The invention relates to continuously or near continuously acquiring seismic data where at least one pulse-type source is fired in a distinctive sequence to create a series of pulses and to create a continuous or near continuous rumble. In a preferred embodiment, a number of pulse-type seismic sources are arranged in an array and are fired in a distinctive loop of composite pulses where the returning wavefield is source separable based on the distinctive composite pulses. Firing the pulse-type sources creates an identifiable loop of identifiable composite pulses so that two or more marine seismic acquisition systems with pulse-type seismic sources can acquire seismic data concurrently, continuously or near continuously and the peak energy delivered into the water will be less, which will reduce the irritation of seismic data acquisition to marine life.

A method for configuring a multi-source and a hexa-source for acquiring first and second seismic datasets of a subsurface. The method includes selecting a number n of source arrays to create the multi-source; selecting a number m of sub-arrays for each source array, each sub-array having a plurality of source elements; imposing a distance D between any two adjacent source arrays of the multi-source; calculating a distance d between any two adjacent sub-arrays of a same source array so that bins associated with the first and second seismic datasets are interleaved; selecting source elements from at least six different sub-arrays of the n source arrays to create the hexa-source; and firing the multi-source to acquire the first dataset, and firing the hexa-source to acquire the second dataset.

Systems and methods for deployment and retrieval of ocean bottom seismic receivers. In some embodiments, the system includes a carrier containing receivers. The carrier can include a frame having a mounted structure (e.g., a movable carousel, movable conveyor, fixed parallel rails, or a barrel) for seating and releasing the receivers (e.g., axially stacked). The structure can facilitate delivering receivers to a discharge port on the frame. The system can include a discharge mechanism for removing receivers from the carrier. In some embodiments, the method includes loading a carrier with receivers, transporting the carrier from a surface vessel to a position adjacent the seabed, and using an ROV to remove receivers from the carrier and place the receivers on the seabed. In some embodiments, an ROV adjacent the seabed engages a deployment line that guides receivers from the vessel down to the ROV for on-time delivery and placement on the seabed.

Systems and methods for deployment and retrieval of ocean bottom seismic receivers. In some embodiments, the system includes a carrier containing receivers. The carrier can include a frame having a mounted structure (e.g., a movable carousel, movable conveyor, fixed parallel rails, or a barrel) for seating and releasing the receivers (e.g., axially stacked). The structure can facilitate delivering receivers to a discharge port on the frame. The system can include a discharge mechanism for removing receivers from the carrier. In some embodiments, the method includes loading a carrier with receivers, transporting the carrier from a surface vessel to a position adjacent the seabed, and using an ROV to remove receivers from the carrier and place the receivers on the seabed. In some embodiments, an ROV adjacent the seabed engages a deployment line that guides receivers from the vessel down to the ROV for on-time delivery and placement on the seabed.

Source element of a source subarray can be individually actuated according to an actuation sequence. The actuation sequence can be at least partially based on a relative position of each of the source elements within a particular geometry of the source subarray with respect to a previously actuated source element and a towing velocity of the source subarray.

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.

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.

A system can include a source and a front float coupled to the source. The front float can include a winch configured to adjust a position of the source. The front float can include a control unit configured to control functions associated with the front float. Lead-ins can be coupled to the front float and the source and configured to accommodate transfer of electrical energy between the front float and the 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.