Processes and systems for deblending blended seismic data with attenuated source signatures and free-surface effects are described. The blended seismic data may have been recorded in a marine survey in which multiple sources are activated in the body of water above a subterranean formation. Receivers record overlapping pressure and vertical velocity wavefield responses from the subterranean formation as corresponding blended pressure wavefield and blended vertical velocity wavefield. Processes and systems compute an upgoing pressure wavefield and a downgoing vertical velocity wavefield based on the blended pressure wavefield and blended vertical velocity wavefield. Deblended primary pressure wavefields are computed based on the upgoing pressure and downgoing vertical velocity. The deblended primary pressure wavefields may be used to generate images of the subterranean formation that are substantially free of source signatures and free-surface effects.

A sensor system includes a triplet element including a first hydrophone, a second hydrophone, and a third hydrophone configured to receive an incoming signal at a first phase, a second phase, and a third phase, respectively, the first to third hydrophones extending along a first direction, and a processor configured to determine an incidence direction of the incoming signal, and to dynamically generate a cardioid null in the incidence direction to reject the incoming signal based on the incoming signal at the first to third phases.

Seismic data are obtained by recording simultaneously in seismic streamer, acquired by activating approximately simultaneously two or more seismic sources towed at two positions in the vicinity of seismic streamers. A residual is updated iteratively for an inversion solution for the activations of the two or more seismic sources. The iterative updating of the residuals utilizes a sequence of overlapping temporal windows containing reflection events and utilizes normal moveout corrections based on largest reflection events in each temporal window. A final updated residual is added to a final updated model result.

A method includes receiving seismic data of a seismic survey; defining a two-dimensional domain in dimensions x and y; identifying a target trace (S, R) of the seismic survey where S represents a source at (x.sub.s, y.sub.s) and where R represents a receiver at (X.sub.R, y.sub.R); defining with respect to the two-dimensional domain, a source trace (S, X.sub.1) as a primary trace, a receiver trace (R, X.sub.2) as a primary trace, and a generator trace (X.sub.1, X.sub.2) as associated with an interbed multiple generator; convolving the primary traces and crosscorrelating with the generator trace for a plurality of different (X.sub.1, X.sub.2) pairs where each of the plurality of (X.sub.1, X.sub.2) pairs defines a line segment where the line segments are substantially parallel to one another; and, based at least in part on the convolving the primary traces and crosscorrelating with the generator trace, generating seismic data with attenuated multiple energy.

A method is described for removing the surface ghost from and/or separating wave field data and/or for estimating redatuming operators of the wave field data by effective use of a transform that that relies on the non-uniform distribution of distances with respect to a reference surface or of tuned-source radiation directions of sources and or the non-uniform distribution of receivers with respect to a reference surface to partition or map the wave field from at least two different cones in the transformed domain and using the contribution of sources and or receivers inside at least one of the at least two different cones to estimate a first wave field of interest, a second separated or ghost wave field and/or redatuming operator.

Marine seismic data can be processed to remove or reduce two or more source side acquisition effects jointly when 1) the effects are placed in the same data domain as the received data and 2) the effects are described using the same basis functions which may signify representing the received data and the effects in the same chosen transform domain. The data effects may include source signature removal, source radiation pattern removal, residual shot noise suppression and data regularization, multi-channel reconstruction or regularization, prediction of sea surface multiples, separation of simultaneous sources etc. The joint processing can use iterative or non-iterative inversion technique, where the iterative inversion technique may be a matching pursuit technique.

An apparatus includes a seismic sensor to detect seismic waves having at least a subset of seismic multiples and a machine-readable medium having program code executable by a processor to cause the apparatus to determine seismic measurements of the seismic waves, generate a fitted reflectivity model based on a set of reflectivity models using a nonlinear scheme, and identify a subset of the seismic measurements corresponding to the subset of seismic multiples. The apparatus also includes program code to cause the apparatus to generate a set of reduced-noise seismic measurements based on the subset of the seismic measurements.

Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for generating receiver deghosted output according to a receiver deghosting model. In one aspect, a method includes receiving an offshore seismic dataset of a surveyed subsurface that includes a seismic wavefield and is collected by receivers that comprise a streamer that is deployed relative to a water surface; determining an initial plane value for the water surface reflectivity and an initial location value for a position of the streamer; generating a receiver deghosting model by backward and forward propagating the seismic wavefield at the water surface to streamer locations, the receiver deghosting model including tuning parameters; adjusting the tuning parameters according to an adaptive target residue and an inversion target residue; generating receiver deghosted output according to the tuned receiver deghosting model; and determining a productivity of the surveyed subsurface based on the receiver deghosted output.

A method includes receiving, via a processor, input data based upon received seismic data, migrating, via the processor, the input data via a pre-stack depth migration technique to generate migrated input data, encoding, via the processor, the input data via an encoding function as a migration attribute to generate encoded input data having a migration function that is non-monotonic versus an attribute related to the input data, migrating, via the processor, the encoded input data via the pre-stack depth migration technique to generate migrated encoded input data, and generating an estimated common image gather based upon the migrated input data and the migrated encoded input data. The method also includes generating a seismic image utilizing the estimated common image gather, wherein the seismic image represents hydrocarbons in a subsurface region of the Earth or subsurface drilling hazards.

Seismic data are obtained by recording simultaneously in seismic streamer, acquired by activating approximately simultaneously two or more seismic sources towed at two positions in the vicinity of seismic streamers. A residual is updated iteratively for an inversion solution for the activations of the two or more seismic sources. The iterative updating of the residuals utilizes a sequence of overlapping temporal windows containing reflection events and utilizes normal moveout corrections based on largest reflection events in each temporal window. A final updated residual is added to a final updated model result.