Computing device, computer instructions and method for processing input seismic data d associated with a surveyed subsurface. The method includes: receiving the input seismic data d recorded in a first domain by seismic receivers that travel in water, the input seismic data d including pressure data and particle motion data; generating a model p in a second domain, which is different from the first domain, to describe the input seismic data d; processing the model p to generate an output seismic dataset with attenuated noise; and generating an image of the surveyed subsurface based on the output seismic dataset.

A method for removing multiples m from seismic data d associated with a subsurface, the method including receiving the seismic data d associated with the subsurface, forward propagating the seismic data d into the subsurface to form forward propagated data d.sub.?; receiving angular dependent reflectivities r.sub.?, associated with an angular range ??, in the subsurface, for a given point; generating an angle dependent reflecting wavefield D.sub.??r.sub.? based on the forward propagated data d.sub.? and the angular dependent reflectivities r.sub.?; calculating a multiple model ?D.sub.??r.sub.? by forward propagating the angle dependent reflecting wavefield D.sub.??r.sub.? to the receiver; attenuating multiplies m associated with the multiple model, from the seismic data d, by subtraction of the multiple model to calculate demultiple data dd; and generating an image of the subsurface.

A method for internal multiple attenuation of seismic data associated with a subsurface. The method includes receiving seismic data d associated with the subsurface, wherein the seismic data d includes primaries and internal multiples, receiving a first reflectivity r.sub.1 associated with a first formation in the subsurface, calculating a second reflectivity r.sub.2 associated with a second formation in the subsurface, based on wavefield extrapolation of the seismic data d and a reflection in the first reflectivity r.sub.1, wherein the second formation is different from the first formation, calculating the internal multiples using (1) wavefield extrapolation of the seismic data d, (2) the reflection in the first reflectivity r.sub.1, and (3) a reflection in the second reflectivity r.sub.2, attenuating the internal multiplies from the seismic data d by subtraction, and generating an image of the subsurface indicative of geophysical features associated with oil or gas resources.

In order to use near-field measurements to obtain signature of a signal penetrating seafloor in a shallow water surveyed area, the water-bottom reflections' effect is removed. The removal is performed by obtaining first a far-field initial estimate from stacked primary pulses in the near-field measurements, and then estimating water-bottom reflection portions for different depths using differences between the near-field measurements and the far-field initial estimate. The signature of the air-gun for each shot is then deblended from the near-field measurement for the shot using the one of the water-bottom reflection portions according to a water-bottom depth associated with the shot location.

A method can include selecting a location associated with a seismic survey geometry; selecting a trace for the location where the trace is selected from one of a plurality of different types of traces that include real data traces, interpolated data traces and model data traces; generating a multiple model based at least in part on the selected trace; and adjusting seismic data based at least in part on the multiple model.

A method for determining seismic sensor depths in a body of water includes accepting as input to a computer measurements of seismic signals made by a plurality of seismic sensors disposed in a body of water. A depth increment and a range of sensor depths for correlation of signals from each of the plurality of seismic sensors is defined. In the computer, the input seismic measurements are extrapolated to each depth increment in the range. A depth of each seismic sensor is determined by correlating the seismic signal measurements with depth-extrapolated measurements of the seismic signal measurements.

A system and method for acquiring seismic streamer data is provided. Embodiments may include performing a marine seismic survey using an unmanned marine vessel having a power source configured to drive and provide propulsion to the unmanned marine vessel. Embodiments may further include acquiring one or more of long and ultra-long seismic survey data using a multi-dimensional seismic sensor array coupled with the unmanned marine vessel and providing the seismic survey data as a reduced data set that includes long and ultra long offsets.

An apparatus for marine seismic surveying includes four seismic sources, each comprising three independent source subarrays, wherein, for each source: each subarray is configured to be towed at a different one of three selected depths, each subarray has a same total volume, and each subarray comprises a same number of source elements; wherein the four sources share the three independent subarrays such that the source array consists of six subarrays. A method for marine seismic surveying includes towing six source subarrays with a survey vessel; and sequentially actuating four sets of three of the six subarrays to generate a source signal with each actuation, wherein, for each of the four sets, the three of the six subarrays: are towed at three different selected depths, have a same total volume, and comprise a same number of source elements.

Marine seismic use of a harmonic distorted signal can include calculating a source wavefield based on nearfield measurements of a direct arrival signal from a marine vibrator source including harmonic distortion, calculating a receiver wavefield based on far-field measurements of a signal from the marine vibrator source after reflection from a subsurface location, and performing a multidimensional deconvolution of a source ghost effect, a source signature effect, and the harmonic distortion from the calculated receiver wavefield to determine a reflectivity of the subsurface location with the harmonic distortion suppressed.

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.