Abstract: An induced earthquake evaluation method for hydraulic fracturing activated faults includes obtaining an induced earthquake evaluation unit, cumulative injection equivalent energy, induced earthquake probability of fault type, induced earthquake probability of fault distance, hydraulic fracturing fluid diffusion capacity in fractured formation, new effective fault stress after fracturing, formation fluid pressure change rate and cumulative released equivalent energy. The probability of induced earthquake by hydraulic fracturing can be obtained. The induced earthquake possibility of each evaluation unit or single well under different stages of hydraulic fracturing, different construction injection methods and production conditions can be quantitatively evaluated. The method provides a quantitative result that can provide data support for optimizing hydraulic fracturing and reducing induced earthquake hazards.

Abstract: Provided herein are systems and methods for generating reservoir models including the SOC nature of the Earth's crust. The methods employ seismic emission tomography (SET) to generate three dimensional models of a formation providing permeability without the need for traditional reservoir modeling techniques and allowing for the identification of naturally-occurring permeability pathways that provide accurate and precise locations for the efficient recovery of hydrocarbons or other fluids.

Abstract: Embodiments relate to data acquisition units or nodes and more specifically to seismic data acquisition units or nodes for use in data gathering for ambient noise tomography (ANT). Some embodiments relate to a method for data acquisition, and systems employing one or more data acquisition units. Some embodiments relate to systems comprising one or more satellites in communication with one or more data acquisition units for communication to a remote server, for remote storage, and processing for creating sub-surface tomography images accessible to client devices.

Abstract: An earthquake event classification method using an attention-based neural network includes: preprocessing input earthquake data by centering; extracting a feature map by nonlinearly converting the preprocessed earthquake data through a plurality of convolution layers having three or more layers; measuring importance of a learned feature of the nonlinear-converted earthquake data based on an attention technique in which interdependence of channels of the feature map is modeled; correcting a feature value of the measured importance value through element-wise multiply with the learned feature map; performing down-sampling through max-pooling based on the feature value; and classifying an earthquake event by regularizing the down-sampled feature value. Accordingly, main core features inherent in many/complex data are extracted through attention-based deep learning to overcome the limitations of the existing micro earthquake detection technology, thereby enabling earthquake detection even in low SNR environments.

Abstract: A method and system for picking first-break times for a seismic dataset are disclosed. The method includes generating a pre-processed seismic dataset and an initial refraction velocity model from the pre-stack seismic dataset and generating a first-break energy-enhanced seismic dataset using nonlinear beamforming applied to the pre-processed seismic dataset and the initial refraction velocity model. The methods further include estimating a refined refraction velocity model from the first-break energy-enhanced seismic dataset, and generating a post-processed seismic dataset from the refined refraction velocity model and first-break energy-enhanced seismic dataset. The methods still further include, for each pre-stack trace, determining a first-break time from the post-processed seismic dataset and the refined refraction velocity model.

Abstract: One embodiment of the present invention relates to a method for performing a vehicle image reconstruction by a sensing vehicle (SV) in a wireless communication system, the method comprising: receiving a plurality of stepped-frequency-continuous-wave (SFCW) from target vehicle (TV); receiving signature waveforms in a different frequency range for the plurality of SFCWs; performing synchronization by using phase-difference-of-arrival (PDoA) based on the signature waveforms; reconstructing one or more virtual images of the TV; and deriving a real image from the one of more Virtual Image.

Abstract: A graphical user interface includes GUI elements configured for defining discretized base geometry data for a model of a physical system, receiving a first input representing a user instruction to add a perfectly matched layer to the model, receiving a second input representing the user selection of boundaries that define a base geometry, and receiving a third input representing extra geometry meshing instructions. Extra geometry line segment data is discretized representing an outward direction of a PML from the boundary according to the extra geometry meshing instructions. Weak form expressions representing a wave-related phenomena are formed based on received PML settings and physics settings parameterized using discretized base geometry data and discretized extra geometry data. Matrix data are generated based on the formed weak form expressions. A solution to a simulation of the wave-related phenomena of the model is generated based on the formed weak form expressions.

Abstract: Embodiments herein relate to a computer-implemented technique that includes generating, in a first portion of a graphical user interface (GUI), a first graphical element related to reflection seismic data of an area of interest. The technique further includes generating, in a second portion of the GUI, a second graphical element related to well structural data of the area of interest. The technique further includes generating, in a third portion of the GUI, a third graphical element that is based on the reflection seismic data and the well structural data. In embodiments, an alteration of the first graphical element or the second graphical element results in a concurrent alteration of the third graphical element. Other embodiments may be described or claimed.

Abstract: A method for offset well analysis includes receiving offset well data collected from an offset well, the offset well data including data representing a trajectory of an offset well, receiving subject well data comprising a trajectory of at least a portion of a subject well, partitioning the trajectory of the offset well into a plurality of offset well segments, partitioning the trajectory of the subject well into a plurality of subject well segments, determining a distance between at least some of the plurality of offset well segments and at least some of the plurality of subject well segments, selecting the offset well based in part on the distance, and performing an offset well analysis using the offset well and the subject well.

Abstract: Methods and systems for determining an image of a subterranean region of interest are disclosed. The method includes obtaining a seismic dataset and a geological dip model for the subterranean region of interest and determining a set of input seismic gathers from the seismic dataset. The method further includes determining a central seismic gather and a set of neighboring seismic gathers in a vicinity of the central seismic gather from the set of seismic gathers, determining a set of dip-corrected neighboring seismic gathers based, at least in part, on the set of neighboring seismic gathers and a geological dip from the geological dip model, and determining a noise-attenuated central seismic gather by combining the dip-corrected neighboring seismic gathers and the central seismic gather. The method still further includes forming the image of the subterranean region of interest based, at least in part, on the noise-attenuated central seismic gather.

Abstract: This disclosure relates to geophysical exploration and seismic imaging, and more particularly to a seismic imaging method, system, and device based on pre-stack high-angle fast Fourier transform (FFT). The method includes: acquiring seismic data acquired during seismic exploration; extracting a common shot point gather from the seismic data followed by conversion into a frequency wavenumber domain common offset gather; calculating wave propagation angles; dividing an imaging region into a first region and a second region; solving constant coefficients of the first region and the second region; performing frequency-division layer-by-layer wavefield continuation on a frequency-wave number domain common offset gather to obtain imaging results at different depths and frequencies; subjecting the imaging results to integration followed by transformation to a spatial domain to obtain common offset imaging profiles; and subjecting the common offset imaging profiles to superposition obtain final imaging results.

Abstract: Described herein are systems and methods of selecting treatment parameters values for treating skin lesions. A device may establish a treatment parameter selection model using a training dataset. The training dataset may include a plurality of examples. Each example may include a sample image of an example skin lesion to which a treatment is administered using an applicator. Each example may include a first label indicating success or failure of the treatment. Each example may include a second label corresponding to treatment parameters defining the treatment. The device may identify an input image. The device may determine that the input image corresponds to a skin lesion based on visual characteristics of the input image. The device may apply the treatment parameter selection model to the input image to output a recommended treatment to apply. The device may store an association between the input image and the recommended treatment.

Abstract: A method for extracting a downgoing wavelet and attenuation parameters from VSP data, comprising: performing upgoing and downgoing P-waves separation processing on VSP data to obtain downgoing P-wave data; performing a FFT on seismic data with a preset time window length and cut from the downgoing P-wave data to obtain FFT transformed downgoing P-wave data and a multi-trace downgoing P-wave log spectrum; subtracting a downgoing wavelet log spectrum from the multi-trace downgoing P-wave log spectrum to obtain a wavelet-corrected multi-trace downgoing P-wave log spectrum; performing a correction and an inverse FFT on the FFT transformed downgoing P-wave data to obtain a downgoing wavelet; and obtaining attenuation parameters based on P-wave first arrival time and the parameters of the wavelet-corrected multi-trace downgoing P-wave log spectrum. Also provided are an apparatus for extracting a downgoing wavelet and attenuation parameters from VSP data and a computer device.

Abstract: A method is claimed for automatically transforming sonic well logs from a depth domain to a seismic two-way travel-time domain. The method includes obtaining a training well with a measured sonic well log in the depth domain and a borehole seismic dataset in the depth domain and obtaining an application well with only a measured sonic well log in the depth domain. The method further includes training a network to predict a transformed sonic well log for the training well based, at least in part, on the measured sonic well log and the borehole seismic dataset in the training well, and predicting with the network, the transformed sonic well log in the application well.

Abstract: Methods and systems are disclosed for updating a seismic velocity model of a subterranean region of interest. The method includes receiving an observed seismic dataset and a seismic velocity model, and generating a simulated seismic dataset based on the seismic velocity model and the geometry of the observed seismic dataset, wherein each dataset is composed of a plurality of seismic traces. The method further includes determining a transformed observed seismic dataset and a transformed simulated seismic dataset by determining the instantaneous frequency of at least one member of the plurality of observed seismic traces; and at least one member of the plurality of simulated seismic traces. The method still further includes forming an objective function based on the transformed observed seismic dataset and the transformed simulated seismic dataset and determining an updated seismic velocity model based on an extremum of the objective function.

Abstract: A computer-implemented method may include obtaining seismic data acquired in a time-domain for a subterranean region of interest. The method may further include obtaining a property model for the subterranean region of interest. The method may further include determining one or more time shifts using a segment dynamic image warping function based on the seismic data and the property model. The method may further include determining an adjoint source operator using the derived time shift and one-way wave equation. The method may further include updating the property model using a gradient solver in a data-domain reflection traveltime inversion. The method may further include outputting the updated property model for the subterranean region of interest. The method may further include generating a seismic image for the subterranean region of interest using the updated property model.

Abstract: A method for verticalizing recorded seismic data, the method including recording first data with a particle motion sensor, wherein the particle motion sensor is located on a streamer, and the particle motion sensor is configured to be insensitive to a direct current, recording second data with a gravity motion sensor, wherein the gravity motion sensor is also located on the stream, and the gravity motion sensor is configured to be sensitive to the direct current and temporally synchronous to the particle motion sensor, selecting a cost function that associates corresponding values of the first data and the second data, determining a misalignment angle from maximizing the cost function, wherein the misalignment angle describes a misalignment between corresponding axes of the particle motion sensor and the gravity motion sensor, and correcting seismic data recorded by the particle motion sensor based on the misalignment angle so that the corrected seismic data is verticalized with regard to gravity.

Abstract: A method for picking first breaks on a synthetic seismic dataset for a full wavefield travel-time inversion is provided. This method includes obtaining a synthetic seismic dataset and for each synthetic trace, determining a plurality of synthetic trace amplitude maxima and minima, determining a modified energy ratio trace, and forming a trace mask based at least in part, on an amplitude of the synthetic trace and on an amplitude of the modified energy ratio trace. The method further includes determining for each synthetic trace, a positive estimated first break based on the plurality of synthetic trace amplitude maxima and the trace mask and a negative estimated first bread based on the plurality of synthetic trace amplitude minima and the trace mask. The method concludes with determining a predicted first break for each synthetic trace from the positive estimate first break and the negative estimate first break.

Abstract: To obtain a global optimal navigation track, a contour line matching method based on sliding window data backtracking includes the steps of determining sliding window parameters according to the calculation performance of a real-time multi-task operating system and aided navigation precision requirements, constructing a sliding window data backtracking framework by using historical physical field value matching data, obtaining a rotation transformation matrix from an indication track point set to a closest reference point set by adopting a matrix eigenvalue and eigenvector decomposition method, and moving a sliding window and performing forward and reverse cyclic matching to achieve a global track constraint, thereby improving the matching precision and robustness.

Abstract: The present invention discloses a three-dimensional in-situ characterization method for heterogeneity in generating and reserving performances of shale. The method includes the following steps: establishing a logging in-situ interpretation model of generating and reserving parameters based on lithofacies-lithofacies-well coupling, and completing single-well interpretation; establishing a 3D seismic in-situ interpretation model of generating and reserving parameters by using well-seismic coupling; establishing a spatial in-situ framework of a layer group based on lithofacies-well-seismic coupling, and establishing a spatial distribution trend framework of small layers of a shale formation by using 3D visualized comparison of a vertical well; and implementing 3D in-situ accurate characterization of shale generating and reserving performance parameters by using lithofacies-well-seismic coupling based on the establishment of the seismic-lithofacies dual-control parameter field.

Abstract: Methods and systems for determining a spectral ratio log using a time domain seismic image and a seismic velocity model are disclosed. The method includes determining a first mono-spectral seismic image and a second mono-spectral seismic image from the time domain seismic image. The method further includes determining a time domain spectral ratio image from the first mono-spectral seismic image and the second mono-spectral seismic image and transforming the time domain spectral ratio image into a depth domain spectral ratio image using the seismic velocity model. The method still further includes defining a wellbore path through the depth domain spectral ratio image and determining a spectral ratio log along the wellbore path from the depth domain spectral ratio.

Abstract: A gravity inversion method and system based on a meshfree method.

Abstract: Using machine learning for sedimentary facies prediction by using one or more logs acquired in a borehole. This includes performing a petrophysical clustering of borehole depths wherein the depths of the borehole are gathered into clusters based on similarities in the one or more logs. Also performed is a log inclusion optimization, including a selection of one or more parameters of the petrophysical clustering, wherein the one or more parameters include a number and/or type of considered logs among the one or more logs and/or a clustering method. Also performed is a classification of the clusters into core depositional facies using one or more predetermined rules.

Abstract: A method of analysing seismic data to detect possible hydrocarbons includes determining a set of data tiles from a seismic data cube of seismic data and testing each data tile in the set of data tiles to determine whether it corresponds to a possible fluid contact.

Abstract: A method is described for inverting seismic data including obtaining well logs representative of subsurface volumes of interest; generating an amplitude variation with angle (AVA) database from the well logs by seismic modeling, wherein the seismic modeling is performed a plurality of times for all combinations of fluid substitutions of brine, oil, and gas and low porosity, mid-porosity, and high porosity; generating a trained AVA model using the AVA database; obtaining a seismic dataset; calibrating the seismic dataset; computing seismic attributes for the calibrated seismic dataset using statistics for AVA classification; and generating direct hydrocarbon indicators as a function of position in the subsurface volume of interest by applying the trained AVA model to the seismic attributes. The method is executed by a computer system.

Abstract: Disclosed are a method and apparatus for estimating S-wave velocities by learning well logs, whereby the method includes a model formation step of forming an S-wave estimation model to output S-wave velocities corresponding to measured depth when the well logs are input based on train data sets including train data having values of multiple factors included in the well logs, the values being arranged corresponding to measured depth, and label data having S-wave velocities corresponding to measured depth as answers, and an S-wave velocity estimation step of inputting unseen data having values of multiple factors included in well logs acquired from a well at which S-wave velocities are to be estimated, the values being arranged corresponding to measured depth, to the S-wave estimation model to estimate S-wave velocities corresponding to measured depth.

Abstract: A stimulation includes an injection of a volume of fluid into a formation. A method includes obtaining a mechanical earth model of the formation, modeling a hydraulic fracture growth pattern in the formation from a stimulation of the formation, determining an increase in pressure in the formation resulting from the stimulation, and predicting whether a seismic event will occur in the formation based on the increase in pressure.

Abstract: Systems, computer readable, and methods concern receiving seismic data representing a subsurface volume. The method also includes determining, for the seismic data, analysis coordinates as a function of time. One or more of the analysis coordinates may vary in position over time. The method includes performing at least one of an interpolation or regularization process on the seismic data based at least partially on the analysis coordinates. The method also includes outputting a result of the at least one of the interpolation or regularization process.

Abstract: Provided is an autonomous ship navigation apparatus including an acquisition unit configured to acquire a surrounding environment image, marine information, and navigation information, a map generation unit configured to generate a grid map by displaying topography, a host ship, and an obstacle corresponding to the marine information and the navigation information in the surrounding environment image, and a sailing method determination unit configured to determine a sailing method of a ship through deep reinforcement learning based on the grid map, the marine information, and the navigation information.

Abstract: Methods and systems for forming a three-dimensional (“3D”) seismic image of a subterranean region of interest is disclosed. The method includes obtaining a seismic dataset a seismic trace for each of a plurality of pairs of one source and one receiver location and obtaining a 3D travel-time cube for each source location and each receiver location. The method further includes dividing the seismic dataset into a plurality of seismic subsets composed of set of source locations, set of receiver locations a seismic trace for each pair of source and receiver location and the 3D travel-time cube for each source for each receiver location. The method still further includes transmitting, to a random-access memory block of a computer processing unit the seismic subset, and forming a seismic partial image based on the seismic subset, and determining the 3D seismic image based on a combination of the seismic partial images.

Abstract: A method of using a fractalization protocol to control the operation or travel path of a vehicle during travel or flight, includes a plurality of sensors that detect the occurrence of an event or travel path deviation. A master fractal controller initiates a space-variant fractalization protocol in order to collect the input data related to the detected event. In response to the input data, if the master space-variant fractalization protocol detects a deficiency in data resolution of the collected input data it identifies the slave controllers that are relevant to compensate for such deficiency. The master space-variant fractalization protocol then initiates slave fractals that correspond to the identified slave controllers for collecting additional input data and that define adjustable slave fractalization protocols. The space-variant fractalization protocol then causes the slave fractalization protocols to collect the additional input data.

Abstract: Some implementations of the present disclosure provide a method that include: accessing a set of seismic traces from a grid of locations inside an geo-exploration area, each seismic trace records seismic reflections from underneath the geo-exploration area at a location of the grid; accessing an input indicating a surface in the set of seismic traces; extracting a plurality of wavelets from the set of seismic traces, each wavelet covering an adjustable length around the surface; determining a reference wavelet for each wavelet of a corresponding adjustable length; and quantifying a quality of the surface based on correlating the plurality of wavelets with each reference wavelet of the corresponding adjustable length.

Abstract: Systems and methods of placing wells in a hydrocarbon field based on seismic attributes and quality indicators associated with a subterranean formation of the hydrocarbon field can include receiving seismic attributes representing the subterranean formation and seismic data quality indicators. A cutoff is generated for each seismic attribute and seismic data quality indicator. A weight is assigned to each seismic attribute and seismic data quality indicator. The weighted seismic attributes and data quality indicators are aggregated for each location in the hydrocarbon field. A risk ranking is assigned based on the weighted seismic attributes and data quality indicators associated with each location in the hydrocarbon field based on the cutoffs. A map is generated with each location on the surface of the subterranean formation color-coded based on its assigned risk ranking.

Abstract: A surface wave prospecting method for jointly extracting Rayleigh wave frequency dispersion characteristics in a seismoelectric field. A surface wave prospecting method includes following steps of: acquiring jointly acquired data, where the jointly acquired data includes seismic wave data and electric field data; carrying out jointly imaging processing on jointly acquired data to obtain a superposed frequency dispersion spectrum; carrying out extraction processing on superposed frequency dispersion spectrum to obtain a frequency dispersion curve, outperforming inversion processing on frequency dispersion curve to obtain a stratum structure profile. As seismic wave data and electric field data are adopted to carry out combined imaging processing to obtain superposed frequency dispersion spectrum, multi-mode frequency dispersion curve is extracted, multiplicity of solutions of inversion is greatly reduced during inversion, precision and stability of surface wave prospecting are greatly improved.

Abstract: A method includes receiving seismic data for a geologic region of the Earth; building a velocity model of the geologic region of the Earth; selecting at least one mode of multiple and corresponding travel time data from a data storage where the travel time data correspond to at least one complex ray signature in the geologic region of the Earth and are based at least in part on the velocity model; performing migration on the seismic data using at least the selected travel time data to generate processed seismic data; and rendering an image of the geologic region of the Earth to a display where the image includes at least a multiple image.

Abstract: A method includes receiving a seismic data volume comprising seismic information of subterranean formations and receiving a set of seismic traces of the seismic data volume. The method also includes, determining, along each seismic trace of the set of seismic traces, a set of seed points comprising minimum or maximum onsets. Further, the method includes sorting the set of seed points into a sorted set of seed points by absolute amplitude values of the set of seed points. Furthermore, the method includes generating a horizon representation of every seismic event in the seismic data volume by automatically tracking horizons throughout an entirety of the seismic data volume from the sorted set of seed points in an order of the absolute amplitude values of the sorted set of seed points. Additionally, the method includes generating a graphical user interface that includes the horizon representation for display on a display device.

Abstract: Systems and methods include a computer-implemented method includes concurrently outputting, by a computing device to a display of the computing device, a graphical time-domain interpretation of seismic data, a graphical velocity model related to the seismic data, and a graphical depth-domain interpretation of the seismic data. The method may further include identifying, by the computing device, a first alteration to one of the time-domain interpretation, the velocity model, and the depth-domain interpretation. The method may further include identifying, by the computing device based on the first alteration, a second alteration to another of the time-domain interpretation, the velocity model, and the depth-domain interpretation. The method may further include updating, by the computing device based on the first alteration and the second alteration, at least two of the graphical time-domain interpretation, the graphical velocity model, and the graphical depth-domain interpretation.

Abstract: In examples, threads of a schedulable unit (e.g., a warp or wavefront) of a parallel processor may be used to sample visibility of pixels with respect to one or more light sources. The threads may receive the results of the sampling performed by other threads in the schedulable unit to compute a value that indicates whether a region corresponds to a penumbra (e.g., using a wave intrinsic function). Each thread may correspond to a respective pixel and the region may correspond to the pixels of the schedulable unit. A frame may be divided into the regions with each region corresponding to a respective schedulable unit. In denoising ray-traced shadow information, the values for the regions may be used to avoid applying a denoising filter to pixels of regions that are outside of a penumbra while applying the denoising filter to pixels of regions that are within a penumbra.

Abstract: Methods of oil and gas exploration that may include: obtaining wavefield data representing recordings from a propagating wavefield through a geophysical volume; obtaining at least one reference digital image of a portion or all of the geophysical volume generated from the recorded wavefield data, wherein the reference image may have a reference sampling ratio and a reference image quality value; selecting a holographic computational method of imaging the wavefield data; selecting a data subset from the wavefield data based on one or more parameters selected from the group consisting of field sampling, imaging sampling, and image quality; decimating the data subset, wherein the decimated data subset may represent a sampling ratio less than the reference sampling ratio; and generating a new digital image based on the selected holographic computational method of imaging, the data subset, and parameters corresponding to the data sub set.

Abstract: The present disclosure relates to a method and system for monitoring a wellbore object using a reflected pressure signal. The method discloses providing at least one pump for performing hydraulic fracturing or a source of hydraulic pulse so that pressure signal propagates along the wellbore and reflects from the borehole objects; providing pressure sensor at wellhead; preprocessing of registered reflected pressure signal and pump noise; transforming the registered reflected pressure signal and pump noise from the frequency domain into time-frequency representation with Short Time Fourier Transform (STFT), computing a pump noise mask; applying the pump noise mask to the STFT representation to obtain a filtered reflected pressure signal; processing of the filtered reflected pressure signal for determining the reflection time from the downhole object, calculating the depth of the downhole object from reflected pressure signal by multiplying of the reflection time by the pressure signal propagation velocity.

Abstract: A system and method are provided for automatically correlating geologic tops. The system receives well logs from different well bores and each of the picks is added to a priority queue ordered by each pick's quality measure. User selected picks are assigned the highest level of quality measure. The system performs correlation by selecting a window of well log data about a pick selected from the top of the priority queue and then finding the best optimal match with a corresponding window in a neighboring wellbore.

Abstract: Seismic data are obtained by recording simultaneously in seismic streamer, acquired by activating approximately simultaneously two or more seismic sources towed at two positions in the vicinity of seismic streamers. A residual is updated iteratively for an inversion solution for the activations of the two or more seismic sources. The iterative updating of the residuals utilizes a sequence of overlapping temporal windows containing reflection events and utilizes normal moveout corrections based on largest reflection events in each temporal window. A final updated residual is added to a final updated model result.

Abstract: A method and apparatus for seismic analysis include obtaining an initial geophysical model and seismic data for a subsurface region; producing a subsurface image of the subsurface region with the seismic data and the geophysical model; generating a map of one or more geologic features of the subsurface region by automatically interpreting the subsurface image; and iteratively updating the geophysical model, subsurface image, and map of geologic features by: building an updated geophysical model based on the geophysical model of a prior iteration constrained by one or more geologic features from the prior iteration; imaging the seismic data with the updated geophysical model to produce an updated subsurface image; and automatically interpreting the updated subsurface image to generate an updated map of geologic features.

Abstract: A method and system for estimating a full elastic tensor. The method may comprise taking a measurement for compressional wave sonic data and cross-dipole shear data with a sonic logging tool at a first location as cross-dipole data, processing the compressional wave sonic data to produce a compressional wave slowness (P), and processing the cross-dipole shear data to produce a fast horizontal polarized shear wave slowness (SH) and a slow quazi-vertical shear wave slowness (qSV) as a function of depth. The method may further comprise setting an initial guess for at least five constants of the full elastic tensor for Vertical Transversely Isotropy (VTI) symmetry, determining a modeled slowness surfaces from the full elastic tensor, and comparing the modeled slowness surfaces with measured values of the P, the SH, and the qSV. The method may be performed by a system comprising a sonic logging tool and an information handling system.

Abstract: Systems, methods, and apparatuses for generating a subsurface image using diffraction energy information are disclosed. The systems, methods, and apparatuses may include converting a shot gather into one or more plane-wave gather using a Radon transform. The plane-wave gathers may be extrapolated into source-side wavefields and receiver-side wavefields and further generate a pseudo dip-angle gather. The diffraction energy information may be extracted from the pseudo dip-angle gather, and an image containing subsurface features may be generated from the extracted diffraction energy information. The receiver-side wavefields may be decomposed using a recursive Radon transform.

Abstract: A hydrophone array tool as described herein is configured to locate leakages throughout a borehole with improved accuracy using acoustic beamforming techniques with acoustic velocity estimation. An acoustic beamforming processor generates an initial beamforming map and corresponding initial estimated leakage location using acoustic measurements throughout the borehole. The acoustic beamforming processor generates additional beamforming maps at the initial estimated leakage location, each additional beamforming map corresponding to an acoustic velocity within a range of anticipated acoustic velocities. An acoustic velocity estimator determines an acoustic velocity corresponding to a beamforming map with spatial statistics that indicate a most prominent leakage location. The acoustic beamforming processor updates the leakage location according to this beamforming map for improved accuracy.

Abstract: A seismic time-frequency analysis method based on generalized Chirplet transform with time-synchronized extraction, which has higher level of energy aggregation in the time direction and can better describe and characterize the local characteristics of seismic signals, and is applicable to the time-frequency characteristic representation of both harmonic signals and pulse signals, comprising the steps of processing generalized Chirplet transform with time-synchronized extraction for each seismic signal to obtain a time spectrum by: carrying out generalized Chirplet transform, calculating group delay operator and carrying out time-synchronized extraction on seismic signals, thereby the boundary and heterogeneity structure of the rock slice are more accurately and clearly shown and subsequence seismic analysis and interpretation are facilitated.

Abstract: A method can include acquiring imagery of an exposed surface of the Earth; generating a multi-dimensional model based at least in part on the imagery; generating synthetic seismic data utilizing the multi-dimensional model; acquiring seismic data of a subsurface region of the Earth; performing a search that matches a portion of the acquired seismic data and a portion of the synthetic seismic data; and characterizing the subsurface region of the Earth based at least in part on the portion of the synthetic seismic data.

Abstract: A system and method can be used for to calibrating time-lapse seismic volumes by cross-migration rescaling and reorientation for use in determining optimal wellbore placement or production in a subsurface environment. Certain aspects include methods for cross-migration of data sets processed using different migration techniques. Pre-processing of the data sets, optimization of rescaling and reorientation, and identification of adjustment parameters associated with minimum global error can be used to achieve a time-dependent formation data set that addresses error in all input data sets.

Abstract: Methods and devices for seismic exploration of an underground structure apply W2-based full-wave inversion to transformed synthetic and seismic data. Data transformation ensures that the synthetic and seismic data are positive definite and have the same mass using an adaptive normalization. This approach yields superior results particularly when the underground structure includes salt bodies.