NOISE SUPPRESSION FOR DETECTION AND LOCATION OF MICROSEISMIC EVENTS USING A MATCHED FILTER
A method for determining presence of seismic events in seismic signals includes determining presence of at least one seismic event in seismic signals corresponding to each of a plurality of seismic sensors. A correlation window is selected for each of the plurality of seismic signals. Each correlation window has a selected time interval including an arrival time of the at least one seismic event in each seismic signal. Each window is correlated to the respective seismic signal between a first selected time and a second selected time. Presence of at least one other seismic event in the seismic signals from a result of the correlating.
1 . A method for determining presence of seismic events in seismic signals, comprising:
determining presence of at least one seismic event in seismic signals corresponding to each of a plurality of seismic sensors;
selecting a correlation window from each of the plurality of seismic signals, each correlation window having a selected time interval including an arrival time of the at least one seismic event in each seismic signal;
correlating each window to the respective seismic signal between a first selected time and a second selected time; and
determining presence of at least one other seismic event in the seismic signals from a result of the correlating.
2 . The method of claim 1 wherein the determining presence of the at least one seismic event comprises selecting signal amplitude above a selected threshold in each of the seismic signals and determining whether arrival time of events above the selected threshold correspond to normal moveout of seismic energy.
3 . The method of claim 1 further comprising determining a spatial origin of the at least one seismic event and the at least one other seismic event.
4 . The method of claim 1 further comprising determining a time of origin of the at least one seismic event and the at least one other seismic event.
5 . The method of claim 1 wherein the at least one seismic event and the at least one other seismic event are spatially related.
6 . The method of claim 1 wherein the at least one seismic event and the at least one other seismic event are related in mechanism of origin.
7 . The method of claim 1 wherein the seismic signals are acquired from an array of seismic sensors deployed near the Earth's surface.
8 . The method of claim 1 wherein the at least one seismic event and the at least one other seismic event are generated by pumping fluid into a subsurface formation.
9 . A method for seismic evaluation of the Earth's subsurface, comprising:
deploying a plurality of seismic sensors proximate a volume of the Earth's subsurface to be evaluated;
detecting seismic signals from each of the sensors for a selected time interval;
determining presence of at least one seismic event in the seismic signals corresponding to each of the seismic sensors;
selecting a correlation window from each of the seismic signals, each correlation window having a selected time interval including an arrival time of the at least one seismic event in each seismic signal;
correlating each window to the respective seismic signal between a first selected time and a second selected time; and
determining presence of at least one other seismic event in the seismic signals from a result of the correlating.
10 . The method of claim 9 wherein the determining presence of the at least one seismic event comprises selecting signal amplitude above a selected threshold in each of the seismic signals and determining whether arrival time of events above the selected threshold correspond to normal moveout of seismic energy.
11 . The method of claim 9 further comprising determining a spatial origin of the at least one seismic event and the at least one other seismic event.
12 . The method of claim 9 further comprising determining a time of origin of the at least one seismic event and the at least one other seismic event.
13 . The method of claim 9 wherein the at least one seismic event and the at least one other seismic event are spatially related.
14 . The method of claim 9 wherein the at least one seismic event and the at least one other seismic event are related in mechanism of origin.
15 . The method of claim 9 wherein the seismic signals are acquired from an array of seismic sensor deployed near the Earth's surface.
16 . The method of claim 9 wherein the at least one seismic event and the at least one other seismic event are generated by pumping fluid into a subsurface formation.
17 . The method of claim 9 where at least one event is perforation shot.
18 . The method of claim 9 wherein the at least one seismic event and the at least one other seismic event are generated by reservoir subsidence
19 . The method of claim 9 wherein the at least one seismic event and the at least one other seismic event are generated by casing failure in a subsurface formation.