Measuring discontinuity in seismic data

Abstract

Various methods for measuring continuity and discontinuity of a seismic data set. One method embodiment includes: a) detecting seismic energy with an array of detectors; b) converting detection signals from the array of detectors into data representing one or more attributes as a function of position for subsurface formations; c) systematically obtaining subsets of the data as vector sets; and d) for each vector set: (1) combining vectors from the vector set to determine a representative vector for the vector set; and (2) calculating a continuity or discontinuity measurement with respect to the representative vector. In various embodiments, the continuity or discontinuity measurement may be expressible as a fraction of vector set energy derived from vector components aligned with or deviating from the representative vector.

1 . A method of measuring continuity of a data set, the method comprising: 
 obtaining a vector set from the data set;    combining vectors from the vector set to determine a representative vector for the vector set; and    calculating a continuity measurement for the vector set.    
   
   
       2 . The method of  claim 1 , wherein said calculating a continuity measurement includes: 
 finding for each vector in the vector set a projection value indicative of a projection of the vector along a line of similarity defined by the representative vector.    
   
   
       3 . The method of  claim 2 , wherein said calculating a continuity measurement further includes: 
 summing squares of the projection values to obtain a sum of projection squares.    
   
   
       4 . The method of  claim 3 , wherein said calculating a continuity measurement further includes: 
 normalizing the sum of projection squares to obtain the continuity measurement for the vector set.    
   
   
       5 . (canceled)  
   
   
       6 . The method of  claim 2 , wherein said calculating a continuity measurement further includes: 
 normalizing a square of the projection value for each vector in the vector set; and    averaging the normalized squares of projection values to obtain the continuity measurement for the vector set.    
   
   
       7 . (canceled)  
   
   
       8 . The method of  claim 1 , wherein said combining vectors from the vector set to determine a representative vector for the vector set includes: 
 summing the vectors in the vector set.    
   
   
       9 . The method of  claim 8 , wherein said combining vectors from the vector set to determine a representative vector from the vector set further includes: 
 dividing a sum of the vectors in the vector set to obtain an average vector.    
   
   
       10 . The method of  claim 1 , wherein said combining vectors from the vector set to determine a representative vector for the vector set includes: 
 determining a weighted sum of the vectors in the vector set.    
   
   
       11 . The method of  claim 1 , wherein said combining vectors from the vector set to determine a representative vector for the vector set includes: 
 determining the representative vector to be that vector that minimizes a total distance measurement between the representative vector and each of the vectors in the set.    
   
   
       12 .- 14 . (canceled)  
   
   
       15 . The method of  claim 1 , further comprising: 
 repeating said obtaining, combining, and calculating to obtain a set of continuity measurements each having an associated spatial position.    
   
   
       16 . The method of  claim 1 , further comprising: 
 displaying the set of continuity measurements as a function of spatial position.    
   
   
       17 . The method of  claim 1 , wherein the data set is derived from a seismic survey.  
   
   
       18 . A method of measuring continuity of a data set, the method comprising: 
 obtaining a vector set from the data set;    determining a representative vector for the vector set; and    calculating a continuity measurement for the vector set, wherein said calculating includes:    finding for each vector in the vector set a projection value indicative of a projection of the vector along a line defined by the representative vector.    
   
   
       19 . The method of  claim 18 , wherein said calculating a continuity measurement further includes: 
 summing squares of the projection values to obtain a sum of projection squares.    
   
   
       20 . The method of  claim 19 , wherein said calculating a continuity measurement further includes: 
 normalizing the sum of projection squares to obtain the continuity measurement for the vector set.    
   
   
       21 . The method of  claim 18 , wherein said calculating a continuity measurement further includes: 
 normalizing a square of the projection value for each vector in the vector set; and averaging the normalized squares of projection values to obtain the continuity measurement for the vector set.    
   
   
       22 . The method of  claim 18 , wherein the data set is derived from a seismic survey.  
   
   
       23 . A method of measuring discontinuity of a data set, the method comprising: 
 obtaining a vector set from the data set;    combining vectors from the vector set to determine a representative vector for the vector set; and    calculating a discontinuity measurement for the vector set.    
   
   
       24 . The method of  claim 23 , wherein said calculating a discontinuity measurement includes: 
 finding for each vector in the vector set a projection value indicative of a projection of the vector perpendicular to a line defined by the representative vector.    
   
   
       25 . The method of  claim 24 , wherein said calculating a discontinuity measurement includes: 
 summing squares of projection values determined relative to the representative vector to obtain a sum of projection squares.    
   
   
       26 . The method of  claim 23 , wherein said calculating a discontinuity measurement includes: 
 normalizing a square of a projection value for each vector in the vector set; and    averaging the normalized squares of projection values to obtain the discontinuity measurement for the vector set.    
   
   
       27 . (canceled)  
   
   
       28 . The method of  claim 24 , wherein said calculating a discontinuity measurement further includes: 
 normalizing a square of the projection value for each vector in the vector set; and    averaging the normalized squares of projection values to obtain the discontinuity measurement for the vector set.    
   
   
       29 . (canceled)  
   
   
       30 . The method of  claim 23 , wherein said combining vectors from the vector set to determine a representative vector for the vector set includes: 
 summing the vectors in the vector set.    
   
   
       31 . The method of  claim 30 , wherein said combining vectors from the vector set to determine a representative vector from the vector set further includes: 
 dividing a sum of the vectors in the vector set to obtain an average vector.    
   
   
       32 . The method of  claim 23 , wherein said combining vectors from the vector set to determine a representative vector for the vector set includes: 
 determining a weighted sum of the vectors in the vector set.    
   
   
       33 . The method of  claim 23 , wherein said combining vectors from the vector set to determine a representative vector for the vector set includes: 
 determining the representative vector to be that vector that minimizes a total distance measurement between the representative vector and each of the vectors in the set.    
   
   
       34 .- 36 . (canceled)  
   
   
       37 . The method of  claim 23 , further comprising: 
 repeating said obtaining, combining, and calculating to obtain a set of continuity measurements each having an associated spatial position.    
   
   
       38 . The method of  claim 23 , further comprising: 
 displaying the set of continuity measurements as a function of spatial position.    
   
   
       39 . The method of  claim 38 , wherein the data set is derived from a seismic survey.  
   
   
       40 . A method of measuring discontinuity of a data set, the method comprising: 
 obtaining a vector set from the data set;    determining a representative vector for the vector set; and    calculating a discontinuity measurement for the vector set, wherein said calculating includes: 
 finding for each vector in the vector set a projection value indicative of a projection of the vector perpendicular to a line defined by the representative vector.  
   
   
   
       41 . The method of  claim 40 , wherein said calculating a discontinuity measurement further includes: 
 summing squares of the projection values to obtain a sum of projection squares.    
   
   
       42 . The method of  claim 41 , wherein said calculating a discontinuity measurement further includes: 
 normalizing the sum of projection squares to obtain the discontinuity measurement for the vector set.    
   
   
       43 . The method of  claim 40 , wherein said calculating a discontinuity measurement further includes: 
 normalizing a square of the projection value for each vector in the vector set; and    averaging the normalized squares of projection values to obtain the discontinuity measurement for the vector set.    
   
   
       44 . The method of  claim 40 , wherein the data set is derived from a seismic survey.  
   
   
       45 . A method of seismic exploration that comprises: 
 detecting seismic energy with an array of detectors;    converting detection signals from the array of detectors into data representing one or more attributes as a function of position for subsurface formations;    systematically obtaining subsets of the data as vector sets; and    for each vector set: 
 combining vectors from the vector set to determine a representative vector for the vector set; and  
 calculating a continuity or discontinuity measurement with respect to the representative vector.  
   
   
   
       46 . The method of  claim 45 , further comprising: 
 displaying the continuity or discontinuity measurement as a function of position.    
   
   
       47 . The method of  claim 46 , wherein said displaying includes: 
 providing a two-dimensional map with the continuity or discontinuity measurement indicated by color or intensity.    
   
   
       48 . The method of  claim 46 , wherein said displaying includes: 
 providing a view in which the continuity or discontinuity measurements are shown as a function of three spatial dimensions.    
   
   
       49 . The method of  claim 45 , wherein said combining vectors from the vector set to determine a representative vector for the vector set includes: 
 summing the vectors in the vector set.    
   
   
       50 . The method of  claim 49 , wherein said combining vectors from the vector set to determine a representative vector from the vector set further includes: 
 dividing a sum of the vectors in the vector set to obtain an average vector.    
   
   
       51 . The method of  claim 45 , wherein said combining vectors from the vector set to determine a representative vector for the vector set includes: 
 determining a weighted sum of the vectors in the vector set.    
   
   
       52 . The method of  claim 45 , wherein said combining vectors from the vector set to determine a representative vector for the vector set includes: 
 determining the representative vector to be that vector that minimizes a total distance measurement between the representative vector and each of the vectors in the set.    
   
   
       53 .- 55 . (canceled)  
   
   
       56 . A seismic survey system comprising: 
 a data storage device that stores seismic measurements;    a processor that retrieves said seismic measurements as one or more vector sets and combines vectors from at least one of the vector sets to determine a representative vector, wherein said processor calculates a continuity or discontinuity measurement with respect to the representative vector.    
   
   
       57 . The system of  claim 56 , wherein the processor combines vectors to determine a representative vector by summing the vectors in said at least one of the vector sets.  
   
   
       58 . The system of  claim 57 , wherein the processor determines the representative vector by further dividing a sum of the vectors in said at least one of the vector sets to obtain an average vector.  
   
   
       59 . The system of  claim 56 , wherein the processor combines vectors to determine the representative vector by determining a weighted sum of the vectors in said at least one of the vector sets.  
   
   
       60 . The system of  claim 56 , wherein the processor combines vectors to determine the representative vector by deterring the representative vector to be that vector that minimizes a total distance measurement between the representative vector and each of the vectors in said at least one of the vector sets.  
   
   
       61 . The system of  claim 60 , wherein the total distance measurement combines Manhattan distance measurements from the representative vector to each of the vectors in said at least one of the vector sets.  
   
   
       62 .- 63 . (canceled)  
   
   
       64 . The system of  claim 56  further comprising a display for the continuity or discontinuity measurements.  
   
   
       65 . A method of seismic exploration that comprises: 
 detecting seismic energy with an array of detectors;    converting detection signals from the array of detectors into data representing one or more attributes as a function of position for subsurface formations;    systematically obtaining subsets of the data as vector sets; and    for each vector set: 
 averaging vectors from the vector set to determine a representative vector for the vector set;  
 calculating a continuity or discontinuity measurement with respect to the representative vector; and  
 providing a display with the continuity or discontinuity measurement indicated by color intensity.