Abstract: Estimation of velocity models inclusive of receiving seismic data inclusive of data that corresponds to a seismic image, adding a velocity perturbation to a current velocity model that represents a portion of the subsurface responsible for a distortion in the seismic image to generate a perturbed velocity model, generating an image via seismic migration of the seismic data and the perturbed velocity model, generating and assigning a measure of quality to the image, determining whether the measure of quality assigned to the image is an optimal measure of quality at a particular location of the current velocity model, and updating the current velocity model to generate a revised velocity model utilizing the measure of quality assigned to the image when the measure of quality assigned to the image is determined to be the optimal measure of quality at the particular location of the current velocity model.

Abstract: Techniques to avoid a cycle skip in conjunction with a full waveform inversion are disclosed herein. A method includes selecting a first objective function of a full waveform inversion (FWI) from a set of objective functions, selecting a second objective function of the FWI from the set of objective functions, calculating a first misfit based upon the first objective function using modeled data with respect to observed data, calculating a first search direction based upon the first misfit between the modeled data and the observed data, calculating a second misfit based upon the second objective function using the modeled data with respect to the observed data, calculating a second search direction based upon the second misfit between the modeled data and the observed data, combining the first search direction with the second direction and computing an update to the modeled data based upon the first search direction and the second search direction combination.

Abstract: Techniques, systems and devices to generate a seismic wavefield solution. This includes receiving a velocity model corresponding to at least one attribute of seismic data, receiving source wavelet data corresponding to the seismic data, generating a guide image based upon at least one attribute of the velocity model, transmitting the velocity model, the source wavelet data, and the guide image to a machine learning system, and training the machine learning system into a trained machine learning system using the velocity model, the source wavelet data, and the guide image.

Abstract: Estimation of velocity models inclusive of receiving seismic data inclusive of data that corresponds to a seismic image, adding a velocity perturbation to a current velocity model that represents a portion of the subsurface responsible for a distortion in the seismic image to generate a perturbed velocity model, generating an image via seismic migration of the seismic data and the perturbed velocity model, generating and assigning a measure of quality to the image, determining whether the measure of quality assigned to the image is an optimal measure of quality at a particular location of the current velocity model, and updating the current velocity model to generate a revised velocity model utilizing the measure of quality assigned to the image when the measure of quality assigned to the image is determined to be the optimal measure of quality at the particular location of the current velocity model.

Abstract: According to one embodiment, there is provided a method of correcting recorded seismic data where each receiver clock is potentially inaccurate. Since the seismic wave field is not random, and contains coherent events that are recorded by all receivers in a local area, it is possible to estimate the differences in the time reference by comparing the recordings of different receivers in a local area. With no external time reference, time signal, or pilot trace, an entire seismic data itself can be used to determine how each receiver's clock is drifting from true time.

Abstract: According to one embodiment, there is provided a method of correcting recorded seismic data where each receiver clock is potentially inaccurate. Since the seismic wave field is not random, and contains coherent events that are recorded by all receivers in a local area, it is possible to estimate the differences in the time reference by comparing the recordings of different receivers in a local area. With no external time reference, time signal, or pilot trace, an entire seismic data itself can be used to determine how each receiver's clock is drifting from true time.

Abstract: A method for use in seismic exploration comprises: accessing a set of seismic data representative of a subterranean geological formation and a subsurface attribute model of the subterranean geological formation; performing a wavefield extrapolation on the seismic data in the subsurface attribute model; applying the time-shift extended imaging condition to the extrapolated wavefields; forming shot-indexed, time shift gathers for each image pixel of the subsurface attribute model from the conditioned extrapolated wavefields; adaptively focusing the gathers; and stacking the adaptively focused gathers; and imaging the subterranean geological formation from the stacked, adaptively focused gathers. The method may, in some aspects, be realized by a computing apparatus programmed to perform the method or as a set of instructions encoded on a non-transitory program storage medium that, when executed by a computing apparatus, perform the method.

Abstract: A technique for use in geophysical surveying acquires seismic data at low seismic frequencies to generate better starting models for subsurface attributes rather than enhancing the bandwidth of airguns for broadband imaging as in conventional practice.

Abstract: The instant invention is designed to provide an adaptive approach to removing short-period time/phase distortions within a downward-continuation process that is a key component of seismic migration algorithms. Using techniques analogous to residual statics corrections that are used in standard seismic processing, one inventive approach estimates and removes the effects of short wavelength velocity disruptions, thereby creating clearer seismic images of the subsurface of the earth. Additionally, the instant method will provide an updated velocity model that can be used to obtain further image improvement.

Abstract: The instant invention is designed to provide an adaptive approach to removing short-period time/phase distortions within a downward-continuation process that is a key component of seismic migration algorithms Using techniques analogous to residual statics corrections that are used in standard seismic processing, one inventive approach estimates and removes the effects of short wavelength velocity disruptions, thereby creating clearer seismic images of the subsurface of the earth. Additionally, the instant method will provide an updated velocity model that can be used to obtain further image improvement.

Abstract: A technique for use in geophysical surveying acquires seismic data at low seismic frequencies to generate better starting models for subsurface attributes rather than enhancing the bandwidth of airguns for broadband imaging as in conventional practice.

Abstract: A method for use in seismic exploration comprises: accessing a set of seismic data representative of a subterranean geological formation and a subsurface attribute model of the subterranean geological formation; performing a wavefield extrapolation on the seismic data in the subsurface attribute model; applying the time-shift extended imaging condition to the extrapolated wavefields; forming shot-indexed, time shift gathers for each image pixel of the subsurface attribute model from the conditioned extrapolated wavefields; adaptively focusing the gathers; and stacking the adaptively focused gathers; and imaging the subterranean geological formation from the stacked, adaptively focused gathers. The method may, in some aspects, be realized by a computing apparatus programmed to perform the method or as a set of instructions encoded on a non-transitory program storage medium that, when executed by a computing apparatus, perform the method.