Abstract: A method for identifying clock timing discrepancies in at least one clock of interest that is associated with a marine seismic receiver, comprises collecting from at least one marine receiver other than the receiver of interest a first data set corresponding to a selected time period, said first data set being selected to include ocean wave signals; collecting from the receiver of interest a second data set corresponding to the selected time period, said second data set being selected to include ocean wave signals; applying a mathematical prediction technique to the ocean wave signals in the first data set so as to generate a predicted response for a receiver co-located with the receiver of interest; comparing the predicted response to the second data set so as to generate a correlation data set; and using the correlation data set to determine a corrected parameter for the receiver of interest.

Abstract: A method for identifying clock timing discrepancies in a plurality of clocks that are each associated with a seismic receiver, comprises the steps of collecting from at least a pair of receivers a data set corresponding to a selected time period, cross-correlating the data sets between at least one pair of receivers so as to produce cross-correlated data for positive, zero, and negative time lags, comparing the cross-correlated data for the positive and negative time lags to measure a timing asymmetry about the zero-lag time, and, for a receiver pair for which there is a non-zero timing asymmetry, using the asymmetry to identify a timing discrepancy between the clocks associated with that receiver pair. The each data set can be filtered so as to obtain data in a selected frequency range, which may avoid an active shot frequency. The data may be collected in the absence of active seismic shots.

Abstract: A method for collecting information about a subsurface region, comprises a) providing a set of data comprising a plurality of scattered signals, where each scattered signal is a portion of an acoustic seismic signal that has been scattered by and at least one scatterer and received at a receiver, b) using spatial deconvolution to process the scattered signals so as generate a coherent arrival, and c) using the coherent arrival to output human readable information about the subsurface region. The receiver may be a geophone or a fiber optic distributed acoustic sensor and may be in a borehole or at the surface. The acoustic seismic signal may originate at the surface or below the surface and may be an active or passive source.

Abstract: A method of evaluating a formation of interest, comprises collecting a data set comprising signals received at a plurality of receivers signals from a source on a bottom-hole assembly at a position in a borehole, processing the data set so as to create a virtual trace received at a virtual receiver located at the source position, and using the virtual trace to generate an image or measurement containing information about the formation of interest. The source may or may not be a drill bit and the data can be collected at several different source positions.

Abstract: A method for identifying clock timing discrepancies in at least one clock of interest that is associated with a marine seismic receiver, comprises collecting from at least one marine receiver other than the receiver of interest a first data set corresponding to a selected time period, said first data set being selected to include ocean wave signals; collecting from the receiver of interest a second data set corresponding to the selected time period, said second data set being selected to include ocean wave signals; applying a mathematical prediction technique to the ocean wave signals in the first data set so as to generate a predicted response for a receiver co-located with the receiver of interest; comparing the predicted response to the second data set so as to generate a correlation data set; and using the correlation data set to determine a corrected parameter for the receiver of interest.

Abstract: A method for identifying clock timing discrepancies in a plurality of clocks that are each associated with a seismic receiver, comprises the steps of collecting from at least a pair of receivers a data set corresponding to a selected time period, cross-correlating the data sets between at least one pair of receivers so as to produce cross-correlated data for positive, zero, and negative time lags, comparing the cross-correlated data for the positive and negative time lags to measure a timing asymmetry about the zero-lag time, and, for a receiver pair for which there is a non-zero timing asymmetry, using the asymmetry to identify a timing discrepancy between the clocks associated with that receiver pair. The each data set can be filtered so as to obtain data in a selected frequency range, which may avoid an active shot frequency. The data may be collected in the absence of active seismic shots.

Abstract: Method of imaging seismic data recorded using a set of seismic receivers positioned to receive seismic responses from a subsurface formation upon activating a seismic source. The seismic responses are direction-sensitive responses. A virtual signal received by receiver k from the virtual source at the position of receiver m is determined by processing involving cross correlating at least part of the responses of a receiver m with at least part of the responses of a seismic receiver k. Part of direction-sensitive responses or part of the virtual signal that contains a component of the wave field at receiver m traveling in a first direction and part of the direction-sensitive responses or part of the virtual signal that contains a component of the wave field at the receiver k traveling in a second direction may be removed.

Abstract: Method of imaging seismic data recorded using a set of seismic receivers positioned to receive seismic responses from a subsurface formation upon activating a seismic source. The seismic responses are direction-sensitive responses. A virtual signal received by receiver k from the virtual source at the position of receiver m is determined by processing involving cross correlating at least part of the responses of a receiver m with at least part of the responses of a seismic receiver k. Part of direction-sensitive responses or part of the virtual signal that contains a component of the wave field at receiver m traveling in a first direction and part of the direction-sensitive responses or part of the virtual signal that contains a component of the wave field at the receiver k traveling in a second direction may be removed.