Source signature determination and multiple reflection reduction
AssigneeSchlumberger Technology Corporation
InventorsLuc Thomas Ikelle, Graham Roberts
Life of this patent
Estimating the term…
Abstract
The signature of an energy source is determined from an inverse scattering Born series representing multiple reflected energy. The series comprises a polynomial in the inverse of the signature and has recorded data as the first term. The series is truncated, preferably to the first two terms to permit an analytical determination of the signature to be found. The value of the inverse signature which minimises the energy represented by the sub-series is found and this corresponds to the desired source signature. An iterative scheme may be adopted to improve the match to the actual signature so as to take into account the errors caused by truncating the scattering series.
Claims11
A method of estimating a wavelet representing output from an energy source comprising:
- constructing an inverse scattering series which represents multiple reflected energy and which comprises a polynomial in an inverse of a source signature and has recorded data as the first term thereof;
- selecting a sub-series comprising two terms of the inverse scattering series, the two terms comprising the first term and an Nth order term where N is a positive integer;
- and
- estimating a value of the inverse signature which substantially minimizes the energy represented by the sub-series.
A method of estimating a wavelet representing output from a marine seismic energy source comprising:
- constructing an inverse scattering series which represents multiple reflected energy and which comprises a polynomial in an inverse of the signature and has recorded marine seismic data as the first term thereof;
- selecting a sub-series comprising two terms of the inverse scattering series, the two terms comprising the first term and the Nth order term where N is a positive integer equal to 2;
- and
- estimating a value of the inverse signature which substantially minimizes the energy represented by the sub-series, comprising analytically solving an expression for energy minimization of the sub-series to determine the inverse signature.
A method of determining a signature of an energy source comprising:
- constructing an inverse scattering series which represents multiple reflected energy and which comprises a polynomial in an inverse of the signature and has recorded data as the first term thereof;
- selecting a sub-series comprising two terms of the inverse scattering series, the two terms comprising the first term and an Nth order term where N is a positive integer;
- and
- determining a value of the inverse signature which substantially minimizes the energy represented by the sub-series and wherein the recorded data comprise transformed recorded data.
A method of determining a signature of an energy source comprising:
- constructing an inverse scattering series which represents multiple reflected energy and which comprises a polynomial in an inverse of the signature and has recorded data as the first term thereof;
- selecting a sub-series comprising two terms of the inverse scattering series, the two terms comprising the first term and an Nth order term where N is a positive integer;
- and
- determining a value of the inverse signature which substantially minimizes the energy represented by the sub-series, in which the recorded data comprise marine seismic data.
Dependencies are inferred from the claim text.