System and method for shooting plural seismic sources Si in a marine acquisition system with a deblending-designed dithering sequence DS.sub.new. The method includes generating the deblending-designed dithering sequence DS.sub.new to include random dithering times D.sub.i, a range of the dithering times D.sub.i being larger than a preset, non-zero, minimum value pmv, selecting a shooting sequence SS for the plural seismic sources Si; and shooting the plural seismic sources Si with the deblending-designed dithering sequence DS.sub.new, based on the shooting sequence SS. All odd or all even members of the shooting sequence SS are shot with zero dithering times.

Techniques are disclosed relating to deblending of sources in multi-source geophysical survey data, including marine or land-based data. Recorded data may be aligned to a primary source. A deblending procedure may be iteratively applied to produce a residual term and deblended estimates for the primary source and one or more secondary sources. Following an iteration of the deblending procedure, the resultant data may be sorted according to a domain that renders the one or more secondary sources incoherent with respect to the primary source. The domain used for sorting may be different from a domain used to sort during an immediately prior iteration. In embodiments, the deblending procedure may use coherency filtering, and the coherency filtering may be weighted according to a signal-to-noise metric generated from the data being deblended.

A system for constraining a dither time can comprise a source and a controller coupled to the source. The controller can be configured to actuate the source in sequence, while the source is moving through a fluid volume at a bottom speed, with an actuation time interval between each actuation comprising a sum of a nominal time and a dither time for each actuation and constrain the dither time for each actuation such that a reduction of the actuation time interval relative to a directly precedent actuation time interval is at most a threshold dither time difference, wherein the threshold dither time difference corresponds to a maximum bottom speed.

Acquiring seismic data using time-distributed sources and converting the acquired data into impulsive data using a multiple-frequency approach. The methods are performed in frequency-source location domain, frequency-wavenumber domain, or frequency-slowness domain. The methods are applicable to single source acquisition or simultaneous source acquisition.

Deblending and deghosting seismic data may include processing blended seismic data acquired after actuation of a first seismic source located at a first depth and a second seismic source located at a second depth. The processing may comprise deblending and deghosting the blended seismic data based on a difference in ghost responses of the first seismic source and the second seismic source.

A seismic data acquisition system includes a streamer spread including plural streamers that extend along an inline direction X; a set of front sources that are positioned ahead of the streamer spread along the inline direction X; and a set of top sources that are positioned on top of the streamer spread, along a horizontal direction that is perpendicular to the inline direction X. A characteristic of the set of front sources is different from a characteristic of the set of top sources, and bins corresponding to collected seismic data from each source set are interleaved.

Methods and systems for seismic data acquisition in a survey area use compressed sensing and take into consideration operational limitations. The operational limitations may be related to the equipment used for the survey, the topography of the surveyed area or limitations that otherwise optimize the survey path.

Enclosed herein are a method and system for reduction of a tool wave excited by a transmitter of the well logging tool. In one embodiment, a method comprises transmitting, by a primary transmitter, a primary acoustic wave into a geologic formation which excites a tool wave and a formation wave in the geologic formation, wherein the logging tool comprises a tool wave propagating factor which is different from a formation wave propagating factor; receiving, by one or more receivers, the formation wave and the tool wave; propagating waveform data associated with the received tool wave and formation wave based on a distance between the auxiliary receiver and a primary receiver; and reducing the tool wave in waveform data associated with the formation wave and the tool wave received by a primary receiver of the one or more receivers based on the propagated waveform data.

A method includes acquiring blended seismic data representing a subsurface volume of interest from a plurality of seismic sources, estimating a signal mode using one or more first priors by applying sparse inversion to the blended seismic data, predicting multi-source interference in the blended seismic data based at least in part on the estimated signal mode, removing the estimated signal mode and the predicted multi-source interference from the blended seismic data, such that a residual signal is left, and estimating a coherent signal from the residual signal by solving a sparse inversion.

Techniques are disclosed relating to acquisition and imaging for marine surveys. In some embodiments, a transition survey that uses both one or more sources of a first type (e.g., impulsive sources) and one or more sources of a second type (e.g., vibratory sources) may facilitate calibration of prior surveys that use the first type of sources with subsequent surveys that use the second type of source. In some embodiments, the different types of sources may be operated simultaneously at approximately the same location. In some embodiments, signals generated by the sources are separated, e.g., using deconvolution. The signals may then be compared to generate difference information, which in turn may be used to adjust sensor measurements from a previous or subsequent survey. In various embodiments, the disclosed techniques may improve accuracy in images of geological formations and may facilitate transitions to new types of seismic sources while maintaining continuity in 4D surveys.