Correcting geometry-related time and amplitude errors

Abstract

A method for predicting a plurality of surface multiples for a plurality of target traces in a record of seismic data acquired in a survey area. The method includes selecting a target trace and identifying two or more desired traces for multiple prediction based on the target trace. After identifying the desired traces, the method identifies one or more recorded traces for each desired trace. Each identified recorded trace is described as being substantially close to one of the desired traces. The method then includes correcting the identified recorded traces for one or more geometry-related effects associated with the survey area and convolving the corrected recorded traces to generate a plurality of convolutions. After convolving the corrected recorded traces, the method then stacks the convolutions.

What is claimed is: 
     
         1 . A method for predicting a plurality of surface multiples for a plurality of target traces in a record of seismic data acquired in a survey area, comprising:
 selecting a target trace;   identifying two or more desired traces for multiple prediction based on the target trace;   identifying one or more recorded traces that are substantially close to the location of one of the desired traces;   correcting the identified recorded traces for one or more geometry-related effects associated with the survey area using one or more geometry-related effects associated with the desired traces;   convolving the corrected recorded traces to generate one or more convolutions; and   stacking the convolutions to obtain a stacked convolution for the target trace.   
     
     
         2 . The method of  claim 1 , wherein the geometry-related effects comprise one or more amplitude variations. 
     
     
         3 . The method of  claim 1 , wherein the desired traces correspond to one or more potential downward reflection points, and wherein correcting the identified recorded traces comprises:
 determining one or more near surface amplitude anomalies located at the potential downward reflection points; and   scaling the identified recorded traces by the near surface amplitude anomalies located at the potential downward reflection points.   
     
     
         4 . The method of  claim 1 , wherein correcting the identified recorded traces comprises:
 identifying a potential downward reflection point associated with the target trace;   determining one or more near surface amplitude anomalies located at a source location and a receiver location associated with each of the identified recorded traces;   determining one or more near surface amplitude anomalies located at one or more source locations, one or more receiver locations and the potential downward reflection point;   determining one or more differential near surface amplitude anomalies between the near surface amplitude anomalies located at the source location and the receiver location associated with each of the identified recorded traces and the near surface amplitude anomalies located at the source locations, the receiver locations and the potential downward reflection point; and   applying the differential near surface amplitude anomalies to the identified recorded traces.   
     
     
         5 . The method of  claim 1 , wherein the geometry-related effects comprise one or more effects due to one or more structural dips. 
     
     
         6 . The method of  claim 5 , wherein the effects due to the structural dips are corrected by:
 estimating one or more timing differences between the identified recorded traces and the desired traces based on a model of a horizon of the survey area; and   applying one or more time shifts to the identified recorded traces based on the estimated timing differences.   
     
     
         7 . The method of  claim 1 , wherein the geometry-related effects comprise one or more effects due to anisotropy. 
     
     
         8 . The method of  claim 7 , wherein the effects due to anisotropy are corrected by:
 receiving one or more velocity fields for the identified recorded traces;   estimating one or more differential travel times between the identified recorded traces and one or more corresponding desired traces based on the velocity fields; and   applying one or more time shifts to the identified recorded traces based on the estimated differential travel times.   
     
     
         9 . A method for predicting a plurality of surface multiples for a plurality of target traces in a record of seismic data acquired in a survey area, comprising:
 selecting a target trace;   identifying a potential downward reflection point for multiple prediction based on the target trace;   identifying two or more recorded traces that correspond to the potential downward reflection point;   correcting the identified recorded traces for one or more geometry-related effects associated with the potential downward reflection point;   convolving the corrected recorded traces to generate one or more convolutions; and   stacking the convolutions to obtain a stacked convolution for the target trace.   
     
     
         10 . The method of  claim 9 , wherein correcting the identified recorded traces comprises:
 determining one or more statics located at the potential downward reflection point; and   adding the statics located at the potential downward reflection point to the identified recorded traces.   
     
     
         11 . The method of  claim 9 , wherein correcting the identified recorded traces comprises:
 determining one or more statics located at a source location and a receiver location associated with each of the identified recorded traces;   determining one or more statics located at one or more source locations, one or more receiver locations and the potential downward reflection point;   determining one or more differential statics between the statics located at the source location and the receiver location associated with each of the identified recorded traces and the statics located at the source locations, the receiver locations and the potential downward reflection point; and   applying the differential statics to the identified recorded traces.   
     
     
         12 . The method of  claim 11 , wherein the differential statics is a difference between the statics located at the source location and the receiver location associated with each of the identified recorded traces and the statics located at the source locations, the receiver locations and the potential downward reflection point. 
     
     
         13 . The method of  claim 9 , wherein correcting the identified recorded traces comprises:
 determining one or more near surface amplitude anomalies located at the potential downward reflection point; and   scaling the identified recorded traces by the near surface amplitude anomalies located at the potential downward reflection point.   
     
     
         14 . The method of  claim 9 , wherein correcting the identified recorded traces comprises:
 determining one or more near surface amplitude anomalies located at a source location and a receiver location associated with each of the identified recorded traces;   determining one or more near surface amplitude anomalies located at one or more source locations, one or more receiver locations and the potential downward reflection point;   determining one or more differential near surface amplitude anomalies between the near surface amplitude anomalies located at the source location and the receiver location associated with each of the identified recorded traces and the near surface amplitude anomalies located at the source locations, the receiver locations and the potential downward reflection point; and   applying the differential near surface amplitude anomalies to the identified recorded traces.   
     
     
         15 . The method of  claim 1 , wherein the geometry-related effects comprise one or more amplitude variations, one or more effects due to one or more structural dips, one or more effects due to anisotropy, or a combination thereof. 
     
     
         16 . A system, comprising:
 a processor; and   a memory comprising program instructions executable by the processor to:
 select a target trace; 
 identify two or more desired traces for multiple prediction based on the target trace; 
 identify one or more recorded traces that are substantially close to the location of one of the desired traces; 
 correct the identified recorded traces for one or more geometry-related effects associated with the survey area using one or more geometry-related effects associated with the desired traces; 
 convolve the corrected recorded traces to generate one or more convolutions; and 
 stack the convolutions to obtain a stacked convolution for the target trace. 
   
     
     
         17 . The system of  claim 16 , wherein the memory further comprises program instructions executable by the processor to:
 determine one or more statics associated with the locations of the desired traces; and   add the statics to the identified recorded traces.   
     
     
         18 . The system of  claim 16 , wherein the memory further comprises program instructions executable by the processor to:
 identify a potential downward reflection point associated with the target trace;   determine the one or more statics located at a source location and a receiver location associated with each of the identified recorded traces;   determine one or more statics located at one or more source locations, one or more receiver locations and the potential downward reflection point;   determine one or more differential statics between the statics located at the source location and the receiver location associated with each of the identified recorded traces and the statics located at the source locations, the receiver locations and the potential downward reflection point; and   apply the differential statics to the identified recorded traces.   
     
     
         19 . The system of  claim 16 , wherein the desired traces correspond to one or more potential downward reflection points, and wherein the program instructions executable by the processor to correct the identified recorded traces comprises program instructions executable by the processor to:
 determine one or more near surface amplitude anomalies located at the potential downward reflection points; and   scale the identified recorded traces by the near surface amplitude anomalies located at the potential downward reflection points.   
     
     
         20 . The system of  claim 16 , wherein the geometry-related effects comprise one or more amplitude variations, one or more effects due to one or more structural dips, one or more effects due to anisotropy, or a combination thereof.