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US 11,143,774 B2Granted
Method and system for separating blended seismic data
AssigneeShell Oil Company
InventorsYing Ji, Zijian Tang, Guido Jozef Maria Baeten
Life of this patent
Estimating the term…
Abstract
Simultaneous sources are separated with a deblending method wherein the fullband data deblended on a source-by-source basis. The fullband data is first decomposed into multiple subbands, and then a non-equispaced subband Radon transform is used to transform the decomposed data into the Radon domain. The deblending process is solved subband by subband by minimising a nonlinear objective function. The solution of the nonlinear objective function is found using a multi-step procedure.
Claims30
A method for separating blended seismic data containing overlapping data responses to interfering seismic waves generated by a plurality of sources, comprising:
- (a) providing a fullband gather for a receiver, which fullband gather is one of the group consisting of a common receiver gather, a common midpoint gather and a common offset gather, which fullband gather comprises a set of blended traces that contain seismic signals representing energy received from a plurality of clusters, each of which clusters comprising multiple sources overlapping in time-frequency domain, wherein each source represents seismic energy that is released in the earth by one group of vibrators defined such that none of the vibrators within said one group is overlapping in time-frequency domain with any other source within the same one group, and wherein each vibrator within a single cluster of said plurality of clusters is uniquely located at its own unique position vector with respect to the receiver and fired at a known firing time;
- (b) creating one or more single source gathers by iteratively separating signals of one or more selected single sources from the fullband gather, wherein performing steps b1 to b6:
- (b1) selecting one source from the multiple sources of one cluster of said plurality of clusters;
- (b2) creating an intermediate fullband gather by subtracting from the set of blended traces of the fullband gather signals of all sources from other clusters of said plurality of clusters, which have already been separated from the fullband gather in earlier iterations of performing steps b1 to b7, thereby obtaining the intermediate fullband gather consisting of intermediate blended traces;
- (b3) unless the intermediate fullband gather is already source-aligned to the selected source, source-aligning the intermediate fullband gather of step b2 by cutting the blended traces in the intermediate fullband gather such that each intermediate blended trace in the intermediate fullband gather is cut to start at a time zero coincident with the firing time of the vibrator belonging to the unique position vector of the blended trace associated with that source;
- (b4) creating multiple subband gathers from the intermediate fullband gather by decomposing the source-aligned fullband gather from b3 into frequency subbands;
- (b5) for each subband gather of the multiple subband gathers from b4 separating the signal corresponding to the one source selected in step b1 thereby creating one separated single source subband gather, by performing steps b5.1 to b5.3 until all subband gathers from the multiple subband gathers are processed;
- (b5.1) one after another selecting one subband gather from the multiple subband gathers, computing non-equispaced Radon coefficients, and computing orthogonal projections of selected Radon coefficients within the selected subband gather by iteratively performing steps b5.1.1 to b5.1.5 whereby minimizing an objective function until a pre-defined first stop-criterion is met;
- (b5.1.1) creating an intermediate subband gather by subtracting orthogonal projections that have already been obtained while performing steps b5.1.2 to b5.1.5 from the selected subband gather;
- (b5.1.2) computing estimated Radon coefficients of the intermediate subband gather from step b5.1 by transforming the intermediate subband gather into a Radon domain using a non-equispaced Radon transformation, thereby producing a collection of estimated Radon coefficients;
- (b5.1.3) selecting a number of the estimated Radon coefficients, wherein each of the selected estimated Radon coefficients have a higher amplitude than each of the non-retained estimated Radon coefficients within the collection of estimated Radon coefficients;
- (b5.1.4) computing orthogonal projections of exclusively the selected estimated Radon coefficients from step b5.1.3;
- (b5.1.5) going back to step b5.1.1 until the pre-defined first stop-criterion is met;
- (b5.2) creating the separated single source subband gathers by recalculating the orthogonal projections by interpolating to a regular grid of source positions;
- (b5.3) going back to step b5.1 until all subband gathers from the multiple subband gathers are processed;
- (b6) creating the one or more single source gathers in fullband by reconstructing the fullband gather from the separated single source subband gathers.
13 more elements
A system for separating blended seismic data containing overlapping data responses to interfering seismic waves generated by a plurality of sources, comprising:
- a non-transitory computer readable storage medium on which is stored a fullband gather for a receiver, which fullband gather is one of the group consisting of a common receiver gather, a common midpoint gather and a common offset gather, which fullband gather comprises a set of blended traces that contain seismic signals representing energy received from a plurality of clusters, each of which clusters comprising multiple sources overlapping in time-frequency domain, wherein each source represents seismic energy that is released in the earth by one group of vibrators defined such that none of the vibrators within said one group is overlapping in time-frequency domain with any other source within the same one group, and wherein each vibrator within a single cluster of said plurality of clusters is uniquely located at its own unique position vector with respect to the receiver and fired at a known firing time;
- a computer processor operatively coupled to the computer readable storage medium and programmed to create one or more single source gathers by iteratively separating signals of one or more selected single sources from the fullband gather, wherein performing steps b1 to b6:
- (b1) selecting one source from the multiple sources of one cluster of said plurality of clusters;
- (b2) creating an intermediate fullband gather by subtracting from the set of blended traces of the fullband gather signals of all sources from other clusters of said plurality of clusters, which have already been separated from the fullband gather in earlier iterations of performing steps b1 to b7, thereby obtaining the intermediate fullband gather consisting of intermediate blended traces;
- (b3) unless the intermediate fullband gather is already source-aligned to the selected source, source-aligning the intermediate fullband gather of step b2 by cutting the blended traces in the intermediate fullband gather such that each intermediate blended trace in the intermediate fullband gather is cut to start at a time zero coincident with the firing time of the vibrator belonging to the unique position vector of the blended trace associated with that source;
- (b4) creating multiple subband gathers from the intermediate fullband gather by decomposing the source-aligned fullband gather from b3 into frequency subbands;
- (b5) for each subband gather of the multiple subband gathers from b4 separating the signal corresponding to the one source selected in step b1 thereby creating one separated single source subband gather, by performing steps b5.1 to b5.3 until all subband gathers from the multiple subband gathers are processed;
- (b5.1) one after another selecting one subband gather from the multiple subband gathers, computing non-equispaced Radon coefficients, and computing orthogonal projections of selected Radon coefficients within the selected subband gather by iteratively performing steps b5.1.1 to b5.1.5 whereby minimizing an objective function until a pre-defined first stop-criterion is met;
- (b5.1.1) creating an intermediate subband gather by subtracting orthogonal projections that have already been obtained while performing steps b5.1.2 to b5.1.5 from the selected subband gather;
- (b5.1.2) computing estimated Radon coefficients of the intermediate subband gather from step b5.1 by transforming the intermediate subband gather into a Radon domain using a non-equispaced Radon transformation, thereby producing a collection of estimated Radon coefficients;
- (b5.1.3) selecting a number of the estimated Radon coefficients, wherein each of the selected estimated Radon coefficients have a higher amplitude than each of the non-retained estimated Radon coefficients within the collection of estimated Radon coefficients;
- (b5.1.4) computing orthogonal projections of exclusively the selected estimated Radon coefficients from step b5.1.3;
- (b5.1.5) going back to step b5.1.1 until the pre-defined first stop-criterion is met;
- (b5.2) creating the separated single source subband gathers by recalculating the orthogonal projections by interpolating to a regular grid of source positions;
- (b5.3) going back to step b5.1 until all subband gathers from the multiple subband gathers are processed;
- (b6) creating the one or more single source gathers in fullband by reconstructing the fullband gather from the separated single source subband gathers;
- and
- an output device operatively coupled to the computer processor and configured to output the one or more single source gathers created in step b6.
15 more elements
A method for separating blended seismic data containing overlapping data responses to interfering seismic waves generated by a plurality of sources, comprising:
- (a) providing a fullband gather for a receiver, which fullband gather is one of the group consisting of a common receiver gather, a common midpoint gather and a common offset gather, which fullband gather comprises a set of blended traces that contain seismic signals representing energy received from a cluster comprising multiple sources overlapping in time-frequency domain, wherein each source represents seismic energy that is released in the earth by one group of vibrators defined such that none of the vibrators within said one group is overlapping in time-frequency domain with any other source within the same one group, and wherein each vibrator within a single cluster of said plurality of clusters is uniquely located at its own unique position vector with respect to the receiver and fired at a known firing time;
- (b) creating one or more single source gathers by iteratively separating signals of one or more selected single sources from the fullband gather, wherein performing steps b1 to b6:
- (b1) selecting one source from the multiple sources of the cluster;
- (b2) proceeding to step b3;
- (b3) unless the fullband gather is already source-aligned to the selected source, source-aligning the fullband gather by cutting the blended traces in the fullband gather such that each blended trace in the fullband gather is cut to start at a time zero coincident with the firing time of the vibrator belonging to the unique position vector of the blended trace associated with that source;
- (b4) creating multiple subband gathers from the fullband gather by decomposing the source-aligned fullband gather from b3 into frequency subbands;
- (b5) for each subband gather of the multiple subband gathers from b4 separating the signal corresponding to the one source selected in step b1 thereby creating one separated single source subband gather, by performing steps b5.1 to b5.3 until all subband gathers from the multiple subband gathers are processed;
- (b5.1) one after another selecting one subband gather from the multiple subband gathers, computing non-equispaced Radon coefficients, and computing orthogonal projections of selected Radon coefficients within the selected subband gather by iteratively performing steps b5.1.1 to b5.1.5 whereby minimizing an objective function until a pre-defined first stop-criterion is met;
- (b5.1.1) creating an intermediate subband gather by subtracting orthogonal projections that have already been obtained while performing steps b5.1.2 to b5.1.5 from the selected subband gather;
- (b5.1.2) computing estimated Radon coefficients of the intermediate subband gather from step b5.1 by transforming the intermediate subband gather into a Radon domain using a non-equispaced Radon transformation, thereby producing a collection of estimated Radon coefficients;
- (b5.1.3) selecting a number of the estimated Radon coefficients, wherein each of the selected estimated Radon coefficients have a higher amplitude than each of the non-retained estimated Radon coefficients within the collection of estimated Radon coefficients;
- (b5.1.4) computing orthogonal projections of exclusively the selected estimated Radon coefficients from step b5.1.3;
- (b5.1.5) going back to step b5.1.1 until the pre-defined first stop-criterion is met;
- (b5.2) creating the separated single source subband gathers by recalculating the orthogonal projections by interpolating to a regular grid of source positions;
- (b5.3) going back to step b5.1 until all subband gathers from the multiple subband gathers are processed;
- (b6) creating the one or more single source gathers in fullband by reconstructing the fullband gather from the separated single source subband gathers.
13 more elements
A system for separating blended seismic data containing overlapping data responses to interfering seismic waves generated by a plurality of sources, comprising:
- a non-transitory computer readable storage medium on which is stored a fullband gather for a receiver, which fullband gather is one of the group consisting of a common receiver gather, a common midpoint gather and a common offset gather, which fullband gather comprises a set of blended traces that contain seismic signals representing energy received from a plurality of clusters, each of which clusters comprising multiple sources overlapping in time-frequency domain, wherein each source represents seismic energy that is released in the earth by one group of vibrators defined such that none of the vibrators within said one group is overlapping in time-frequency domain with any other source within the same one group, and wherein each vibrator within a single cluster of said plurality of clusters is uniquely located at its own unique position vector with respect to the receiver and fired at a known firing time;
- a computer processor operatively coupled to the computer readable storage medium and programmed to create one or more single source gathers by iteratively separating signals of one or more selected single sources from the fullband gather, wherein performing steps b1 to b6:
- (b1) selecting one source from the multiple sources of one cluster of said plurality of clusters;
- (b2) proceeding to b3;
- (b3) unless the fullband gather is already source-aligned to the selected source, source-aligning the fullband gather of step b2 by cutting the blended traces in the fullband gather such that each intermediate blended trace in the fullband gather is cut to start at a time zero coincident with the firing time of the vibrator belonging to the unique position vector of the blended trace associated with that source;
- (b4) creating multiple subband gathers from the fullband gather by decomposing the source-aligned fullband gather from b3 into frequency subbands;
- (b5) for each subband gather of the multiple subband gathers from b4 separating the signal corresponding to the one source selected in step b1 thereby creating one separated single source subband gather, by performing steps b5.1 to b5.3 until all subband gathers from the multiple subband gathers are processed;
- (b5.1) one after another selecting one subband gather from the multiple subband gathers, computing non-equispaced Radon coefficients, and computing orthogonal projections of selected Radon coefficients within the selected subband gather by iteratively performing steps b5.1.1 to b5.1.5 whereby minimizing an objective function until a pre-defined first stop-criterion is met;
- (b5.1.1) creating an intermediate subband gather by subtracting orthogonal projections that have already been obtained while performing steps b5.1.2 to b5.1.5 from the selected subband gather;
- (b5.1.2) computing estimated Radon coefficients of the intermediate subband gather from step b5.1 by transforming the intermediate subband gather into a Radon domain using a non-equispaced Radon transformation, thereby producing a collection of estimated Radon coefficients;
- (b5.1.3) selecting a number of the estimated Radon coefficients, wherein each of the selected estimated Radon coefficients have a higher amplitude than each of the non-retained estimated Radon coefficients within the collection of estimated Radon coefficients;
- (b5.1.4) computing orthogonal projections of exclusively the selected estimated Radon coefficients from step b5.1.3;
- (b5.1.5) going back to step b5.1.1 until the pre-defined first stop-criterion is met;
- (b5.2) creating the separated single source subband gathers by recalculating the orthogonal projections by interpolating to a regular grid of source positions;
- (b5.3) going back to step b5.1 until all subband gathers from the multiple subband gathers are processed;
- (b6) creating the one or more single source gathers in fullband by reconstructing the fullband gather from the separated single source subband gathers;
- and
- an output device operatively coupled to the computer processor and configured to output the one or more single source gathers created in step b6.
15 more elements
Dependencies are inferred from the claim text.