Seismic Image Filtering Machine to Generate a Filtered Seismic Image, Program Products, and Related Methods

A seismic image filtering machine to create a filtered seismic image on a display responsive to filtered seismic image data generated by attenuating coherent seismic noise from surface waves of an unfiltered wavefield constructed from unfiltered seismic image data through a single downward extrapolation of the unfiltered wavefield using a plurality of nonstationary convolution operators to perform localized filtering at each of a plurality of spatial locations of an unfiltered wavefield, the seismic image filtering machine comprising:

• a first database storing unfiltered, unsorted seismic image data derived from a plurality of seismic energy signals received from a seismic energy receiver at a recording surface after propagating throughout a surface wave propagation zone;
• a computer adapted to be in communication with the first database and having at least a processor, memory, and a display;
• an unfiltered wavefield constructor computer readable program product stored in a tangible computer readable storage medium and including instructions that, when executed by the computer, cause the computer to perform the operation of constructing an unfiltered wavefield delineated by a plurality of spatial locations from the unfiltered, unsorted seismic image data stored in the first database;
• a nonstationary convolution operator builder computer readable program product stored in a tangible computer readable storage medium and including instructions that, when executed by the computer, cause the computer to perform the operation of building, responsive to the unfiltered wavefield constructer computer readable program product, a plurality of nonstationary convolution operators, one for each of the plurality of spatial locations of the unfiltered wavefield, each of the nonstationary convolution operators being based on a coordinate location of each of the plurality of spatial locations of the unfiltered wavefield and the space-variant velocity, temporal frequency, transverse wavenumber, and wavelength of the unfiltered wavefield at each spatial location;
• a localized filter computer readable program product stored in a tangible computer readable storage medium and including instructions that, when executed by the computer, cause the computer to perform the operation of locally filtering each of the plurality of spatial locations of the unfiltered wavefield using, at each spatial locations, at least one of the plurality of nonstationary convolutions operators associated with that one of the plurality of spatial locations to thereby effectuate a single downward extrapolation of the unfiltered wavefield;
• and
• a filtered seismic image creator computer readable program product stored in a tangible computer readable storage medium and including instructions that, when executed by the computer, cause the computer to perform the operation of creating, on the display, a filtered seismic image responsive to converting filtered seismic image data into a graphic image form capable of being displayed on the display, the filtered seismic image data being generated responsive to filtering in the localized filter computer readable program product the unfiltered wavefield at each of the plurality of spatial locations of the unfiltered wavefield.

A computer readable program product stored in a tangible computer readable storage medium and including instructions that when executed by a computer cause the computer to perform the operations of:

• constructing an unfiltered wavefield delineated by a plurality of spatial locations from unfiltered, unsorted seismic image data generated responsive to a plurality of seismic energy signals propagated through a surface wave propagation zone and received from a seismic image receiver;
• building, for each of the plurality of spatial locations of the unfiltered wavefield, a plurality of nonstationary convolution operators, one for each of the plurality of spatial locations of the unfiltered wavefield, each of the nonstationary convolution operators being based on a coordinate location of each of the plurality of spatial locations of the unfiltered wavefield and a space-variant velocity, temporal frequency, transverse wavenumber, and wavelength of the unfiltered wavefield at each of the plurality of spatial locations;
• filtering, in a space-frequency domain, each of the plurality of spatial locations of the unfiltered wavefield using, at each of the plurality of spatial locations, at least one of the plurality of nonstationary convolution operators associated with that one of the plurality of spatial locations;
• and
• generating a filtered seismic image on one or more output devices, each adapted to be in communication with the computer, responsive to each of the plurality of spatial locations of the unfiltered wavefield filtered in the space-frequency domain.