There is a method for correcting seismic wave propagation paths through the earth. The method includes determining a first fixed shooting sequence for a first bandlimited seismic source; determining a second shooting sequence for a second bandlimited seismic source, wherein the second shooting sequence includes second shooting positions that correspond to second energy emissions, and the second energy emissions differ from the first energy emissions in at least one of an emission time, phase and amplitude; receiving raw seismic data recorded with seismic receivers and generated as a result of the first and second energy emissions, wherein the raw seismic data is indicative of seismic wave paths from the first and second bandlimited seismic sources to the seismic receivers; separating the raw seismic data into a first bandlimited set corresponding to the first bandlimited seismic source and a second bandlimited set corresponding to the second bandlimited seismic source; and correcting the seismic wave paths, from the first and second bandlimited seismic sources to the seismic receivers, based on at least one of the first and second bandlimited sets.

A method of seismic acquisition using a dispersed-source array (DSA) comprising two or more sources. The method comprises determining, for each of the two or more sources of the DSA, an individual spectrally-banded waveform. For each of the two or more sources, a primary waveform is formed by repeating the individual spectrally-banded waveform. For each of the two or more sources, a secondary waveform is formed based on the primary waveform. The secondary waveform is spectrally shifted relative to the primary waveform such that secondary waveforms of any two of the two or more sources are spectrally non-overlapping. The blending operator based on the secondary waveform of each of the two or more sources is provided to the DSA. The method also includes performing deblended-data reconstruction of acquired seismic data using one or more properties of the blending operators of the two or more sources.

A method for borehole measurements may comprise receiving one or more signals from a linear receiver array, computing an arctan of a Hilbert Transform, isolating a first arriving energy, selecting a reference instantaneous phase on a reference receiver, finding the reference instantaneous phase for the linear receiver array, computing a relative travel time shift, combining a reference pick time with a relative time, and determining a travel time. A system for borehole measurements comprise a conveyance, a bottom hole assembly attached to the conveyance, a linear receiver array, wherein the linear receiver array is disposed on the bottom hole assembly, and a computer system connected to the linear receiver array.

A method for borehole measurements may comprise receiving one or more signals from a linear receiver array, computing an arctan of a Hilbert Transform, isolating a first arriving energy, selecting a reference instantaneous phase on a reference receiver, finding the reference instantaneous phase for the linear receiver array, computing a relative travel time shift, combining a reference pick time with a relative time, and determining a travel time. A system for borehole measurements comprise a conveyance, a bottom hole assembly attached to the conveyance, a linear receiver array, wherein the linear receiver array is disposed on the bottom hole assembly, and a computer system connected to the linear receiver array.

An initial gather of blended seismic signals induced in a common seismic receiver by a plurality of actual sources grouped in actual source groups is provided. Each actual source group has a linear source geometry that is the same for each actual source group. The plurality of sources in each actual source group is fired according to a pre-selected firing sequence that is the same for each actual source group. Actual shot records are created from the blended signals, and fictive shot records are created of seismic signals for fictive source groups that each have the same source geometry as the actual source groups, by interpolation of the actual shot records. Single source shot records of single source signals are separated by discrete deconvolution of the actual shot records and the fictive shot records. The output includes a seismic gather comprising a plurality of the single source shot records.

Processes and systems described herein are directed to performing marine surveys with marine vibrators that emit orthogonal coded pseudo-random sweeps. In one aspect, coded pseudo-random signals are generated based on coded pseudo-random sequences. The coded pseudo-random sequences are used to activate the marine vibrators in a body of water above a subterranean formation. The activated marine vibrators generate orthogonal coded pseudo-random sweeps. A wavefield emitted from the subterranean formation in response to the orthogonal coded pseudo-random sweeps is detected at receivers located in a body of water. Seismic signals generated by the receivers may be cross-correlated with a signature of one of the orthogonal coded pseudo-random sweeps to obtain seismic data with incoherent residual noise.

A method of seismic acquisition using a dispersed-source array (DSA) comprising two or more sources. The method comprises determining, for each of the two or more sources of the DSA, an individual spectrally-banded waveform. For each of the two or more sources, a primary waveform is formed by repeating the individual spectrally-banded waveform. For each of the two or more sources, a secondary waveform is formed based on the primary waveform. The secondary waveform is spectrally shifted relative to the primary waveform such that secondary waveforms of any two of the two or more sources are spectrally non-overlapping. The blending operator based on the secondary waveform of each of the two or more sources is provided to the DSA. The method also includes performing deblended-data reconstruction of acquired seismic data using one or more properties of the blending operators of the two or more sources.

A survey method includes generating a first amplitude modulation signal by amplitude-modulating a carrier wave repeating the same pattern at a predetermined cycle in each of a plurality of vibrators with a modulation signal whose cycle is 1/m times the predetermined period and is different for each of the vibrators, transmitting the seismic wave based on the first amplitude modulation signal, generating a second amplitude modulation signal in one or more receivers, the second amplitude modulation signal being identical to the first amplitude modulation signal generated by any one of the seismic vibrators, generating a reception signal in each of the one or more receivers by receiving a synthetic seismic wave in which the seismic waves generated by the seismic vibrators are synthesized, calculating a correlation value between the reception signal and the second amplitude modulation signal, and analyzing characteristics of the medium on the basis of the correlation value.

A method for borehole measurements may comprise receiving one or more signals from a linear receiver array, computing an arctan of a Hilbert Transform, isolating a first arriving energy, selecting a reference instantaneous phase on a reference receiver, finding the reference instantaneous phase for the linear receiver array, computing a relative travel time shift, combining a reference pick time with a relative time, and determining a travel time. A system for borehole measurements comprise a conveyance, a bottom hole assembly attached to the conveyance, a linear receiver array, wherein the linear receiver array is disposed on the bottom hole assembly, and a computer system connected to the linear receiver array.

Processes and systems described herein are directed to performing marine surveys with marine vibrators that emit orthogonal coded pseudo-random sweeps. In one aspect, coded pseudo-random signals are generated based on coded pseudo-random sequences. The coded pseudo-random sequences are used to activate the marine vibrators in a body of water above a subterranean formation. The activated marine vibrators generate orthogonal coded pseudo-random sweeps. A wavefield emitted from the subterranean formation in response to the orthogonal coded pseudo-random sweeps is detected at receivers located in a body of water. Seismic signals generated by the receivers may be cross-correlated with a signature of one of the orthogonal coded pseudo-random sweeps to obtain seismic data with incoherent residual noise.