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MODEL‐BASED STACK: A METHOD FOR CONSTRUCTING AN ACCURATE ZERO‐OFFSET SECTION FOR COMPLEX OVERBURDENS 1
Author(s) -
LANDA E.,
THORE P.,
RESHEF M.
Publication year - 1993
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 - 10.1111/j.1365-2478.1993.tb00877.x
Subject(s) - offset (computer science) , stacking , stack (abstract data type) , geology , inversion (geology) , algorithm , tracing , prestack , earth model , a priori and a posteriori , computer science , tectonics , seismology , physics , philosophy , epistemology , nuclear magnetic resonance , programming language , operating system
A bstract The interpretation of stacked time sections can produce a correct geological image of the earth in cases when the stack represents a true zero‐offset section. This assumption is not valid in the presence of conflicting dips or strong lateral velocity variations. We present a method for constructing a relatively accurate zero‐offset section. We refer to this method as model‐based stack (MBS), and it is based on the idea of stacking traces within CMP gathers along actual traveltime curves, and not along hyperbolic trajectories as it is done in a conventional stacking process. These theoretical curves are calculated for each CMP gather by tracing rays through a velocity‐depth model. The last can be obtained using one of the methods for macromodel estimation. In this study we use the coherence inversion method for the estimation of the macromodel since it has the advantage of not requiring prestack traveltime picking. The MBS represents an accurate zero‐offset section in cases where the estimated macromodel is correct. Using the velocity–depth macromodel, the structural inversion can be completed by post‐stack depth migration of the MBS.