A method of seismic exploration above a region of the subsurface containing structural or stratigraphic features conducive to the presence, migration, or accumulation of hydrocarbons comprises accessing at least a portion of a blended seismic source survey, separating the at least two interfering seismic source excitations using inversion separation, producing one or more source gathers based on the separating, and using the one or more source gathers to explore for hydrocarbons within said region of the subsurface. The blended source seismic survey contains at least two interfering seismic source excitations therein, and the seismic source excitations can be produced by seismic source types having different signatures or frequency characteristics.

A method is described for seismic inversion including receiving a processed seismic image and an enhanced seismic image representative of a subsurface volume of interest; forward modeling the processed seismic image and the enhanced seismic image to generate a first modeled dataset and a second modeled dataset; differencing the first modeled dataset and the second modeled dataset to create a residual dataset; filtering the first modeled dataset to generate an approximation of illumination; preconditioning the residual dataset with the approximation of illumination to generate an adjoint source; back projecting the adjoint source to determine a model update; and applying the model update to an earth model of the subsurface volume of interest. The method may be executed by a computer system.

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.

Systems and methods of performing a seismic survey are described. The system can receive seismic data in a first domain, and transform the seismic data into a tau-p domain. The system can identify a value on an envelope in the tau-p domain, select several values on the tau-p envelope using a threshold, and then generate a masking function. The system can combine the masking function with the tau-p transformed seismic data, and then perform an inverse tau-p transform on the combined seismic data. The system can adjust amplitudes in the inverse tau-p transformed combined seismic data, and identify one or more coherent events corresponding to subsea lithologic formations or hydrocarbon deposits.

Inversion for marine seismic imaging of a full reflected wavefield can include generating an image of a subsurface formation by full wavefield migrating a recorded seismic wavefield and generating numerically modeled data using the image. A mismatch between the numerically modeled data and the seismic wavefield can be determined. Responsive to determining that the mismatch exceeds an inversion match threshold, the image can be updated using the mismatch between the numerically modeled data and the seismic wavefield.

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.

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.

Method for acquiring seismic data is described. The method includes determining a non-uniform optimal sampling design that includes a compressive sensing sampling grid. Placing a plurality of source lines or receiver lines at a non-uniform optimal line interval. Placing a plurality of receivers or nodes at a non-uniform optimal receiver interval. Towing a plurality of streamers attached to a vessel, wherein the plurality of streamers is spaced apart at non-uniform optimal intervals based on the compressive sensing sampling grid. Firing a plurality of shots from one or more seismic sources at non-uniform optimal shot intervals. Acquiring seismic data via the plurality of receivers or nodes.

A method for applying separated wave-field imaging onshore (1) by artificially creating up-going and down-going fields and (2) by using these fields in a migration algorithm. If there are any surface multiples in the data, the resulting image created using the migration algorithm will be distorted by the unknown free-surface reflection coefficient. In fact, the surface multiples may be generated with a complex series of reflection coefficients. The distortions found in the resulting image created using the migration algorithm are then removed.

Methods and apparatuses for processing seismic data acquired with multicomponent sensors build an accurate S-wave velocity model of a surveyed underground formation using a full waveform inversion (FWI) approach. PS synthetic data is generated using approximative acoustic equations in anisotropic media with a P-wave model, a current S-wave velocity model and a reflectivity model as inputs. The current S-wave velocity model is updated using FWI to minimize an amplitude-discrepancy-mitigating cost function that alleviates the amplitude mismatch between the PS observed data and the PS synthetic data due to the use of the approximative acoustic equations.