초록 ▼

The instant invention pertains generally to a method of seismic processing of multi-component converted wave 2-D and 3-D seismic data, wherein the seismic traces in each CCP gather may have been acquired at a variety of different source-receiver azimuths. According to one aspect of the instant inven

The instant invention pertains generally to a method of seismic processing of multi-component converted wave 2-D and 3-D seismic data, wherein the seismic traces in each CCP gather may have been acquired at a variety of different source-receiver azimuths. According to one aspect of the instant invention there is provided a method of using recorded multi-component seismic data to determine an estimate of the orientation of the two principle coordinate axes of a subsurface medium, with this determination potentially being made in each seismic survey bin, and for each depth. Given this estimate, the seismic data may then be transformed via rotation into the coordinate system so defined, and thereafter processed using conventional algorithms (e.g., to produce velocity functions and images). Another embodiment of the instant invention uses a given principle coordinate axis orientation--which might have been obtained via the previous embodiment--to calculate a "best" data reduction of the traces in the CCP. In either case, the present invention additionally solves the problem of deducing the principal times series and provides a means of combining multi-azimuth multi-component CCP gathers for further conventional scalar processing. Those skilled in the art will appreciate that the methods disclosed below would be especially useful in 3-D surveys and in 2-D crooked line surveys.

대표청구항 ▼

[ What is claimed is:] [19.]19. A method of seismic exploration for hydrocarbons within a predetermined volume of the earth containing structural and stratigraphic features, said predetermined volume of the earth being characterized by at least one subsurface velocity,wherein there is provided a sei

[ What is claimed is:] [19.]19. A method of seismic exploration for hydrocarbons within a predetermined volume of the earth containing structural and stratigraphic features, said predetermined volume of the earth being characterized by at least one subsurface velocity,wherein there is provided a seismic survey consisting of unstacked multi-component CCP gathers collected over said predetermined volume of the earth,at least one of said multi-component CCP gathers being comprised of at least four unstacked CCP traces,each of said at least four unstacked CCP traces spanning a plurality of time levels, and,each of said four or more unstacked CCP traces having at least a shot-receiver azimuth and a shot offset associated therewith, andwherein there is a provided a velocity model that is at least approximately representative of said at least one subsurface velocity within at least a portion of said predetermined volume of the earth,(a) selecting a particular CCP gather having at least four unstacked CCP traces associated therewith from among said at least one multi-component CCP gathers;(b) selecting a time level spanned by said at least four unstacked CCP traces;(c) obtaining a generalized inverse of an effective source/propagation matrix associated with said selected time level;(d) multiplying said particular CCP gather by said generalized inverse of said effective source orientation matrix for at least said selected time level, thereby obtaining at least one product matrix;(e) performing steps (b) through (d) a plurality of times, thereby forming a plurality of product matrices; and,(f) organizing said plurality of product matrices into a synthesized CCP gather for use in the identification of said structural and stratigraphic features within said predetermined volume of the earth.