameters are determined based on the reflected seismic values that are attenuated and updated to compensate for local geology effects. The emitting, receiving, determining attenuation, determining optimum parameters, and updating are repeated until the received signals are determined to be satisfactory.

Abstract: Real-time data of drilling operations may be utilized to automatically fingerprint and evaluate their values to create enhanced information of interest. Enhanced information of interest may be comparable to given procedure and may facilitate generation of actionable insight and validation of procedural compliance. Real-time data of drilling operations may be analyzed to generate analysis and graphical comparison of specific sub-step operations that make up activities of interest. These operations may correspond to specific actions a driller on a rig may take to manipulate equipment and may be documented as procedural steps.

Abstract: A long offset land seismic survey spread includes a plurality of sensors within an area thereby defining a sensor receiver patch, a plurality of long offset sensor receivers outside of the receiver patch thereby surrounding the receiver patch and defining a sensor long offset area that is fee from sensor receivers that also defines a distance separating an external border of the sensor receiver patch and the long offset sensor receivers being a minimum offset distance that is a long offset distance.

Abstract: Seismic survey data is received, indexed into index sets, and each index set partitioned into data blocks. For each particular data block of a particular index set, the particular data block is sliced into frequency slices. For each particular frequency slice of the particular data block, the particular frequency slice is processed to remove random and erratic noise by: forming a Hankel matrix from the particular frequency slice: determining an optimal rank for the Hankel matrix, determining a clean signal and erratic noise from the ranked Hankel matrix, and returning the clean signal and erratic noise for the particular frequency slice. A clean signal is assembled from the index sets.

Abstract: Prestack images from the object store are hierarchically combined to generate a hierarchically stacked image. The hierarchically stacked image is generated by combining stacked images that includes a stacked image. The stacked image is generated by combining at least the prestack images. Based at least on the hierarchically stacked image, a quality measure of a prestack image is generated. Prior to deleting at least a subset of the prestack images from the object store and based at least on the quality measure, the prestack images are further combined to generate an enhanced stacked image. The stacked image is substituted using the enhanced stacked image. Subsequent to the substituting and prior to deleting at least the subset of the stacked images from the object store, the stacked images are combined to generate an enhanced hierarchically stacked image. The enhanced stacked image and the enhanced hierarchically stacked image are generated using failure recovery metadata.

Abstract: A method for deblending seismic signals includes entering as input to a computer recorded signals comprising seismic energy from a plurality of actuations of one or more seismic energy sources. A model of deblended seismic data and a blending matrix are initialized. A blending matrix inversion is performed using the initialized model. The inversion includes using a scaled objective function. The inversion is constrained by a thresholding operator. The thresholding operator is arranged to recover coefficients of the model of the deblended seismic data that are substantially nonzero, against a Gaussian white noise background. The thresholded model is projected into data space. Performing the blending matrix inversion is repeated if a data residual exceeds a selected threshold and the inversion is terminated if the data residual is below the selected threshold. At least one of storing and displaying an output of the blending matrix inversion is performed when the blending matrix inversion is terminated.

Abstract: Disclosed are methods, systems, and computer-readable medium for a full seismic wavefield de-aliasing workflow. To achieve the de-aliasing, the workflow employs a four-dimension (4D) anti-leakage anti-aliasing regularization algorithm. The workflow involves application of successive de-aliasing steps while restricting computations only to the significant spatial dimensions. In areas of strong elastic property variation in the near-surface, the benefit of de-aliasing the full wavefield is both significant and demonstrable. In addition to achieving de-aliased sampling of the full wavefield, the workflow reduces the complexity of both the computational and geophysical aspects of the problem of de-aliasing full wavefields.

Abstract: PP and PS seismic data are jointly inverted in a stratigraphic grid, using different time axes for PP and PS reflections. A ratio of PP and of PS waves'travel times inside a same layer cell maintained to be a function of a ratio of a P-wave propagation velocity and of an S-wave propagation velocity therein. Since PP and PS seismic amplitudes and travel times are due to elastic properties of the same structure, they can be inverted at the same time to provide better estimates of these elastic properties.

Abstract: The present disclosure includes a method for combining controlled and uncontrolled seismic data. The method includes accessing one or more controlled signals, each controlled signal associated with a respective receiver of a plurality of receivers. The method also includes accessing one or more uncontrolled signals, each uncontrolled signal associated with a respective receiver of the plurality of receivers. The method also includes generating one or more reconstructed signals based on the one or more uncontrolled signals. The method also includes generating a composite image based at least on the one or more controlled signals and the one or more reconstructed signals. The present disclosure may also include associated systems and apparatuses.

Abstract: Seismic shot gather data is received from a computer data store for processing. The received seismic shot gather data is separated into downgoing and upgoing wavefields, a time-frequency-wavenumber (t-f-k) three-dimensional (3D) data cube comprising multiple time-frequency (t-f) slices is formed. The downgoing wavefields are wavelet transformed from a time (t) domain to a t-f domain and the upgoing wavefields are wavelet transformed from the t domain to the t-f domain. A wavelet cross-correlation is performed between the downgoing wavefields in the t-f domain and the upgoing wavefields in a t-f-k domain to generate wavelet cross-correlated data. Soft-threshold filtering if performed for each t-f slice of the t-f-k 3D data cube. An inverse wavelet transform is performed to bring wavelet cross-correlated data from the t-f-k domain to a time-receiver (t-x) domain.

Abstract: A surface-consistent refraction analysis automatically derives near surface corrections during seismic data processing. Residual time lags are evaluated in multiple CMP-offset-azimuth bins by similarity analysis with a pilot trace where a correlation window is centered at the refracted arrival. The similarity analysis may take the form of computerized cross-correlation, or other criteria such as semblance. The residuals are then used to build a system of linear equations that is simultaneously inverted for surface-consistent shot and receiver time shift corrections plus a possible subsurface residual term. The refraction analysis steps are completely automated and require a fraction of the time needed for conventional near surface analysis.

Abstract: A technique includes determining at least one impulse response of a modeling and migration of at least one point scatterer in a target structure and based at least in part on the impulse response(s) and a reflection amplitude image, determining a model for at least part of the target structure.

Abstract: A surface-consistent refraction analysis automatically derives near surface corrections during seismic data processing. Residual time lags are evaluated in multiple CMP-offset-azimuth bins by similarity analysis with a pilot trace where a correlation window is centered at the refracted arrival. The similarity analysis may take the form of computerized cross-correlation, or other criteria such as semblance. The residuals are then used to build a system of linear equations that is simultaneously inverted for surface-consistent shot and receiver time shift corrections plus a possible subsurface residual term. The refraction analysis steps are completely automated and require a fraction of the time needed for conventional near surface analysis.

Abstract: Systems and methods to correct misties across multiple 2D seismic surveys using a correction solution calculated based only on the intersecting points between different surveys.

Abstract: A method of subsurface exploration includes generating a representation of a portional volume of the Earth from a seismic measurement of a physical parameter.

Abstract: A method includes receiving data indicative of outputs of first and second seismic sensors. The outputs include components corresponding to the detection by the first and second seismic sensors of first and second seismic signals. In addition, the method includes identifying, relative to a first clock in the first seismic sensor, a first time associated with a time of arrival of the first seismic signal at the first seismic sensor, and a second time associated with a time of arrival of the second seismic signal at the first seismic sensor. Further, the method includes identifying, relative to a second clock in the second seismic sensor, a third time associated with a time of arrival of the first seismic signal at the second seismic sensor, and a fourth time associated with a time of arrival of the second seismic signal at the second seismic sensor. Still further, the method includes determining an offset of the first clock relative to the second clock using the first, second, third and fourth times.

Abstract: A method is described for a manner of geologic analysis using seismic data. The method includes steps to produce improved amplitude versus angle (AVA) information that may be used for analysis of geologic features of interest including estimation of pore fluid content. The method assesses the probability of hydrocarbons in a subterranean reservoir based on seismic amplitude variations along offsets or angles for portions of a seismic horizon. The method may be executed by a computer system.

Abstract: A method of geophysical exploration in a seismic survey includes acquiring a set of seismic traces based on seismic data obtained by a seismic receiver, responsive to seismic energy reflected from a subsurface geology. Additional steps include performing reverse time migration on the seismic traces using a velocity model that represents velocity of the seismic energy propagating through the seismic medium. The migrated gathers have an amplitude based at least in part on the migration, which can be corrected by computing synthetic seismograms to provide compensated gathers. Amplitude versus offset and/or amplitude versus angle analysis can be performed on the compensated gathers, in order to generate a seismic image of subsurface structures in the survey area.

Abstract: Techniques herein partition data using data repartitioning that is store-and-forward, content-based, and phasic. In embodiments, computer(s) maps network elements (NEs) to grid points (GPs) in a multidimensional hyperrectangle. Each NE contains data items (DIs). For each particular dimension (PD) of the hyperrectangle the computers perform, for each particular NE (PNE), various activities including: determining a linear subset (LS) of NEs that are mapped to GPs in the hyperrectangle at a same position as the GP of the PNE along all dimensions of the hyperrectangle except the PD, and data repartitioning that includes, for each DI of the PNE, the following activities. The PNE determines a bit sequence based on the DI. The PNE selects, based on the PD, a bit subset of the bit sequence. The PNE selects, based on the bit subset, a receiving NE of the LS. The PNE sends the DI to the receiving NE.

Abstract: Techniques for processing multi-source traces from computing systems are disclosed. One example technique includes receiving a user command to align a first event from a first trace to a second event from a second trace. The first trace has a first anchor event temporally aligned with a second anchor event of the second trace. The technique also includes setting a time in a timestamp of the first anchor event as a base time, calculating first and second differences between times in timestamps of the first and second events relative to the base time, respectively, deriving a ratio between the first difference and the second difference, and scaling time intervals between adjacent events of the second trace using the derived ratio such that the second event from the second trace is temporally aligned with the first event of the first trace while the first and second anchor events remain temporally aligned.

Abstract: Techniques for processing multi-source traces from computing systems are disclosed. One example technique includes receiving a user command to align a first event from a first trace to a second event from a second trace. The first trace has a first anchor event temporally aligned with a second anchor event of the second trace. The technique also includes setting a time in a timestamp of the first anchor event as a base time, calculating first and second differences between times in timestamps of the first and second events relative to the base time, respectively, deriving a ratio between the first difference and the second difference, and scaling time intervals between adjacent events of the second trace using the derived ratio such that the second event from the second trace is temporally aligned with the first event of the first trace while the first and second anchor events remain temporally aligned.

Abstract: The present application provides a method and device for determining overall metrics of seismic geometry repeatability, wherein the method comprises: selecting baseline geometry and monitor geometry; matching shot-receiver pairs of the baseline geometry with shot-receiver pairs of the monitor geometry to obtain multiple matching relationships; calculating overall geometry repeatability of each of the multiple matching relationships according to a predetermined calculation formula for multi-trace geometry repeatability, to obtain overall geometry repeatabilities corresponding to the multiple matching relationships; taking the minimum value among the overall geometry repeatabilities corresponding to the multiple matching relationships as overall repeatability metrics between the monitor geometry and the baseline geometry.

Abstract: Systems and methods of performing a seismic survey are described. The system can receive seismic data in a first domain, and transform the seismic data into a tau-p domain. The system can identify a value on an envelope in the tau-p domain, select several values on the tau-p envelope using a threshold, and then generate a masking function. The system can combine the masking function with the tau-p transformed seismic data, and then perform an inverse tau-p transform on the combined seismic data. The system can adjust amplitudes in the inverse tau-p transformed combined seismic data, and identify one or more coherent events corresponding to subsea lithologic formations or hydrocarbon deposits.

Abstract: The present disclosure is related to absolute strength and absolute sensitivity in seismic data. Seismic data from a marine survey can be received. The seismic data can be calibrated based on an absolute strength of a seismic source and an absolute sensitivity of a seismic receiver. The calibrated seismic data can be processed.

Abstract: A method of estimating electromagnetic parameters of a geological structure, comprising: providing controlled source electromagnetic, CSEM, data of the structure, calculating a numerical model representing electromagnetic parameters of the structure and generating simulated CSEM data, discretising the numerical model based on prior knowledge of the structure, defining a functional for minimising the distance between said simulated CSEM data and said CSEM data, wherein the functional comprises a regularisation term which depends on prior knowledge of said structure.

Abstract: The present disclosure describes methods and systems, including computer-implemented methods, computer program products, and computer systems, for generating a velocity model for a subsurface area.

Abstract: System and method for generating discrete dithering sequences DSi for marine seismic sources Si in a marine acquisition system. The method includes determining a number N of the seismic sources Si to be fired; calculating a dithering sequence DSi for each source Si such that when any two consecutive source activation Sk and Sl, where l=k+1, are selected, a combination DSkl of their dithering sequences DSk and DSl is a uniform random low-discrepancy sequence; and driving each source Si with the corresponding dithering sequence DSi to generate blended seismic data.

Abstract: A method is described for predicting fault seal based on a digital seismic image including defining a fault coordinate system locally parallel and perpendicular to the at least one fault surface; extracting seismic amplitudes from a sub-volume surrounding and containing the at least one fault surface and mapping the seismic amplitudes in the fault coordinate system; performing trace fitting of the seismic amplitudes along directions locally perpendicular to the fault surface to separate the fault seismic signal from other seismic energy; comparing the fault seismic signal derived from trace fitting to at least one of natural analogs and synthetic models of seismic response to generate a predicted fault seal; and identify geologic features based on the predicted fault seal. The method may be executed by a computer system.

Abstract: A system, method, and computer program configured to provide an electronic method for seismic time-lapse characterization of an underground formation are provided. The method includes decomposing, with microprocessor executing a predefined set of instructions stored in a memory, baseline and monitor seismic survey data of a formation into a four dimensional Clifford Algebraic form; extracting, via the microprocessor, time delays from a matrix of decomposed sensor measurement vectors generated based on the four dimensional Clifford Algebra form; and determining, via the processor, time strains for the underground formation from differences in the extracted time delays from the matrix before displaying the determined time strains for the underground formation to a user via a monitor or a hard copy printed document. A procedure is also provided to calibrate and refine the static and dynamic models of an underground formation using the results from the seismic time-lapse characterization.

Abstract: A method includes generating a faulted point cloud representing a faulted geological formation including a first fault block having a first surface, a second fault block having a second surface, and a fault formed therebetween and having a fault surface, generating a first fault trace from an intersection of the first surface and the fault surface and a second fault trace from an intersection of the second surface and the fault surface, generating a first fault polygon using the first and second fault traces, generating a center polyline, generating third and fourth fault traces separated from the first and second fault traces, respectively, generating a second fault polygon using the third and fourth fault traces, expanding a first area including the first and third fault traces, expanding a second area including the second and fourth fault traces, and generating an unfaulted point cloud representing an unfaulted geological formation.

Abstract: A method is described for modifying an earth model including receiving an earth model containing one or more surfaces with surface geometries, such that at least two surface depth locations exist for some horizontal positions; perturbing elastic properties within the earth model; and generating a modified earth model by modifying the surface geometries within the earth model while preserving seismic travel times of the earth model such that after an initial user parameterization all updates of the surfaces are done without additional user input. The method may be executed by a computer system.

Abstract: A method, including: obtaining Earth models including velocity, anisotropy, and attenuation reconstructing a source wavefield using the Earth models; reconstructing a receiver wavefield using the Earth models, wherein the reconstructing the source wavefield and the receiver wavefield each include applying an attenuation operator that increases an amplitude of down-going wavefields within an attenuation body and that decreases an amplitude of up-going wavefields within the attenuation body; applying an imaging condition to the source wavefield and receiver wavefield for a plurality of shots; and generating a subsurface image by stacking images for the plurality of shots.

Abstract: A physical voxel, a volumetric testbed, and method for physically simulating a photonic device are described herein. The volumetric testbed comprises a simulation stage and a controller. The simulation stage includes a three-dimensional array of a physical voxels configurable to represent the photonic device operating in response to electromagnetic radiation. The physical voxels includes a field detector to measure a local field response and an impedance adjuster to adjust an impedance to the electromagnetic radiation. The controller is coupled to memory which stores instructions that when executed by one or more processors included in the controller causes the volumetric testbed to perform operations including determining a global field response of the photonic device and adjusting the impedance of the physical voxels to refine a design of the photonic device.

Abstract: The present disclosure describes methods and systems, including computer-implemented methods, computer program products, and computer systems, for modeling angle domain common image gathers (ADCIG) from reverse time migration (RTM). One computer-implemented method includes calculating seismic source and receiver wavefields based on seismic data, calculating characteristic source and receiver wavefields from the seismic source and receiver wavefields, calculating propagation angles for the characteristic source and receiver wavefields, applying a wavefield decomposition algorithm on the characteristic source and receiver wavefields to obtain corresponding directional source and receiver wavefields, the wavefield decomposition algorithm decomposing wavefield amplitude of a wavefield in an angle interval centered on a propagation angle of the wavefield, and forming ADCIG by applying an image condition to the obtained directional source and receiver wavefields.

Abstract: A method is described in which a polyhedral grid representative of seismic data is provided. A polyhedral cell of the polyhedral grid is identified. A polyhedron that encloses the polyhedral cell is created. A region of the polyhedron to remove based on faces of the identified polyhedral cell is identified. The identified region of the polyhedron is removed. The identifying and removing are repeated for a plurality of faces of the identified polyhedral cell. A pressure center of the polyhedral cell is determined.

Abstract: A method for estimating surface waves generates incident, back-scattered, virtual back-scattered and super-virtual back-scattered traces. The stacked super-virtual back-scattered traces are an estimate of the surface waves.

Abstract: A method and apparatus for determining marine seismic source configurations which produce a minimum error after the process of combining the wave fields to eliminate the responses of sources including the source ghost operated at multiple depths, without separating these wave fields, is disclosed. In one embodiment, a method includes simulating, on a computer system, the performing of a seismic survey for one or more source configurations. An error term is calculated for each configuration simulated. Based on the calculated error terms, a configuration having the smallest error among those simulated may be determined.

Abstract: Methods and systems for deriving S-wave velocity information from the low-frequency content of ambient noise are described. The ambient noise can be collected on a dedicated record or on a production record associated with the receivers of a three-dimensional seismic survey. The methods and systems use one of a plurality of analysis models selected based on quality factors of the ambient noise data. The methods and systems analyze the data at a plurality of single frequencies then transform the velocity versus frequency data into velocity versus depth data.

Abstract: Marine survey data resulting from a first signal comprising a signal representing a flat spectral far-field pressure generated by a marine vibrator source swept over a frequency range according to a time function of motion such that acceleration of the marine vibrator source is a flat function in a frequency domain can be used to improve full waveform inversion. For example, full waveform inversion can be performed using the marine survey data received from the first signal and from a second signal generated by an impulsive seismic source to estimate a physical property of a subsurface location.

Abstract: A method for adaptively determining one or more faults from geological survey data includes: (a) generating at least one attribute volume comprising a plurality of attributes from said geological survey data; (b) identifying at least one region of interest on a predetermined cross-section of said at least one attribute volume; (c) adding at least one seed to said at least one region of interest; (d) defining at least one representative area in accordance with said region of interest; (e) starting an initial generation of at least one basic geological object by adapting said at least one seed and/or representative area; (f) selectively determining growth confidence levels for any of said at least one basic geological object based on a realistic geological principles, and mapping said at least one basic geological object with colour-coded data of said growth confidence levels; (g) monitoring a visual representation of said at least one basic geological object during said initial generation; (h) selectively stop

Abstract: Computing systems, computer-readable media, and methods for seismic processing. The method includes receiving seismic data including acquired seismic waveforms that were acquired from a seismic receiver and represent a subterranean area, generating synthetic waveforms based on an initial model of the subterranean area, determining a model error by minimizing a local travel time shift error between one or more of the acquired seismic waveforms and one or more of the synthetic waveforms, and adjusting the initial model based on the model error to generate an adjusted model.

Abstract: A method for estimating formation slowness is provided. The method comprises forward modeling to compute formation slownesses based on a first method for orthorhombic media using stress magnitudes and third-order elastic constants as inputs, and forward modeling to determine formation slownesses analytically based on a second method using stress magnitudes, stress azimuth and third-order elastic constants as inputs. The first method may be based on Tsvankin method and the second method may be based on Christoffel method. The forward modeling may further use well configuration and reference moduli as inputs, and the results from the forward modeling may include formation slownesses, and at least one of vertical slownesses, anisotropic parameters, anellipticity indicators and fast shear azimuth. The method may further comprise assessing quality of the forward modeling based on results output from the forward modeling.