A method to process vertical seismic profile (VSP) data includes receiving VSP data, migrating the VSP data output using an initial velocity model to produce migrated depth values associated with the respective receivers, sorting and collecting the migrated depth values corresponding to each receiver to produce a migrated common receiver gather (CRG) associated with each receiver, stacking the migrated depth values of the CRGs corresponding to respective fixed lateral positions in an image volume to produce a common image gather (CIG) associated with each lateral position, and generating a semblance panel having the stacked depth migration values plotted as contours on a first axis for velocity ratio (vr), which is based on migration velocity and true velocity) and a second axis for true depth (Zt). The method further includes updating the initial velocity model based on a plurality of data points selected from the semblance panel to provide an updated velocity model.

Provided is a method of first arrival picking of multi-channel seismic survey data considering sound source-receiver array that can increase the reliability of a first arrival selected from land seismic survey data or marine seismic survey data that includes background noise. Further, provided is a method of first arrival picking of multi-channel seismic survey data considering source-receiver array, which can improve the reliability of a first arrival or a micro earthquake occurrence location selected from measurement data of a micro earthquake seismic survey.

The disclosure provides systems and methods to enhance pre-stack data for seismic data analysis by: sorting the reflection seismic data acquired from cross-spread gathers into sets of data sections; performing data enhancement on the sets of data sections to generate enhanced traces by: (i) applying forward normal-moveout (NMO) corrections such that arrival times of primary reflection events become more flat, (ii) estimating beamforming parameters including a nonlinear traveltime surface and a summation aperture, (iii) generating enhanced traces that combine contributions from original traces in the sets of data sections, and (iv) applying inverse NMO corrections to the enhanced traces such that temporal rearrangements due to the forward NMO corrections are undone.

Methods and systems including computer programs encoded on a computer storage medium, for utilizing equivalent linear velocity for first arrival picking of seismic refraction. In one aspect, a method includes receiving data for the shot gather record, generating a diving wave equation curve for a particular parameter pair of multiple parameter pairs, and integrating the shot gather record data corresponding to the diving wave equation curve over a selected range of offsets of the shot gather to generate an equivalent linear velocity value for the particular parameter pair and the shot gather record data, selecting, from the equivalent linear velocity values for the plurality of parameter pairs, a greatest equivalent linear velocity value of the equivalent linear velocity values, the greatest equivalent linear velocity value corresponding to a first-arrival parameter pair, and determining, using the first-arrival parameter pair, a set of first-arrival onsets for the selected sub-range of offsets.

Techniques are described for generating seismic images based on pressure-shear (PS) wave information. Sensor data is generated by through seismic probing of an underground environment. The sensor data can include pressure (P) wave data. The sensor data is analyzed to determine PS wave data present in the sensor data. A CFP gathers spectrum is generated using the P wave velocity. An optimal curve through the CFP gathers spectrum is determined, and PS image(s) of the underground environment are generated by scanning along the optimal curve. The PS image(s) can be provided for presentation through interface(s). The generated PS wave images are correlated with P wave images, and can be plotted on the same coordinate system as P wave images.

A method and apparatus for estimating RMO error, including obtaining input data comprising a domain of picking locations; running a plurality of residual moveout (RMO) error-picking algorithms with the input data; for each of the plurality of RMO error-picking algorithms, flattening gathers based on the respective RMO error-picking algorithms to generate a resultant error pick; comparing the resultant error picks from the plurality of RMO error-picking algorithms at each picking location in the domain of picking locations; and assembling a set of final RMO error picks from the resultant error picks from the plurality of RMO error-picking algorithms at each picking location.

A system and a computer-implemented include the following. A field dataset of seismic waves is received that is obtained by receivers during a drilling period from a drilling operation at a target well. The drilling period includes drilling and non-drilling phases. The field dataset is analyzed to determine locations of seismic waves. A reconstructed wavefield is determined by applying a passive seismic imaging condition over time and based on locations of the receivers. Using the reconstructed wavefield, a time series is computed for the seismic waves, and a time-frequency transform is applied on the time series. Sources and locations of tube waves resulting from acoustic signatures of the drill bit the drilling phases are determined. Sources and locations of the body waves caused by the tube waves are determined. A petrophysical model of the target well is updated in real-time based on the analyzing and the waves.

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.

A system provides seismic images of the subsurface by enhancing pre-stack seismic data. The system obtains seismic data comprising a plurality of seismic traces that are generated by measuring reflections of seismic waves emitted into a geological formation. The system sorts seismic data into at least one multidimensional gather comprising a data domain. The system determines local kinematical attributes of a seismic trace. The system forms an ensemble of seismic traces, each representing a reference point. The system applies local moveout corrections to each seismic trace of the ensemble. The system applies residual statics and phase corrections for each seismic trace that is corrected by the local moveout corrections. The system sums the seismic traces of the ensemble to obtain an output seismic trace having an increased signal-to-noise ratio (SNR) relative to the seismic trace that represents the reference point for the ensemble of seismic traces.

A sonic logging method is provided that transmits acoustic signals using a high order acoustic source and processes waveform data to identify a set of arrival events and time picks by automatic and/or manual methods. Ray tracing inversion is carried out for each arrival event over a number of possible raypath types that include at least one polarized shear raypath type to determine two-dimensional reflector positions and predicted inclination angles of the arrival event for the possible raypath types. One or more three-dimensional slowness-time coherence representations are generated for the arrival event and raypath type(s) and evaluated to determine azimuth, orientation and raypath type of a corresponding reflector. The method outputs a three-dimensional position and orientation for at least one reflector. The information derived from the method can be conveyed in various displays and plots and structured formats for reservoir understanding and also output for use in reservoir analysis and other applications.