Seismology is used for exploration, archaeological studies, and engineering projects that require geological information. Exploration seismology provides data that, when used in conjunction with other available geophysical, borehole, and geological data, can provide information about the structure and distribution of rock types and their contents. Such information greatly aids searches for water, geothermal reservoirs, and mineral deposits such as hydrocarbons and ores. Most oil companies rely on exploration seismology to select sites in which to drill exploratory oil wells.
Seismology employs artificially generated seismic waves to map subsurface structures. The seismic waves propagate from a source down into the earth and reflect from boundaries between subsurface structures. Seismic energy receivers detect and record reflected seismic waves for later analysis. Though some large-scale structures can often be perceived from a direct examination of the recorded signals, the recorded signals must be processed to remove distortion and reveal finer detail in the subsurface image. Among the available processing techniques for marine seismic surveys is a regularization technique to remove azimuthal effects on the seismic traces. As described by Michel Schonewille in “Regularization with azimuth time-shift correction”, SEG 2003, regularization eliminates survey artifacts due to the effect of azimuthal differences that arise when small navigational changes in position and direction occur. However, it has been discovered that the performance of some regularization algorithms is sensitive to the interpolation technique employed beforehand, and that existing interpolation techniques can be inadequate or expensive.
While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the drawings and detailed description thereto are not intended to limit the invention to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the present invention as defined by the appended claims.
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