Westerngeco L.l.p.

Cgg Services Sas

Cggveritas Services S.a.

Richard Bale

Yi Wang

Sergio Grion

Stephen Horne

Methods and systems for separating P-S wave field data are described. Slowness values for the PP mode and the PS mode are estimated and are, typically, unequal based on aliased and/or irregularly sampled data. A calculation, in the space-time domain, based on a matrix of equations, generates separated P-wave and S-wave data. The separated P-wave data and S-wave data are output for further imaging.

P-wave and S-wave separation of seismic data in the presence of statics and irregular geometry

Device and method for processing 4-dimensional (4-D) seismic traces. The method includes receiving at least two vintages of seismic traces recorded by seismic receivers for a same subsurface area, wherein said seismic receivers are located at the ocean floor; applying up-down deconvolution to each of said vintages of seismic traces to obtain a representation of a reflectivity of said subsurface area from each vintage of seismic traces; and redatuming the up-down deconvolution result of each vintage from the ocean floor to a desired water depth of the ocean to reduce one or more changes in said seismic traces associated with water layer variations between recordings of said series of seismic traces. The redatumed seismic data is used to generate one or more images representing characteristics of said subsurface area.

Methods and systems to eliminate undesirable variations in time-lapse seismic surveys

A method of processing geophysical data including determining the azimuth of a mirror symmetry plane within the earth from the geophysical data having sets of geophysical data acquired with different source-receiver azimuths. The data are processed to determine attributes of the geophysical data that are azimuth-dependent. One azimuth-dependent attribute of the geophysical data is selected, and a value of the source-receiver azimuth about which the selected attribute exhibits mirror symmetry is determined. This locates a mirror symmetry plane within the earth. The value of the source-receiver azimuth may be determined by generating an objective function indicative of the difference between the actual value of an attribute at one azimuth and the value predicted for that attribute at that azimuth using a trial estimate of the azimuth of a mirror symmetry plane, and finding the azimuth of a mirror symmetry plane that minimizes the objective function.

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Calgary, Canada

Richard Bale