Abstract: Fast anisotropy axis values are determined for each bin in seismic data binned by azimuth. A fast azimuth gather is determined within each bin in the seismic data from the fast anisotropy axis values. The earth's subsurface is imaged, using the fast azimuth gathers.

Abstract: Methods and apparatus for noise removal from seismic data. In one embodiment, a seismic data set comprising a plurality of traces is received, and noise metrics for the seismic data set are computed using a set of time and depth windows. The seismic data set is scanned to determine a first set of groups. Each group in the first set comprises at least a first minimum number of neighboring traces for which at least one of the noise metrics is outside a predefined specification. Noise attenuation is applied to the traces in the first set of groups. Other embodiments, aspects, and features are also disclosed.

Abstract: Disclosed are methods and apparatus for noise removal from seismic data. In one embodiment, a seismic data set comprising a plurality of traces is received, and noise metrics for the seismic data set are computed using a set of time and depth windows. The seismic data set is scanned to determine a first set of groups. Each group in the first set comprises at least a first minimum number of neighboring traces for which at least one of the noise metrics is outside a predefined specification. Noise attenuation is applied to the traces in the first set of groups. Other embodiments, aspects, and features are also disclosed.

Abstract: Fast anisotropy axis values are determined for each bin in seismic data binned by azimuth. A fast azimuth gather is determined within each bin in the seismic data from the fast anisotropy axis values. The earth's subsurface is imaged, using the fast azimuth gathers.

Abstract: Marine seismic data are acquired, using a seismic vessel. The acquired marine seismic data are transferred in near-real time to a programmable computer. The programmable computer is used to perform the following. An acoustic 3-D full-waveform inversion is applied to the transferred marine seismic data, generating a high-resolution 3-D velocity field in near-real time. The velocity field is used to apply migration to the transferred marine seismic data, generating an image of the earth's subsurface in near-real time.

Abstract: A super-gather is constructed by interleaving traces from a hydrophone gather and a geophone gather in seismic data such that traces pertaining to co-located hydrophones and geophones are adjacent to each other. A noise-attenuated super-gather, generated by applying an f-x domain noise identifying and attenuation process to the super-gather, is subtracted from the super-gather to generate a super-gather noise model. A hydrophone gather noise model, generated by removing non-noisy geophone gather traces from the super-gather noise model, is subtracted from the hydrophone gather to generate seismic data with interference noise attenuated.

Abstract: A method is disclosed for processing seismic data from concurrently recorded co-located pressure sensors and geophones. The seismic data are processed by first determining an upgoing wavefield and a downgoing wavefield in the seismic data. Adaptive subtraction is then applied to at least one of the upgoing wavefield and the downgoing wavefield to remove the noise from the signal. In alternative embodiments, the upgoing wavefield can be used as a noise model for the downgoing wavefield or the downgoing wavefield can be used as a noise model for the upgoing wavefield.

Abstract: A method is disclosed for separating energy resulting from actuating at least two different seismic energy sources from seismic signals. The sources are actuated to provide a variable time delay between successive actuations of a first one and a second one of the sources. The method includes sorting the seismic signals such that events therein resulting from actuations of the first source are substantially coherent in all spatial directions, coherency filtering the first source coherency sorted signals, sorting the seismic signals such that events therein resulting from actuations of the second source are substantially coherent in all spatial directions, and coherency filtering the second source coherency sorted signals.

Abstract: A method is disclosed for separating energy resulting from actuating at least two different seismic energy sources from seismic signals. The sources are actuated to provide a variable time delay between successive actuations of a first one and a second one of the sources. The method includes sorting the seismic signals such that events therein resulting from actuations of the first source are substantially coherent in all spatial directions, coherency filtering the first source coherency sorted signals, sorting the seismic signals such that events therein resulting from actuations of the second source are substantially coherent in all spatial directions, and coherency filtering the second source coherency sorted signals.

Abstract: A method is disclosed for processing seismic data from concurrently recorded co-located pressure sensors and geophones. The seismic data are processed by first determining an upgoing wavefield and a downgoing wavefield in the seismic data. Adaptive subtraction is then applied to at least one of the upgoing wavefield and the downgoing wavefield to remove the noise from the signal. In alternative embodiments, the upgoing wavefield can be used as a noise model for the downgoing wavefield or the downgoing wavefield can be used as a noise model for the upgoing wavefield.

Abstract: A method is disclosed for attenuating noise from marine seismic signals caused by a noise in the water. The method includes determining an arrival time of a noise event at each of a plurality of seismic sensors, estimating a position of the noise source from the arrival times, and attenuating the noise event from the signals detected by the seismic sensors.

Abstract: A method is disclosed for attenuating noise from marine seismic signals caused by a noise source in the water. The method includes determining an arrival time of a noise event at each of a plurality of seismic sensors, estimating a position of the noise source from the arrival times, and attenuating the noise event from the signals detected by the seismic sensors.