A METHOD OF PROCESSING SEISMIC DATA SIGNALS

摘要

1. A method of processing seismic data signals reflected by a particular subsurface feature, the method comprising analysis of the spectrum of the seismic data signals by decomposing the reflected signals with respect to a series of orthogonal polynomials and deriving a series of polynomial coefficients which characterise the reflectivity of the subsurface feature. 2. A method as claimed in claim 1, wherein the subsurface feature comprises a layer defined by two horizons and the series of polynomial coefficients represents a volume spectral analysis. 3. A method as claimed in claim 1, wherein the subsurface feature comprises a horizon. 4. A method as claimed in any one of the preceding claims, wherein the set of orthogonal polynomials comprises a set of Chebyshev polynomials. 5. A method as claimed in any one of the preceding claims, further comprising a comparison between the characterised subsurface feature and a plurality of predetermined characterisations of subsurface features, wherein the closest match between the characterised feature and a predetermined characterisation is determined. 6. A method as claimed in claim 5, wherein the predetermined characterisation having the closest match to the characterised feature is determined using a least squares fit. 7. A method as claimed in claim 5 or claim 6, wherein a predetermined characterisation having the closest match is perturbed to provide at least one further predetermined characterisation for comparison with the characterised feature. 8. A method as claimed in claim 1, further comprising the calculation of an additional attribute of the seismic data signals using the derived polynomial coefficients. 9. A method as claimed in claim 8, wherein the additional attribute comprises a number, sign, magnitude or location of extremal values of a reconstructed trace generated by summing the derived polynomial coefficients multiplied by their respective orthogonal polynomial functions. 10. A method as claimed in claim8 further comprising the remote sensing of geologic or subsurface features by observing changes in the derived polynomial characteristics or the additional attribute. 11. A method as claimed in claim 8, wherein the additional attribute represents an internal reflector within a layer.