Non-hyperbolic correction of seismic data

Abstract

A method for improving seismic images by correction of distortions in the underlying seismic data caused by a near-surface anomaly that produces a non-hyperbolic move-out component of the seismic reflection below the anomaly includes the steps of: a. redatuming the input seismic data to go from the surface to a target horizon using true one-way traveltime operators to provide a first new redatuming dataset; b. redatuming the input seismic data using hyperbolic one-way travel time operators to provide a second new redatuming dataset; and c. redatuming the combination of a first causal part of the first new redatuming dataset and an anti-causal second part of the second redatuming dataset to go from the target horizon back to the surface using hyperbolic one-way traveltime operators to provide a dataset that is referenced to the surface without an imprint of the anomaly.

1 . A method for improving seismic images by correction of distortions in the underlying input seismic data caused by a near-surface anomaly that produces a non-hyperbolic move-out component of the seismic reflection below the anomaly, the method comprising:
 a. redatuming the input seismic data to go from the surface to a target horizon using true one-way traveltime operators to provide a first new redatuming dataset;   b. redatuming the input seismic data using hyperbolic one-way traveltime operators to provide a second new redatuming dataset; and   c. redatuming the combination of a first causal part of the first new redatuming dataset and an anti-causal second part of the second redatuming dataset to go from the target horizon back to the surface using hyperbolic one-way traveltime operators,   
       to thereby provide a dataset that is referenced to the surface without an imprint of the anomaly. 
     
     
         2 . The method of  claim 1  in which the true one-way traveltime operators are derived from the true two-way traveltime of the target horizon, and the hyperbolic one-way traveltime operators are derived from the hyperbolic component of the target horizon. 
     
     
         3 . The method of  claim 2  in which the horizon is selected in the prestack data domain or by stacking velocity analysis followed by trim statics analysis around the target horizon. 
     
     
         4 . The method of  claim 1  in which the two sets of true and hyperbolic two-way traveltimes are converted, respectively, to one-way traveltime operators utilizing an inversion algorithm. 
     
     
         5 . The method of  claim 4  in which the inversion algorithm is a generic algorithm.