Method and system for applying dispersive normal moveout corrections to seismic survey signals
US5933789A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 12, 1996 |
| Grant date | Aug 3, 1999 |
| Priority date | — |
| Expiry date | Nov 12, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F17/10
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method and computer system for deriving and applying normal moveout phase and time shift corrections to seismic survey traces is disclosed. Normal moveout time-shift corrections are first applied to traces in a common midpoint (CMP) or common depth point (CDP) gather, based upon stacking velocity analysis applied to envelopes of the traces. One offset in the survey, preferably the maximum offset, is selected as the reference point; the NMO time shift at this reference offset is then selected as a reference NMO time-shift. The traces in the gather are each phase-shifted based upon iterated reference phase dispersion values at the reference offset, times the ratio of the normal moveout time-shifts for the trace in the gather to that of the reference offset (raised to a power). Semblance analysis is performed to identify, for each point in normal incidence time and thus for each reflective event, the optimum reference phase dispersion value. Phase corrections, based upon the optimum reference phase dispersion value as a function of normal incidence time multiplied by the ratio of the normal moveout trace and reference time shifts, are then applied to the traces in the gather. Interp…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.