A method for enhanced dispersion analysis begins with obtaining a plurality of measured waveforms, for example from two or more receivers of an acoustic logging tool placed in a borehole. The measured waveforms are divided into common gathers, and waveforms of each common gather are enhanced. The enhancement begins by calculating a travel time curve for a selected target mode of the common gather waveforms. Using the travel time curve, waveforms of the selected target mode are aligned to have zero apparent slowness. The aligned waveforms are filtered to suppress non-target mode waves. The aligned waveforms are then enhanced, and used to generate an enhanced dispersion curve of the selected target mode.

Systems and methods that include receiving reservoir data of a hydrocarbon reservoir, receive an indication related to selection of a wavefield propagator, application of the wavefield propagator utilizing Fourier Finite Transforms and Finite Differences to model a wavefield associated with a Tilted Orthorhombic media representative of a region of a subsurface comprising the hydrocarbon reservoir, and processing the reservoir data in conjunction the wavefield propagator to generate an output for use with seismic exploration above a region of a subsurface comprising the hydrocarbon reservoir and containing structural or stratigraphic features conducive to a presence, migration, or accumulation of hydrocarbons.

A method for estimating sonic slowness comprising: obtaining (700) a plurality of sonic waveforms are received by a plurality of receivers of a logging tool after emission of a source sonic wave by a transmitter, obtaining (710) slowness models of the subterranean formation, a slowness model being defined by a at least one cell of constant slowness for at least one wave energy mode, computing (720), for each slowness model, a set of candidate travel times, a candidate travel time of a set of candidate travel times being computed for a wave energy mode and a position of a receiver of the plurality of receivers, computing (730) a relevance indicator for each set of candidate travel times based on the recorded sonic waveforms; searching (740) a match between the sets of candidate travel times and the recorded sonic waveforms by searching a relevance indicator which is optimum, computing (750) a sonic slowness estimate for the subterranean formation from a set of candidate travel times for which the relevance indicator is optimum.

A method for seismic data processing can include obtaining seismic data acquired based upon trigger times and not based upon positions of triggered source elements. The seismic data can include near-continuously recorded seismic data in split records. The split records can be spliced together into a single near-continuous record to produce a trace with seismic data from a single acquired line. The seismic data can be processed by performing a spatial shift for each of a number of time samples to correct for motion of a number of seismic receivers.

Methods and systems for identifying near-surface heterogeneities in a subterranean formation using surface seismic arrays can include: recording raw seismic data using sensors at ground surface; applying a band bass filter to the raw seismic data using a central frequency; picking a phase arrival time for the filtered data; generating an initial starting phase velocity model for tomographic inversion from the raw seismic data; applying tomographic inversion to the filtered data to generate a dispersion map associated at the central frequency; repeating the applying a band bass filter, picking a phase arrival time, generating an initial starting velocity model, and applying tomographic inversion steps for each of a set of central frequencies; and generating a three-dimensional dispersion volume representing near-surface conditions in the subterranean formation by combining the dispersion maps.

Methods, systems, and computer program products for characterizing materials in a wellbore having multiple casing strings uses well completion data and instantaneous frequency, instantaneous phase, and/or amplitude attributes, including waveform amplitude or instantaneous amplitude, of an acoustic waveform to determine material densities, acoustic velocities and acoustic travel distances for the materials between the various stages of casings.

A method is described for image-domain full waveform inversion. The method may include receiving, at a computer processor, a seismic dataset representative of the subsurface volume of interest and an initial earth model; performing, via the computer processor, an image domain full waveform inversion to generate an updated earth model; and performing, via the computer processor, seismic imaging of the seismic dataset using the updated earth model to generate a seismic image. The method may be executed by a computer system.

A method for enhanced dispersion analysis begins with obtaining a plurality of measured waveforms, for example from two or more receivers of an acoustic logging tool placed in a borehole. The measured waveforms are divided into common gathers, and waveforms of each common gather are enhanced. The enhancement begins by calculating a travel time curve for a selected target mode of the common gather waveforms. Using the travel time curve, waveforms of the selected target mode are aligned to have zero apparent slowness. The aligned waveforms are filtered to suppress non-target mode waves. The aligned waveforms are then enhanced, and used to generate an enhanced dispersion curve of the selected target mode.

A technique includes receiving data acquired by an acoustic measurement tool in a well, where the data represents multiple acoustic modes, including a first order formation flexural acoustic mode and a higher order formation flexural acoustic mode. The technique includes processing the data to identify the higher order formation flexural acoustic mode; and determining a shear slowness based at least in part on slowness values that are associated with the identified higher order formation flexural acoustic mode.

Seismic acquisition having high geophone densities is compressed based on Functional Quantization (FQ) for an infinite dimensional space. Using FQ, the entire sample path of the seismic waveform in a target function space is quantized. An efficient solution for the construction of a functional quantizer is given. It is based on Monte-Carlo simulation to circumvent the limitations of high dimensionality and avoids explicit construction of Voronoi regions to tessellate the function space of interest. The FQ architecture is then augmented with three different Vector Quantization (VQ) techniques which yield hybridized FQ strategies of 1) FQ-Classified VQ, 2) FQ-Residual/Multistage VQ and 3) FQ-Recursive VQ. Joint quantizers are obtained by replacing regular VQ codebooks in these hybrid quantizers by their FQ equivalents. Simulation results show that the FQ combined with any one of the different VQ techniques yields improved rate-distortion compared to either FQ or VQ techniques alone.