Method for wavefield-based data processing including utilizing multiples to determine subsurface characteristics of a suburface region
AssigneeChevron U.S.A. Inc.
InventorWei Liu
Life of this patent
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Abstract
Despite full waveform propagation capabilities offered by reverse time migration or inversion, prior art methods can generate spurious events from multiples and therefore are limited to using data without free-surface multiples. By eliminating or largely reducing artificial transmission of multiples, the enhanced reverse time migration or inversion in the present invention can correctly use data that contain free-surface and internal multiples and improve image quality or properties estimation.
Claims8
A method for wavefield-based seismic data processing including utilizing multiples to obtain characteristics of a subsurface region of interest, the method includes:
- obtaining an earth model and a migration model related to the subsurface region of interest;
- determining a modeling geometry related to the subsurface region of interest for the earth model and for the migration model;
- propagating forward at least one wavefield in the earth model from at least one excitation source obtained from the modeling geometry;
- propagating forward at least one wavefield in the migration model from the at least one excitation source obtained from the modeling geometry;
- propagating backward at least one wavefield in the earth model utilizing at least one receiver location obtained from the modeling geometry;
- determining at least one composite wavefield from the forward and the backward propagated wavefields from the earth model, and applying imaging conditions to the forward propagated wavefield from the migration model and the composite wavefield from the earth model, wherein the imaging conditions utilize the multiples present in the composite wavefield to determine characteristics of the subsurface region of interest without generating corresponding spurious events of the multiples.
A system configured to perform wavefield-based seismic data processing including utilizing multiples to obtain characteristics of a subsurface region of interest, the system comprising:
- a data storage device having computer readable data including an earth model and a migration model related to the subsurface region of interest;
- a processor, configured and arranged to execute machine executable instructions stored in a processor accessible memory for performing a method comprising:
- determining a modeling geometry related to the subsurface region of interest for the earth model and for the migration model;
- propagating forward at least one wavefield in the earth model from at least one excitation source obtained from the modeling geometry;
- propagating forward at least one wavefield in the migration model from the at least one excitation source obtained from the modeling geometry;
- propagating backward at least one wavefield in the earth model utilizing at least one receiver location obtained from the modeling geometry;
- determining at least one composite wavefield from the forward and the backward propagated wavefields from the earth model, and applying imaging conditions to the forward propagated wavefield accessed in reverse time order from the migration model and the composite wavefield from the earth model, wherein the imaging conditions utilize the multiples present in the composite wavefield to determine characteristics of the subsurface region of interest without generating corresponding spurious events of the multiples.
Dependencies are inferred from the claim text.