Determining a far field signature of a source array can include receiving data associated with a sea surface state and determining a coherent portion and an incoherent portion of a reflection coefficient of the sea surface based on the received data. A notional source signature of each source of the source array can be determined based on the coherent portion, the incoherent portion, and near field data associated with each of the sources, and the far field signature of the source array can be determined based on the notional source signatures of each of the sources. The notional source signature and the far field signature can be stored. A seismic image of a subsurface location can be generated based on the determined far field signature.

Computing device, computer instructions and method process input seismic data d recorded in a first domain by seismic receivers that travel in water, the input seismic data d including pressure and particle motion measurements, including up-going and down-going wave-fields. A model p is generated in a second domain by solving an inverse problem for the input seismic data d, wherein applying an L transform to the model p describes the input data d. An L transform, which is different from the L transform, is then applied to the model p to obtain an output seismic data in the first domain, the output seismic data having a characteristic imparted by the transform L. The characteristic is related to pressure wave-fields and/or particle motion wave-fields interpolated at positions in-between the input seismic receivers. An image of the surveyed subsurface is generated based on the output seismic dataset.

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.

Prediction and subtraction of multiple diffractions may include transforming previously acquired seismic data from a time-space domain to a transformed domain using a dictionary of compressive basis functions and separating, within the transformed previously acquired seismic data, a first portion and a second portion of the transformed previously acquired seismic data. Prediction and subtraction of multiple diffractions may also include predicting a plurality of multiple diffractions based on the separated first and second portions and adaptively subtracting the predicted multiple diffractions from the previously acquired seismic data. Prediction and subtraction of multiple diffractions may also include inverse transforming a particular seismic data set from the transformed domain to the time-space domain.

Processes and systems described herein are directed to performing marine surveys with a moving vibrational source that emits a continuous source wavefield into a body of water above a subterranean formation. The continuous source wavefield is formed from multiple sweeps in which each sweep is emitted from the moving vibrational source into the body of water with a randomized phase and/or with a randomized sweep duration. Reflections from the subterranean formation are continuously recorded in seismic data as the moving vibrational source travels above the subterranean formation. Processes and systems include iteratively deconvolving the source wavefield from the continuously recorded seismic data to obtain an earth response in the common receiver domain with little to no harmful effects from spatial aliasing and residual crosstalk noise. The earth response may be processed to generate an image of the subterranean formation.

Processes and systems for imaging a subterranean formation using continuously recorded seismic data obtained during a marine seismic geophysical survey of the subterranean formation are described herein. The processes and systems compute upgoing pressure data at stationary-receiver locations. and low-frequency noise attenuation processes and systems are applied to the upgoing pressure wavefield data to obtain low-frequency noise attenuated upgoing pressure wavefield data. An image of the subterranean formation, or data indicative thereof, may be generated using the low-frequency noise attenuated upgoing pressure wavefield data at stationary-receiver locations.

Techniques are disclosed relating to designature of recorded seismic data that includes seismic traces having respective source orientation angles, where the source orientation angles represent deviations in seismic source orientation relative to an inline survey direction. A plurality of designature operators corresponding to respective designature orientation angles within a defined set of designature orientation angles may be generated. For a given member of the defined set of designature orientation angles, a corresponding designature operator may be applied to the recorded seismic data to generate designatured seismic data for the given designature orientation angle. For a given seismic trace having a given source orientation angle, the designatured seismic data may be interpolated to generate a designatured version of the given seismic trace. The results may be stored in a tangible, computer-readable medium.

Embodiments included herein are directed towards a marine seismic streamer. The seismic streamer may include an outer skin formed in a longitudinally extending tubular shape, an inner surface of the outer skin defining an internal volume containing a gel substance. The seismic streamer may also include a plurality of micro-electro-mechanical (MEMS) sensors and a plurality of hydrophones associated with the outer skin, wherein the plurality of MEMS sensors are spaced non-uniformly in the seismic streamer along an axial direction of the streamer, such that not more than 100 MEMS sensors are located in the seismic streamer over a continuous 100 meter axial length of seismic streamer. The seismic streamer may further include an electronics system extending axially through an inside portion of the outer skin and a strength member core extending axially through an inside portion of the outer skin.

Raw 3D seismic streamer wavefield data is received as a receiver-ghosted shot gather. The received receiver-ghosted shot gather shot gather is processed into a normalized form as normalized data. The normalized data is partitioned into a plurality of user-defined sub-gathers and processed to generate a complete receiver-deghosted shot gather. Output of the complete receiver-deghosted shot gather is initiated.

A notional source signature of a bubble may be determined. For example, a method for determining a notional source signature of a bubble can include estimating a position of a bubble created by actuation of an impulsive source. A notional source signature of the bubble can be determined based on the estimate.