Method and apparatus for detection of sand formations in amplitude-versus-offset seismic surveys
US5661697A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 18, 1995 |
| Grant date | Aug 26, 1997 |
| Priority date | — |
| Expiry date | Dec 18, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01V2210/632
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method and apparatus for analyzing amplitude-versus-offset (AVO) seismic data to distinguish sand formations, such as Morrow sands, from limestones and other similar intervals, is disclosed. For each of the traces in the survey, AVO intercept and AVO slope traces are generated, preferably after normalization of the amplitudes of the traces to account for geophone coupling variations. After normalization and conventional processing and corrections, spatial summation may be performed to further improve the traces. AVO trend lines are then generated, preferably on a weighted window basis, to generate localized trend lines against which the intercept and slope values of individual depth points may be compared. This comparison allows the plotting of AVO intercept versus AVO slope deviation from the trend line, from which sand formation interfaces may be identified by their presence in certain quadrants of the intercept-slope deviation cross-plot.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.