Method of processing seismic data and method of producing a mineral hydrocarbon fluid and a computer program product

1. A method of increasing the resolution of an image produced from seismic data, the method comprising the steps of:

(a) providing an input digital seismic trace comprising at least one seismic loop;

(b) on a computer, obtaining a selected discrete wavelet transform of the first digital seismic trace, as a function of scale s j and shifted sample time t k ;

(c) on a computer, obtaining a singularity spectrum from the discrete wavelet transform for each seismic loop;

(d) on a computer, estimating from the singularity spectrum at least two subsurface scaling parameters that are controlled exclusively by earth properties and at least one parameter associated with a seismic wavelet;

(e) on a computer, fitting to the singularity spectrum a selected analytic function that depends on said at least two subsurface scaling parameters and said parameter associated with a seismic wavelet

(f) on a computer, removing the seismic wavelet parameter and using the subsurface scaling parameters to construct wavelet transforms at scales lower than that found in the input seismic trace;

(g) on a computer, inverse transforming the wavelet transform constructed in step (f) to obtain a second seismic trace having a higher resolution than the input seismic trace.

2. The method of claim 1 , wherein the parameter associated with the seismic wavelet comprises a width a of the seismic wavelet.

3. The method of claim 1 , wherein step (a) comprises providing an original digital seismic trace and resampling the original digital seismic trace to a higher sampling density to obtain the input digital seismic trace.

4. The method of claim 3 , wherein resampling comprises interpolating the original digital seismic trace to increase a sampling density.

5. The method of claim 3 , wherein the sampling density is increased by a factor of 2 or more.

6. The method of claim 1 , wherein the scale s j is finer than dyadic.

7. The method of claim 6 , wherein the scale s j is formed by an integer number for each j.

8. The method of claim 1 , wherein step (c) comprises obtaining a value of a local extreme in the wavelet transform at various values of s j .

9. The method of claim 8 , further comprising step

(c1) obtaining a phase spectrum derived from values of t k at which the local extreme is found for the various values of s j .

10. The method of claim 1 , further comprising the steps:

(h) providing plurality of digital seismic traces each comprising at least one seismic loop, the plurality of digital seismic traces forming a seismic line or seismic volume;

(i) repeating (b) to (g) for each of the plurality of digital seismic traces.

11. The method of claim 1 , wherein the singularity spectrum associated with a selected seismic event represent the modulus of a local extremum of a wavelet amplitude in the wavelet transformed seismic trace.

12. The method of claim 1 , wherein at least two of the independent parameters are controlled exclusively by earth properties, and step (g) includes

calculating a reconstructed seismic trace based on the at least two independent parameters that are controlled exclusively by earth properties whereby a contribution of the seismic wavelet is reduced.

13. The method of claim 12 , wherein calculating the reconstructed seismic trace comprises the steps:

(g1) recalculating singularity spectra assuming absence of a contribution of the seismic wavelet;

(g2) combining singularity spectra with phase spectra to recalculate extrema in the wavelet transform;

(g3) performing a spline fit to the recalculated extrema to obtain a spline fitted recalculated wavelet transform;

(g4) inverse transforming the spline fitted recalculated wavelet transform against a congregate of the selected discrete wavelet transform matrix.

14. The method of claim 12 , wherein the reconstructed seismic trace has a bandwidth that is higher than that of the provided digital seismic trace.

15. The method of claim 12 , wherein the reconstructed seismic trace has a bandwidth exceeding 50 Hz.

16. The method of claim 12 , wherein the reconstructed seismic trace has a bandwidth exceeding 2.5 octave.

17. A method of producing a mineral hydrocarbon fluid from an earth formation, the method comprising steps of:

processing seismic data in accordance with the method of claim 1 to obtain processed seismic data;

using the processed seismic data to detect a reservoir in the earth formation, the reservoir containing a mineral hydrocarbon fluid;

producing the mineral hydrocarbon fluid from the reservoir via a well bore that has been drilled into the reservoir.

18. The method of claim 17 , wherein using the processed seismic data comprises correlating the processed seismic data with the presence of a mineral hydrocarbon fluid containing reservoir.

19. The method of claim 17 , further comprising the steps of using the processed seismic data to decide where to drill the well bore and of drilling the well bore.

20. The method of claim 19 , wherein using the processed seismic data further comprises correlating the processed seismic data with the presence of faults.

21. A computer program product comprising software code instructions for performing the steps (b) to (g) of claim 1 , on a digital seismic trace comprising at least one seismic loop, when the computer program product is run on a computer.