EFFICIENT NONLINEAR BEAMFORMING VIA ON-THE-FLY MODEL-SPACE RECONSTRUCTION
A method is disclosed that includes obtaining a seismic data set from a seismic survey conducted over a subterranean region of interest and discretizing the seismic data set into a plurality of sub-regions each with a local traveltime operator. The method further includes dividing the plurality of sub-regions into a first subset and a second subset and calculating the local traveltime operator for each sub-region of the first subset using a conventional method and determining the local traveltime operator for each sub-region of the second subset using a convergent POCS method based on the local traveltime operators for the sub-regions of the first subset. The method further includes determining an enhanced seismic dataset by performing non-linear beamforming using the local traveltime operator for each sub-region of the plurality of sub-regions and determining a location of a hydrocarbon reservoir in the subterranean region of interest using the enhanced seismic data set.
1 . A method, comprising:
obtaining a seismic data set from a seismic survey conducted over a subterranean region of interest;
discretizing the seismic data set into a plurality of sub-regions each with a local traveltime operator;
dividing the plurality of sub-regions into a first subset and a second subset;
calculating the local traveltime operator for each sub-region of the first subset;
determining the local traveltime operator for each sub-region of the second subset using a convergent POCS method based, at least in part, on the local traveltime operators for the sub-regions of the first subset;
determining an enhanced seismic dataset by performing non-linear beamforming using the local traveltime operator for each sub-region of the plurality of sub-regions; and
determining a location of a hydrocarbon reservoir in the subterranean region of interest using the enhanced seismic data set.
2 . The method of claim 1 , further comprising planning a wellbore to penetrate the hydrocarbon reservoir based on the location, wherein the planned wellbore comprises a planned wellbore path.
3 . The method of claim 2 , further comprising drilling the wellbore guided by the planned wellbore path.
4 . The method of claim 1 , wherein a selected percentage of sub-regions in the plurality of sub-regions are divided into the first subset.
5 . The method of claim 1 , wherein the local traveltime operator of each sub-region of the first subset is calculated using a 5D brute force method.
6 . The method of claim 1 , further comprising selecting a move-out function parameterized by one or more parameters.
7 . The method of claim 6 , wherein the local traveltime operator of each sub-region in the plurality of sub-regions comprises an independent move-out function of the same mathematical form as the selected move-out function.
8 . The method of claim 6 , further comprising generating a parameter data set for each parameter of the one or more parameters, wherein each parameter data set comprises a value for the associated parameter for each sub-region in the plurality of sub-regions.
9 . The method of claim 8 , wherein when determining the local traveltime operator for each sub-region of the second subset, the convergent POCS method is applied to each parameter dataset.
10 . A non-transitory computer-readable memory comprising computer-executable instructions stored thereon that, when executed on a processor, cause the processor to perform steps comprising:
obtaining a seismic data set from a seismic survey conducted over a subterranean region of interest;
discretizing the seismic data set into a plurality of sub-regions each with a local traveltime operator;
dividing the plurality of sub-regions into a first subset and a second subset;
calculating the local traveltime operator for each sub-region of the first subset;
determining the local traveltime operator for each sub-region of the second subset using a convergent POCS method based, at least in part, on the local traveltime operators for the sub-regions of the first subset;
determining an enhanced seismic dataset by performing non-linear beamforming using the local traveltime operator for each sub-region of the plurality of sub-regions; and
determining a location of a hydrocarbon reservoir in the subterranean region of interest using the enhanced seismic data set.
11 . The non-transitory computer-readable memory of claim 10 , wherein a selected percentage of sub-regions in the plurality of sub-regions are divided into the first subset.
12 . The non-transitory computer-readable memory of claim 10 , wherein the local traveltime operator of each sub-region of the first subset is calculated using a 5D brute force method.
13 . The non-transitory computer-readable memory of claim 11 , wherein the steps further comprise:
receiving a selected move-out function, wherein the selected move-out function is parameterized by one or more parameters.
14 . The non-transitory computer-readable memory of claim 13 , wherein the local traveltime operator of each sub-region in the plurality of sub-regions comprises an independent move-out function of the same mathematical form as the selected move-out function.
15 . The non-transitory computer-readable memory of claim 13 , wherein the steps further comprise:
generating a parameter data set for each parameter of the one or more parameters, wherein each parameter data set comprises a value for the associated parameter for each sub-region in the plurality of sub-regions.
16 . The non-transitory computer-readable memory of claim 15 , wherein when determining the local traveltime operator for each sub-region of the second subset, the convergent POCS method is applied to each parameter dataset.
17 . The non-transitory computer-readable memory of claim 11 , wherein the convergent POCS method comprises a convergence criterion.
18 . A system, comprising:
a seismic acquisition system configured to perform a seismic survey over a subterranean region of interest and record a seismic data set; and
a computer processor configured to:
obtain the seismic data set from the seismic acquisition system;
discretize the seismic data set into a plurality of sub-regions each with a local traveltime operator;
divide the plurality of sub-regions into a first subset and a second subset;
calculate the local traveltime operator for each sub-region of the first subset;
determine the local traveltime operator for each sub-region of the second subset using a convergent POCS method based, at least in part, on the local traveltime operators for the sub-regions of the first subset;
determine an enhanced seismic dataset by performing non-linear beamforming using the local traveltime operator for each sub-region of the plurality of sub-regions; and
determine a location of a hydrocarbon reservoir in the subterranean region of interest using the enhanced seismic data set.
19 . The system of claim 18 , further comprising a wellbore planning system configured to plan a wellbore to penetrate the hydrocarbon reservoir based on the location, wherein the planned wellbore comprises a planned wellbore path.
20 . The system of claim 19 , further comprising a wellbore drilling system configured to drill a wellbore guided by the planned wellbore path.