Patent EA-001766-B1 (EA)
Title: Method of detecting seismic events and for detecting and correcting geometry and statics error in seismic data
Inventor: MARTIN FEDERICO
IPC: G01V1/28
Filed: 1998-07-08
Abstract: 1. A method for automatically detecting substantially linear seismic events in multiple element data, wherein at least one element of the data comprises a shot and at least one other element of the data comprises a receiver, for a common element gather of traces, the method comprising: computing the complex trace envelope of traces of the gather; sorting the gather by a first element line, a first element, a second element line, and a second element, wherein a sorted gather of traces is defined; wherein said computing and said sorting define a sorted gather of complex trace envelopes; transforming the sorted gather of complex trace envelopes into a set of velocity stack trace envelopes; and picking events from the velocity stack trace envelopes. 2. A method for correcting statics errors in a set of seismic data comprising: assembling a set of velocity stack trace envelopes, wherein the velocity stack trace envelopes have a particular shot and receiver location associated with each trace, wherein the velocity stack trace envelopes include representations of multiple event arrivals, wherein some of the event arrivals represent the direct arrival and some represent events other than the direct arrival, wherein the velocity stack trace envelopes include event attributes comprising: time, amplitude, and velocity information for each event; comparing at least one event attribute of at least one of the multiple event arrivals to at least one event attribute of at least one other of the multiple event arrivals; and assigning a statics correction to a source-receiver, dependent upon the comparing. 3. A method for discrimination between statics, geometry, source, and received problems, the method comprising: assembling a set of velocity stack trace envelopes, wherein the velocity stack trace envelopes have a particular shot and receiver location associated with each trace, wherein the velocity stack trace envelopes include representations of multiple event arrivals, wherein some of the event arrivals represent the direct arrival and some represent events other than the direct arrival, wherein the velocity stack trace envelopes include event attributes comprising: time, amplitude, and velocity information for each event; comparing at least one event attribute of at least one of the multiple event arrivals to a threshold value for the at least one event attribute; and discriminating between error type, dependent upon the comparing; assembling a set of velocity stack trace envelopes. 4. A method for correcting geometry errors in a set of seismic data traces, the traces being related to a first element location and a second element location, one of the element locations being a shot location and the other of the elment locations being a receiver location, the method comprising: assembling a set of velocity stack trace envelopes including offset bin information; picking a seismic event from the set of velocity stack trace envelopes; comparing a time delay between the first element location and the second element location to a time delay threshold; and assigning a geometry correction to at least one of the element locations dependent upon the comparing. 5. A method for automatically detecting substantially linear seismic events in multiple element data, wherein at least one element of the data comprises a shot and at least one other element of the data comprises a receiver, for a common element gather of traces, the method comprising: band pass filtering the traces; computing the complex trace envelope of traces of the gather; filtering out a DC component of the traces; sorting the gather by a first element line, a first element, a second element line, a second element, and an offset bin, wherein a sorted gather of traces is defined; wherein said computing and said sorting define a sorted gather of complex trace envelopes; transforming the sorted gather of complex trace envelopes into a set of velocity stack trace envelopes; wherein said traces are divergence corrected before said transforming and wherein said traces are positive bulk time shifted before said transforming; and picking events from the velocity stack trace envelopes. 6. A method for automatically correcting geometry errors in seismic data including substantially linear seismic events in multiple element data, wherein at least one element of the data comprises a shot and at least one other element of the data comprises a receiver, for a common element gather of traces, the method comprising: band pass filtering the traces; computing the complex trace envelope of traces of the gather; filtering out a DC component of the traces; sorting the gather by a first element line, a first element, a second element line, a second element, an offset bin, wherein a sorted gather of traces is defined; wherein said computing and said sorting define a sorted gather of complex trace envelopes; transforming the sorted gather of complex trace envelopes into a set of velocity stack trace envelopes; wherein said traces are divergence corrected before said transforming and wherein said traces are positive bulk time shifted before said transforming; picking events from the velocity stack trace envelopes; determining geometry error based on said picking; and correcting said geometry error. 7. A method for automatically correcting statics errors in seismic data including substantially linear seismic events in multiple element data, wherein at least one element of the data comprises a shot and at least one other element of the data comprises a receiver, for a common element gather of traces, the method comprising: band pass filtering the traces; computing the complex trace envelope of traces of the gather; filtering out a DC component of the traces; sorting the gather by a first element line, a first element, a second element line, a second element, and an offset bin wherein a sorted gather of traces is defined; wherein said computing and said sorting define a sorted gather of complex trace envelopes; transforming the sorted gather of complex trace envelopes into a set of velocity stack trace envelopes; wherein said traces are divergence corrected before said transforming and wherein said traces are positive bulk time shifted before said transforming; picking events from the velocity stack trace envelopes; determining statics error based on said picking; and correcting said statics error. 8. A method for automatically detecting substantially linear seismic events in multiple element data, and for correcting geometry and statics errors, wherein at least one element of the data comprises a shot and at least one other element of the data comprises a receiver, for a common element gather of traces, the method comprising: band pass filtering the traces; computing the complex trace envelope of traces of the gather; filtering out a DC component of the traces; sorting the gather by a first element line, a first element, a second element line, a second element, and an offset bin, wherein a sorted gather of traces is defined; wherein said computing and said sorting define a sorted gather of complex trace envelopes; transforming the sorted gather of complex trace envelopes into a set of velocity stack trace envelopes; wherein said traces are divergence corrected before said transforming and wherein said traces are positive bulk time shifted before said transforming; and picking events from the velocity stack trace envelopes; determining statics error based on said picking; correcting said statics error; determining geometry error based on said picking; and correcting said geometry error. 9. A method as in claim 1 wherein said sorting further comprises sorting the gather by offset bin. 10. A method as in claims 2 to 4 wherein said assembling comprises: computing the complex trace envelope of traces of a gather; sorting the gather by a first element line, a first element, a second element line, and a second element, wherein a sorted gather of traces is defined; wherein said computing and said sorting define a sorted gather of complex trace envelopes; transforming the sorted gather of complex trace envelopes into a set of velocity stack trace envelopes; and picking events from the velocity stack trace envelopes. 11. A method as in claims 1, 4, 10 wherein said transforming the sorted gather of traces into a set of velocity stack trace envelopes comprises: slant stack transforming of the gather of traces and maxima detecting. 12. A method as in claims 1, 3, 4, 10 wherein said transforming the sorted gather of traces into a set of velocity stack trace envelopes comprises muting the direct arrival and the data in the traces after the direct arrival and applying a τ-π transform. 13. A method as in claims 1, 3. 4, 10 wherein said picking comprises cluster maxima detection. 14. A method as in claims 1, 3, 4, 10 wherein said transforming the sorted gather of traces into a set of velocity stack trace envelopes comprises applying a τ-π transform. 15. A method as in claims 1, 3, 4, 10 further comprising divergence correcting the traces before said transforming. 16. A method as in claims 1, 3, 4, 10 further comprising band pass filtering the traces. 17. A method as in claims 1, 3, 4, 10 further comprising positive bulk time shifting the traces before said transforming. 18. A method as in claims 1, 3-8,.10 further comprising applying a dispersion filter to the direct arrival data before said computing the complex trace envelope of traces of the gather 19. A method as in claims 1, 3, 4, 10 further comprising filtering out a DC component of the traces. 20. A method as in claim 19 wherein said band pass filtering comprises source array dependent band pass filtering. 21. A method as in claim 4 wherein said assembling comprises: assigning the traces to offset bins and applying moveout correction to the traces. 22. A system for automatically detecting substantially linear seismic events in multiple element