System, method and computer program product for stacking seismic noise data to analyze seismic events

1. A method for determining a seismic event from indications of seismic noise, the method comprising:

receiving seismic trace data responsive to the seismic noise generated within a formation at sensors at a plurality of locations; and

using a processor to:

determine a virtual trace from the seismic trace data for a virtual trace location related to the plurality of locations, and

determine a virtual trace value (E Rvirtual ) for the determined virtual trace from normalized values of the seismic trace data and a normalized value of the determined virtual trace, wherein the virtual trace value indicates a presence of the seismic event.

2. The method of claim 1 , further comprising determining the virtual trace location by calculating at least one of a geometric center and a center of gravity of a shape formed by the plurality of locations.

3. The method of claim 1 , further comprising using the processor to normalize the seismic trace data.

4. The method of claim 1 , further comprising:

receiving at least one trace (trace m (t)) from each of the plurality of locations; and

calculating a sum of the at least one trace (trace m (t)) for each of the plurality of locations.

5. The method of claim 1 , further comprising:

receiving at least one trace (trace m (t)) from the sensors at each of the plurality of locations within a time window; and

calculating a resultant trace (E Rn (t)) using the equation:

E Rn ( t )=sqrt[trace 1 ( t ) 2 + . . . trace m ( t ) 2 ],

“trace m (t)” representing one or more traces received from each of the plurality of locations within the time window.

6. The method of claim 1 , further comprising:

receiving seismic trace data from sensors at another plurality of locations;

providing another virtual trace value as seismic event data for another virtual trace location; and

comparing the virtual trace value (E Rvirtual ) and the another virtual trace value to a threshold value to determine a location of the seismic event.

7. The method of claim 1 , further comprising:

calculating the virtual trace value (E Rvirtual ) using the equation:

E Rvirtual ( t )=[ E R1 ( t )+ . . . E Rn ( t )]

wherein “E R1 (t) . . . E Rn (t)” represents the seismic trace data for each of the plurality of locations.

8. The method of claim 7 , further comprising:

calculating the virtual trace value (E Rvirtual ) using the equation:

E Rvirtual =(1 /N )*∫ E Rvirtual ( t ) dt/[∫E R1 ( t ) dt+ . . . ∫E Rn ( t ) dt],

wherein “N” represents a number of locations in the plurality of locations.

9. The method of claim 8 , further comprising determining a threshold value indicative of a seismic event.

10. The method of claim 1 , further comprising using the processor to:

compare a threshold value to the virtual trace value (E Rvirtual ) to determine whether the seismic event has occurred.