Click to view page image in pdf format.
7th Middle East Geosciences Conference and Exhibition
Manama, Bahrain
March 27-29, 2006
1 AGRI, KACST, PO Box 6086, Riyadh, 11442, Saudi Arabia, phone: +966-1-4813323, fax: +966-1-
4813523, [email protected]
2 Schlumberger Cambridge Research, Cambridge, CB3 0EL, United Kingdom
We apply a methodology for seismic data redatuming in the presence of rugged topography and geophysically complex
near-surface using a new prestack operator, the Topographic Datuming Operator (TDO), on synthetic and real data. TDO,
unlike static corrections, allows for the movement of reflections laterally to their true locations corresponding to the new
datum level. Thus, it mitigates mis-positioning of events and velocity
bias introduced by the unphysical time-invariant
vertical shifts carried out by static corrections. The application to synthetic data of the proposed methodology demonstrates
the ability of TDO to remove the detrimental effects on the data of a rugged topography and a complex overburden similar
to those encountered in the Arabian Peninsula. As a result, conventional poststack processing and
migration
yields a good
image of the deeper low relief structures. Using shallow velocities estimated from refracted events, TDO provides a superior
continuity to reflections and focusing for real onshore Arabian Peninsula data than that obtained from conventional static
corrections. The marginal additional computational cost and the possibility of estimating, after TDO redatuming, stacking
velocities that are not affected by a spurious positive bias as in the
case
of static corrections to a deep datum are the other
advantages of the proposed methodology.