Methods, apparatus, and systems for mapping surface and near surface features and processing artifacts from stacked and processed seismic data are disclosed. In some implementations, a computer system receives a three-dimensional (3D) seismic cube including seismic reflectivity data obtained at a geographical location. The computer system generates a vertical analysis window of the 3D seismic cube. The computer system extracts a second 3D seismic cube from the seismic reflectivity data based on the vertical analysis window. The second 3D seismic cube has multiple vertical amplitude traces associated with the seismic reflectivity data. The computer system generates 3D data comprising multiple frequency traces from the multiple vertical amplitude traces using a domain transform. The computer system generates a two-dimensional (2D) map from the 3D data. The 2D map represents geographical features of the geographical location.

A system for seismic imaging of a subterranean geological formation uses a two-way imaging condition. A seismic signal is emitted into a subterranean formation and recorded at receiver(s). Source and receiver wavefields are decomposed into respective right-down/left-up and left-down/right-up propagating waves. The right-down/left-up and left-down/right-up direction can be defined along the direction emitted from the source or receiver to corresponding direction in two dimensional (2D) case. An imaging condition for generating both a positive-dip structure image and a negative-dip structure image is the inner product of the wavefields. Applying the sample-by-sample multiplication imaging condition to the opposite dip images, the diffraction energy is retained while the reflection energy is significantly attenuated. The diffraction image can be used to detect faults and fractures in subsurface regions.

Systems and methods for seismic imaging of a subterranean geological formation include receiving parameter data representing one or more parameters of a seismic survey, the seismic data specifying an incident angle and an azimuth angle for each trace of the seismic survey; determining a relationship between the incident angle and the azimuth angle for each trace and a location in a spiral coordinate system, and generating a weighting function for applying a weight value to each trace seismic data based on the incident angle and the azimuth angle associated with each trace; and determining a residual moveout value of the seismic data for each location in the spiral coordinate system by applying the weighting function to each; and generating a seismic image representing the residual moveout value of the seismic data for each location in the spiral coordinate system.

The present disclosure describes methods and systems, including computer-implemented methods, computer program products, and computer systems, for generating Angle Domain Common Image Gathers (ADCIGs). One computer-implemented method includes receiving, at a data processing apparatus, a set of seismic data associated with a subsurface region wherein the set of seismic data includes receiver signal data at a plurality of time steps; for each time step in the plurality of time steps: calculating a receiver wavefield based on the receiver signal data at the respective time step; separating a first direction receiver wavefield and a second direction receiver wavefield of the receiver wavefield using Hilbert transformation of the receiver signal data at the respective time step; and applying an optical flow process on the first direction receiver wavefield to calculate wavefield directions; and generating an Angle Domain Common Image Gather (ADCIG) based on the wavefield directions.

Methods arc provided for using sonic tool data to investigate a multi-string wcllbore. The sonic data is processed to obtain indications of phase slowness dispersions for multiple locations in the wellbore. The dispersions are aggregated. The aggregated dispersions are compared with a plurality of cut-off mode templates to identify the presence of cut-off modes or the lack thereof in the aggregated phase slowness dispersions. Features of the multi-string wellbore are identified based on the presence of the cut-off modes or the lack thereof. In another method, the sonic data is processed to obtain indications as a function of depth of at least one of an energy spectrum, a semblance projection, a slowness dispersion projection, an attenuation dispersion projection, and a wavenumber dispersion projection. The indications are inspected to locate a shift at a particular depth indicat- ing a transition in at least oneannulus of the multi-string wellbore.

This disclosure is directed to processes and systems that generate enhanced-resolution seismic images by interpolating sparsely recorded seismic data. Structured dictionary learning is employed to train a set of basis vectors, called “atoms,” and corresponding sparse coefficients on patches of the recorded seismic data. The atoms are constrained to represent the geometric structure of reflection events in the recorded seismic data gather. Linear combinations of the atoms are used to compute interpolated patches over a finer receiver-coordinate grid. The interpolated patches replace the original patches in the recorded seismic data to obtain interpolated seismic data that can be used to generate an image of the subterranean formation.

Implementations described and claimed herein provide systems and methods for isolation detection. In one implementation, recorded data is obtained. The recorded data includes radial acoustic waves transmitted and received using a radial sensor of an acoustic logging tool deployed in a wellbore. Clockwise waves are separated from counterclockwise waves by converting the recorded data from a time domain to a frequency domain. The clockwise waves are shifted into shifted clockwise waves, and the counterclockwise waves are shifted into a shifted counterclockwise waves. A forward wave is generated by combining the shifted clockwise waves, and a reflected wave is generated by combining the shifted counterclockwise waves. One or more isolation regions are identified in the wellbore using the forward wave and the reflected wave.

A system for seismic surveying, method for performing seismic and a non-transitory computer readable medium having instructions stored therein that, when executed by one or more processors, cause the one or more processors to perform a method for performing seismic surveying including emitting seismic waves into a substrate, receiving seismic waves reflected from discontinuities within the substrate, converting the seismic waves into seismic traces, and representing the seismic traces by superimposed multiple tone sinusoidal waves using a parameter estimation. An optimized residual of the modelling is compressed using entropy coding or quantization coding techniques, and the optimized residual and the parameter sets are transmitted to a remote processing station for reconstruction and analysis of the discontinuities.

A system and method for multicomponent noise attenuation of a seismic wavefield is provided. Embodiments may include receiving, at one or more computing devices, seismic data associated with a seismic wavefield over at least one channel of a plurality of channels from one or more seismic sensor stations. Embodiments may further include identifying a noise component on the at least one channel of the plurality of channels and attenuating the noise component on the at least one channel of the plurality of channels based upon, at least in part, the seismic data received from the one or more seismic sensor stations.

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 structure. One computer-implemented method for determining velocity model for a subsurface structure includes generating, by at least one hardware processor, a first velocity model for the subsurface structure by performing a refraction traveltime tomography procedure based on an initial velocity model; and generating, by the at least one hardware processor, a first refined velocity model based on the first velocity model and a structure skeleton model, wherein the structure skeleton model is determined based on reflection seismic data of the subsurface structure.