Velocity model building for seismic data processing using PP-PS tomography with co-depthing constraint
AssigneeCgg Services SAS
InventorsPatrice Guillaume, Francesco Perrone
Life of this patent
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Abstract
Methods and systems for processing seismic data are presented. Primary wave (P) seismic data (PP data) and shear wave (P) seismic data (PS data) are jointly inverted as part of a nonlinear tomography process which adheres to one or more co-depthing constraints.
Claims16
A method for seismic exploration processing seismic data acquired with multicomponent receivers over a subsurface, the method jointly inverting depth migrated primary wave (P) seismic reflection data (PP data) and depth migrated shear wave (S) seismic reflection data (PS data) by:
- picking P and S horizons, P and S residual moveouts (RMOs) and P and S dips for the depth-migrated PP and PS data;
- performing a kinematic de-migration of the picked P and S horizons, P and S RMOs and P and S dips to calculate P and S horizon invariants and PP and PS RMO invariants;
- performing a kinematically forward modelling inversion of:
- the PP and PS data using the PP and PS RMO invariants and the P and S horizon invariants to predict PP and PS RMO values, and
- PP-PS co-depthing data based on one or more image co-depthing constraints to calculate co-depthing mismatches;
- calculating a cost function based on the predicted PP and PS RMO values and the co-depthing mismatches;
- updating the P- and S-velocity models simultaneously to minimize the cost function;
- and
- detecting presence of oil and/or gas in the subsurface using an image generated based on the updated P- and S-velocity models.
A computer system for seismic exploration processing seismic data, the computer system comprising:
- an interface configured to receive seismic data acquired with multicomponent receivers over a subsurface;
- and
- at least one processor configured to jointly invert depth migrated primary wave (P) seismic reflection data (PP data) included in the seismic data and depth migrated shear wave (S) seismic reflection data (PS data) included in the seismic data by:
- picking P and S horizons, P and S residual moveouts (RMOs) and P and S dips for the depth-migrated PP and PS data;
- performing a kinematic de-migration of the picked P and S horizons, P and S RMOs and P and S dips to calculate P and S horizon invariants and PP and PS RMO invariants;
- performing a kinematically forward modelling inversion of:
- the seismic data using the P and S horizon invariants to predict PP and PS RMO values, and
- PP-PS co-depthing data based on one or more image co-depthing constraints to calculate co-depthing mismatches;
- calculating a cost function based on the predicted PP and PS RMO values and the co depthing mismatches;
- updating the P- and S-velocity models simultaneously to minimize the cost function;
- and
- detecting presence of oil and/or gas in the subsurface using an image generated based on the updated P- and S-velocity models.
Dependencies are inferred from the claim text.