Plural-depth buried seismic sensors acquisition system and method

Abstract

A system for collecting seismic data includes plural seismic sensors. The seismic sensors are buried underground. In one application, a first set of seismic sensors are buried at a first depth and a second set of seismic sensors are buried at a second depth. In another application, the sensors alternate along a line, one sensor from the first set and a next sensor from a second set. In still another application, the sensors are randomly distributed below the ground.

1 - 8 . (canceled) 
     
     
         9 . A seismic data acquisition system for recording seismic waves related to a subsurface to be surveyed, the system comprising:
 first and second sets of seismic sensors distributed underground at first and second depths (d 1 , d 2 ),   wherein each sensor of the first set of seismic sensors is located at the first depth (d 1 ), and each sensor of the second set of seismic sensors is located at the second depth (d 2 ),   the first and second sets of seismic sensors are buried underground beneath a weathering layer, and   the first and second sets of seismic sensors are monitoring the subsurface for determining changes in the subsurface.   
     
     
         10 . The system of  claim 9 , wherein a sensor from the first set of seismic sensors is paired with a sensor from the second set of seismic sensors to be located on a same vertical line relative to a surface of the Earth. 
     
     
         11 . The system of  claim 9 , wherein the first set of seismic sensors mirrors the second set of seismic sensors. 
     
     
         12 . The system of  claim 9 , wherein projections of the first and second sets of seismic sensors on the surface form a line with alternate sensors belonging to each set. 
     
     
         13 . The system of  claim 9 , wherein the first and second sets of seismic sensors form a line of sensors when viewed from above ground. 
     
     
         14 . The system of  claim 13 , further comprising:
 third and fourth sets of sensors that form a second line, the third set being distributed at the first depth and the fourth set being distributed at the second depth.   
     
     
         15 . The system of  claim 9 , wherein the first and second sets of seismic sensors include at least one of a hydrophone, geophone, accelerometer or a combination thereof. 
     
     
         16 . The system of  claim 9 , wherein the subsurface is below the ocean bottom. 
     
     
         17 . The system of  claim 9 , further comprising:
 plural seismic sources buried underground,   wherein the plural seismic sources are located at a same depth.   
     
     
         18 . The system of  claim 17 , wherein the depth of the plural seismic sources is deeper than the first and second depths. 
     
     
         19 . A method for recording seismic waves related to a subsurface to be surveyed, the method comprising:
 burying first and second sets of seismic sensors at first and second depths underground, wherein each sensor of the first set of seismic sensors is located at the first depth (d 1 ), and each sensor of the second set of seismic sensors is located at the second depth (d 2 );   recording with the first and second sets of seismic sensors seismic waves generated by seismic sources; and   processing the recorded seismic waves to remove a ghost and to generate a final image of the subsurface.   
     
     
         20 . The method of  claim 19 , wherein the first and second sets of seismic sensors are buried underground beneath a weathering layer. 
     
     
         21 . The method of  claim 19 , wherein a sensor from the first set of seismic sensors is paired with a sensor from the second set of seismic sensors to be located on a same vertical line relative to a surface of the Earth. 
     
     
         22 . The method of  claim 19 , wherein the first set of seismic sensors mirrors the second set of seismic sensors. 
     
     
         23 . The method of  claim 19 , wherein projections of the first and second sets of seismic sensors on the surface form a line with alternate sensors belonging to each set. 
     
     
         24 . The method of  claim 19 , wherein the first and second sets of seismic sensors form a line of sensors when viewed from above ground. 
     
     
         25 . The method of  claim 24 , further comprising:
 burying third and fourth sets of sensors underground to form a second line, the third set being distributed at the first depth and the fourth set being distributed at the second depth.   
     
     
         26 . The method of  claim 19 , wherein the first and second sets of seismic sensors include at least one of a hydrophone, geophone, accelerometer or a combination thereof. 
     
     
         27 . The method of  claim 19 , wherein the subsurface is below an ocean bottom. 
     
     
         28 . The method of  claim 19 , further comprising:
 burying plural seismic sources underground,   wherein the plural seismic sources are located at a same source depth, which is deeper than the first and second depths.