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Large‐offset approximation to seismic reflection traveltimes
Author(s) -
Causse Emmanuel,
Haugen Geir Ultveit,
Rommel Björn Eino
Publication year - 2000
Publication title -
geophysical prospecting
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.735
H-Index - 79
eISSN - 1365-2478
pISSN - 0016-8025
DOI - 10.1046/j.1365-2478.2000.00207.x
Subject(s) - offset (computer science) , stacking , geology , economic geology , reflection (computer programming) , geodesy , seismology , optics , mineralogy , physics , telmatology , computer science , nuclear magnetic resonance , tectonics , programming language
Conventional approximations of reflection traveltimes assume a small offset‐to‐depth ratio, and their accuracy decreases with increasing offset‐to‐depth ratio. Hence, they are not suitable for velocity analysis and stacking of long‐offset reflection seismic data. Assuming that the offset is large, rather than small, we present a new traveltime approximation which is exact at infinite offset and has a decreasing accuracy with decreasing offset‐to‐depth ratio. This approximation has the form of a series containing powers of the offset from 1 to −∞. It is particularly accurate in the presence of a thin high‐velocity layer above the reflector, i.e. in a situation where the accuracy of the Taner and Koehler series is poor. This new series can be used to gain insight into the velocity information contained in reflection traveltimes at large offsets, and possibly to improve velocity analysis and stacking of long‐offset reflection seismic data.