Spectral decomposition for seismic interpretation

A method for the exploration of hydrocarbons, comprising the steps of:

• (a) obtaining a representation of a set of spatially related seismic traces distributed over a pre-determined volume of the earth, said seismic traces containing digital samples, said digital samples being characterized by at least a time, a position, and an amplitude;
• (b) selecting a part of said volume and the spatially related seismic traces contained therein to define a zone of interest within said volume;
• (c) defining a window within said zone of interest, said window having a starting sample number and encompassing digital samples;
• (d) transforming at least a portion of said spatially related seismic traces within said zone of interest using a discrete orthonormal transformation, said discrete orthonormal transformation
• (i) being characterized by a plurality of orthonormal basis functions, and
• (ii) being applied to a window containing said digital samples to produce a plurality of transform coefficients associated with said orthonormal basis functions;
• (e) organizing said transform coefficients into a tuning cube, said tuning cube and the transform coefficients therein being associated with said starting sample number;
• (f) repeating steps (c) and (d) for a plurality of window definitions, thereby producing a plurality of tuning cubes;
• and,
• (g) displaying one or more of said plurality of tuning cubes.

In the exploration for hydrocarbons, a seismic attribute map prepared by a process, said process comprising the steps of:

• (a) accessing by means of a computer, a data set comprising seismic traces distributed over a pre-determined volume of the earth, said seismic traces containing digital samples, said digital samples being characterized by at least a time, a position, and an amplitude;
• (b) selecting a plurality of spatially related seismic traces from said seismic trace data set;
• (c) selecting a zone of interest within said selected plurality of spatially related seismic traces;
• (d) transforming at least a portion of said spatially related seismic traces within said zone of interest using a discrete orthonormal transformation, said discrete orthonormal transformation producing transform coefficients from said spatially related seismic traces so transformed;
• and,
• (e) organizing said transform coefficients into a tuning cube;
• (f) calculating a plurality of seismic attribute values from said transform coefficients organized into said tuning cube;
• and,
• (g) displaying said seismic attribute values at locations representative of said positions.

A method for the generation of seismic attributes for use in the exploration of hydrocarbons, comprising the steps of:

• (a) obtaining a representation of a set of seismic traces distributed over a pre-determined volume of the earth, said seismic traces containing samples, said samples being characterized by at least a time, a position, and an amplitude;
• (b) selecting a part of said volume and the seismic traces contained therein to define a zone of interest within said volume;
• (c) transforming at least a portion of said seismic traces within said zone of interest using a discrete orthonormal transformation, said very short time discrete orthonormal transformation producing transform coefficients;
• (d) organizing said transform coefficients into a tuning cube;
• and,
• (e) calculating, from said tuning cube, a plurality of seismic attributes.

A computer based method of filtering geophysical time series, comprising the steps of:

• (a) obtaining a representation of a set of spatially related seismic traces distributed over a pre-determined volume of the earth, said spatially related seismic traces containing digital samples, said digital samples being characterized by at least a time, a position, and an amplitude;
• (b) selecting a part of said volume and the spatially related seismic traces contained therein to define a zone of interest within said volume;
• (c) transforming at least a portion of said spatially related seismic traces within said zone of interest using a discrete orthonormal transformation, said discrete orthonormal transformation producing transform coefficients from said spatially related seismic traces so transformed;
• and,
• (d) organizing said transform coefficients into a tuning cube;
• (e) scaling said transform coefficients within said tuning cube;
• and,
• (f) inverting said tuning cube using a discrete orthonormal transformation inverse, thereby producing a filtered version of said transformed portion of said spatially related seismic traces.

In a digital computer wherein seismic traces obtained over a pre-determined volume of the earth are read into memory, wherein a plurality of spatially related seismic traces are selected from said seismic traces, and wherein a zone of interest within said spatially related seismic traces has been defined, a digital computer programmed to perform a process comprising the steps of:

• (a) transforming at least a portion of said spatially related seismic traces within said zone of interest using a discrete orthonormal transformation, said discrete orthonormal transformation producing transform coefficients from said spatially related seismic traces so transformed;
• (b) organizing said transform coefficients into a tuning cube;
• (c) scaling said transform coefficients within said tuning cube;
• and,
• (d) inverting said tuning cube using a discrete orthonormal transformation inverse, thereby producing a filtered version of said transformed portion of said spatially related seismic traces.