Claims
- 1. A method for determining from measured reflection data on a plurality of trace positions one or more subsurface parameters, said method comprising the steps of:
(a) preprocessing the measured reflection data into a plurality of partial or full stacks; (b) specifying one or more initial subsurface parameters defining an initial subsurface model; (c) specifying a wavelet or wavelet field for each of the partial or full stacks of the measured reflection data; (d) calculating synthetic reflection data based on the specified wavelets and the initial subsurface parameters; (e) optimizing an objective function, comprising the weighted difference between measured reflection data and synthetic reflection data for a plurality of trace positions simultaneously; and (f) outputting the optimized one or more subsurface parameters.
- 2. The method according to claim 1, wherein the step of optimizing the objective function comprises minimizing the objective function:
- 3. The method according to claim 2, wherein the objective function comprises one or more stabilization terms and/or one or more correction terms.
- 4. The method according to claim 3, wherein a stabilization term is a measure for the deviation of the reflectivity away from 0.
- 5. The method according to claim 4, wherein said measure comprises
- 6. The method according to claim 3, wherein a stabilization term is a measure for the parameter contrast.
- 7. The method according to claim 6, wherein said measure comprises
- 8. The method according to claim 3, wherein a stabilization term is a measure for the deviation of the subsurface parameters from the initial subsurface parameters.
- 9. The method according to claim 8, wherein said measure comprises
- 10. The method according to claim 7, wherein a stabilization term is a measure for the deviation of the calculated subsurface parameters from a priori specified functional relationships between subsurface parameters.
- 11. The method according to claim 10, wherein said measure comprises
- 12. The method according to claim 3, wherein a stabilization term is a measure for the lateral variability of the parameters.
- 13. The method according to claim 12, wherein said measure comprises
- 14. The method according to claim 13, wherein the parameter difference dj,l,n is defined as
- 15. The method according to claim 1, wherein a correction term is a measure for the differential time shifts between traces of measured reflection data stacks.
- 16. The method according to claim 15, wherein said measure comprises
- 17. The method according to claim 1, wherein a stabilization term is a measure for the parameter differences between reflection data acquisition surveys taken at different points in time.
- 18. The method according to claim 17, wherein said measure comprises
- 19. The method according to claim 1, wherein constraints and/or constraint functions are applied to one or more of the subsurface parameters; and/or are applied to control changes of subsurface parameters between surveys taken on different times; and/or constrain outside a specified subsurface zone the parameter changes between surveys to small values relative to changes expected within the specified subsurface zone; and/or constrain the minimization by setting the subsurface parameters outside a specified subsurface zone from survey to survey at the same value.
- 20. The method according to claim 1, wherein for optimizing the objective function outside a specified subsurface zone only one or one set of different subsurface parameters are specified.
- 21. The method according to claim 1, comprising the generation of quality control information.
- 22. The method according to claim 21, wherein the quality information includes at least one of: (i) synthetic data based on the optimized subsurface parameters; (ii) residual data obtained by subtracting the synthetic data from the measured reflection data; (iii) deviation data obtained by determining the deviations away from the initial subsurface parameters; (iv) deviation data obtained by determining the deviations away from the corresponding functional relations; and (v) deviation data obtained by determining the deviations away from well log data.
- 23. The method according to claim 1, wherein the reflection data is at least one of seismic data and time lapse data.
- 24. The method according to claim 1, wherein the subsurface parameters comprise elastic parameters.
- 25. The method according to claim 24, wherein the elastic parameters comprise pressure wave velocities and/or shear wave velocities and/or densities in the subsurface and/or the subsurface parameters comprise any mathematical relation between pressure wave velocities and/or shear wave velocities, and/or densities.
- 26. The method according to claim 1, wherein the subsurface parameters comprise compositional parameters representing the rock and fluid composition of the subsurface.
- 27. The method according to claim 25, wherein the seismic data comprises at least two seismic partial or full stacks containing different angle dependant information on seismic reflections in the subsurface.
- 28. The method according to claim 23, wherein the time lapse data at each survey time comprises at least one seismic partial or full stack.
- 29. The method according to claim 2, wherein the adjustable norm LP of a variable x for variable x comprises
- 30. The method according to claim 29, wherein the norm LP is normalized by or with at least one of: (i) exponentiation with 1/P; (ii) the number of samples; and (iii) the square root of the variance of x.
- 31. The method according to claim 23, wherein the seismic reflection data is determined from at least one of the following source-receiver combinations:
P-wave source and P-wave receiver, P-wave source and S-wave receiver, S-wave source and P-wave receiver, S-wave source and S-wave receiver.
- 32. The method according to claim 1, wherein the reflection data is echo-acoustic data and the subsurface is human or mammal tissue or any other material.
- 33. A method for determining from measured reflection data on one or more trace positions a plurality of subsurface parameters, said method comprising the steps of:
(a) preprocessing the measured reflection data into a plurality of partial or full stacks; (b) specifying a plurality of initial subsurface parameters defining an initial subsurface model; (c) specifying a wavelet or wavelet field for each of the partial or full stacks of the measured reflection data; (d) calculating synthetic reflection data based on the specified wavelets and the initial subsurface parameters; (e) simultaneously optimizing an objective function, comprising the weighted difference between measured reflection data and synthetic reflection data, for said plurality of subsurface parameters and for each trace position separately; and (g) outputting said plurality of optimized subsurface parameters.
- 34. The method according to claim 33, wherein the step of optimizing the objective function comprises minimizing the objective function:
- 35. The method according to claim 33, wherein the objective function comprises one or more stabilization terms and/or one or more correction terms.
- 36. The method according to claim 35, wherein a stabilization term is a measure for the deviation of the reflectivity away from 0.
- 37. The method according to claim 36, wherein said measure comprises
- 38. The method according to claim 35, wherein a stabilization term is a measure for the parameter contrast.
- 39. The method according to claim 38, wherein said measure comprises
- 40. The method according to claim 35, wherein a stabilization term is a measure for the deviation of the subsurface parameters from the initial subsurface parameters.
- 41. The method according to claim 40, wherein said measure comprises
- 42. The method according to claim 39, wherein a stabilization term is a measure for the deviation of the calculated subsurface parameters from a priori specified functional relationships between subsurface parameters.
- 43. The method according to claim 42, wherein said measure comprises
- 44. The method according to claim 35, wherein a stabilization term is a measure for the lateral variability of the parameters.
- 45. The method according to claim 44, wherein said measure comprises
- 46. The method according to claim 45, wherein the parameter difference dj,l,n is defined as
- 47. The method according to claim 33, wherein a correction term is a measure for the differential time shifts between traces of measured reflection data stacks.
- 48. The method according to claim 47, wherein said measure comprises
- 49. The method according to claim 33, wherein a stabilization term is a measure for the parameter differences between reflection data acquisition surveys taken at different points in time.
- 50. The method according to claim 49, wherein said measure comprises
- 51. The method according to claim 33, wherein constraints and/or constraint functions are applied to one or more of the subsurface parameters; and/or are applied to control changes of subsurface parameters between surveys taken on different times; and/or constrain outside a specified subsurface zone the parameter changes between surveys to small values relative to changes expected within the specified subsurface zone; and/or constrain the minimization by setting the subsurface parameters outside a specified subsurface zone from survey to survey at the same value.
- 52. The method according to claim 33, wherein for optimizing the objective function outside a specified subsurface zone only one or one set of different subsurface parameters are specified.
- 53. The method according to claim 33, comprising the generation of quality control information.
- 54. The method according to claim 53, wherein the quality information includes at least one of: (i) synthetic data based on the optimized subsurface parameters; (ii) residual data obtained by subtracting the synthetic data from the measured reflection data; (iii) deviation data obtained by determining the deviations away from the initial subsurface parameters; (iv) deviation data obtained by determining the deviations away from the corresponding functional relations; and (v) deviation data obtained by determining the deviations away from well log data.
- 55. The method according to claim 33, wherein the reflection data is at least one of seismic data and time lapse data.
- 56. The method according to claim 33, wherein the subsurface parameters comprise elastic parameters.
- 57. The method according to claim 56, wherein the elastic parameters comprise pressure wave velocities and/or shear wave velocities and/or densities in the subsurface and/or the subsurface parameters comprise any mathematical relation between pressure wave velocities and/or shear wave velocities and/or densities.
- 58. The method according to claim 33, wherein the subsurface parameters comprise compositional parameters representing the rock and fluid composition of the subsurface.
- 59. The method according to claim 57, wherein the seismic data comprises at least two seismic partial or full stacks containing different angle dependant information on seismic reflections in the subsurface.
- 60. The method according to claim 55, wherein the time lapse data at each survey time comprises at least one seismic partial or full stack.
- 61. The method according to claim 34, wherein the adjustable norm LP of a variable x for variable x comprises
- 62. The method according to claim 61, wherein the norm LP is normalized by or with at least one of: (i) exponentiation with 1/P; (ii) the number of samples; and (iii) the square root of the variance of x.
- 63. The method according to claim 35, wherein the seismic reflection data is determined from at least one of the following source-receiver combinations:
P-wave source and P-wave receiver, P-wave source and S-wave receiver, S-wave source and P-wave receiver, S-wave source and S-wave receiver.
- 64. The method according to claim 33, wherein the reflection data is echo-acoustic data and the subsurface is human or mammal tissue or any other material.
- 65. A device for determining from measured reflection data on a plurality of trace positions one or more subsurface parameters, the device comprising:
(a) input means for inputting at least the measured reflection data and one or more initial subsurface parameters defining an initial subsurface model; (b) processing means for:
(i) preprocessing the measured reflection data into a plurality of partial or full stacks; (ii) specifying a wavelet or wavelet or wavelet field for each of the partial or full stacks of the measured reflection data; (iii) calculating synthetic reflection data based on the specified wavelets or wavelet fields and the initial subsurface parameters; and (iv) (a) optimizing an objective function, comprising the weighted difference between measured reflection data and synthetic reflection data for a plurality of trace positions simultaneously; or (b) optimizing an objective function, comprising the weighted difference between measured reflection data and synthetic reflection data for a plurality of trace positions simultaneously and one or more stagilization terms and/or one or more correction terms; and (c) output means for outputting optimized one or more subsurface parameters.
- 66. A device for determining from measured reflection data on one or more trace positions a plurality of subsurface parameters, said device comprising:
(a) input means for inputting at least the measured reflection data and one or more initial subsurface parameters defining an initial subsurface model; (b) processing means for:
(i) preprocessing the measured reflection data into a plurality of partial or full stacks; (ii) specifying a wavelet or wavelet field for each of the partial or full stacks of the measured reflection data; (iii) calculating synthetic reflection data based on the specified wavelets or wavelet fields and the initial subsurface parameters; and (iv) (a) simultaneously optimizing an objective function, comprising the weighted difference between measured reflection data and synthetic reflection data, for said plurality of subsurface parameters and for each trace position separately; and (b) optimizing an objective function, comprising the weighted difference between measured reflection data and synthetic reflection data for a plurality of trace positions simultaneously and one or more stabilization terms and/or one or more correction terns; and (c) output means for outputting optimized subsurface parameters.
Priority Claims (1)
Number |
Date |
Country |
Kind |
99 203 477.7 |
Oct 1998 |
EP |
|
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent application Ser. No. 09/817,807 filed Mar. 26, 2001, which is a continuation of International Patent Application Number PCT/EP00/10464, filed Oct. 23, 2000, and designating, inter alia, the United States, which claims priority to European Application No. 99203477.7, filed Oct. 22, 1999.
Continuations (2)
|
Number |
Date |
Country |
Parent |
09817807 |
Mar 2001 |
US |
Child |
10672751 |
Sep 2003 |
US |
Parent |
PCT/EP00/10464 |
Oct 2000 |
US |
Child |
09817807 |
Mar 2001 |
US |