Seismic data acquisition using designed non-uniform receiver spacing

Abstract

The presently disclosed technology relates to an arrangement for seismic acquisition where the spacing between adjacent pairs of receiver and sources lines is not all the same. Some receiver and/or source lines and/or receiver and/or source spacings are larger and some are smaller to provide a higher quality wavefield reconstruction when covering a larger total area or for a similar total area of seismic data acquisition, while providing a wavefield that is optimally sampled by the receivers and sources so that the wavefield reconstruction is suitable for subsurface imaging needs.

1 . A method of characterizing a geological subsurface, the method comprising:
 obtaining seismic data based on seismic energy detected by a plurality of seismic receivers in a deliberately non-uniform arrangement, the seismic energy generated at a plurality of seismic source points within the survey area, the plurality of seismic receivers deployed at a plurality of positions within a survey area according to a seismic survey, the survey area including the geological subsurface, the plurality of positions of the seismic survey including a first position for a first seismic receiver, a second position for a second seismic receiver, and a third position for a third seismic receiver, the plurality of positions of the deliberately non-uniform arrangement selected, such that:
 the first position for the first seismic receiver is not aligned along a first direction with the second position for the second seismic receiver, and 
 the first position for the first seismic receiver is not aligned along a second direction with the third position for the third seismic receiver; 
   generating a reconstructed wavefield representing the geological subsurface, the reconstructed wavefield generated based on the seismic data, one or more drilling locations within the survey area being planned based on the reconstructed wavefield, a natural resource being obtained from the geological subsurface by drilling at the one or more drilling locations.   
     
     
         2 . The method of  claim 1 , wherein the first seismic receiver and the second seismic receiver are within a first receiver line. 
     
     
         3 . The method of  claim 2 , wherein the third seismic receiver is within a second receiver line, the first receiver line being different from the second receiver line. 
     
     
         4 . The method of  claim 1 , wherein the seismic survey includes a non-uniform spacing between receiver lines including the plurality of seismic receivers. 
     
     
         5 . The method of  claim 1 , wherein the second direction is perpendicular to the first direction. 
     
     
         6 . The method of  claim 1 , wherein the plurality of positions for the plurality of receivers has a deliberately non-uniform spacing between pairs of adjacent receivers in at least one of the first direction or the second direction. 
     
     
         7 . The method of  claim 6 , wherein the deliberately non-uniform spacing is two-dimensionally non-uniform. 
     
     
         8 . The method of  claim 1 , wherein a smallest spacing distance between adjacent seismic receivers of the plurality of seismic receivers is at least five percent less than a largest spacing distance between the adjacent seismic receivers of the plurality of seismic receivers, the smallest spacing distance and the largest spacing distance both measured along one of the first direction or the second direction. 
     
     
         9 . The method of  claim 1 , wherein each of the plurality of positions is not randomly selected. 
     
     
         10 . The method of  claim 1 , wherein the reconstructed wavefield is generated using a statistical linear regression analysis. 
     
     
         11 . The method of  claim 1 , wherein the reconstructed wavefield is iteratively refined based on measured data from the seismic survey, the seismic survey being a sparse seismic survey. 
     
     
         12 . The method of  claim 1 , wherein the reconstructed wavefield is created using a statistical linear regression analysis that minimizes L0 and L1 norms, such that the reconstructed wavefield represents an actual wavefield of the geological subsurface. 
     
     
         13 . A system for characterizing a geological subsurface, the system comprising:
 a plurality of seismic receivers configured to detect seismic energy within a survey area, the plurality of seismic receivers deployed at a plurality of positions within the survey area in a deliberately non-uniform arrangement according to a seismic survey designed to characterize the geological subsurface;   a first seismic receiver of the plurality of seismic receivers deployed at a first position of the plurality of positions;   a second seismic receiver of the plurality of seismic receivers deployed at a second position of the plurality of positions; and   a third seismic receiver of the plurality of seismic receivers deployed at a third position of the plurality of positions, the plurality of positions of the deliberately non-uniform arrangement selected, such that:
 the first position for the first seismic receiver is not aligned along a first direction with the second position for the second seismic receiver, and 
 the first position for the first seismic receiver is not aligned along a second direction with the third position for the third seismic receiver. 
   
     
     
         14 . The system of  claim 13 , wherein the seismic energy is generated at one or more seismic source points within the survey area. 
     
     
         15 . The system of  claim 14 , wherein the seismic energy is generated by one or more vibrator trucks positioned at the one or more seismic source points. 
     
     
         16 . The system of  claim 14 , wherein the one or more of seismic source points is uniformly arranged within the survey area. 
     
     
         17 . The system of  claim 13 , wherein each of the plurality of positions is not randomly selected. 
     
     
         18 . The system of  claim 13 , wherein the plurality of positions are selected based on one or more synthetic seismic surveys generated using a computer, each of the one or more synthetic seismic surveys using a different arrangement of the plurality of seismic receivers. 
     
     
         19 . The system of  claim 13 , wherein the second direction is perpendicular to the first direction. 
     
     
         20 . The system of  claim 13 , wherein the plurality of positions for the plurality of receivers has a deliberately non-uniform spacing between pairs of adjacent receivers in at least one of the first direction or the second direction.