Determining geometry of salt diapirs by depth modeling of seismic velocity pull-up

Depth modeling of seismic data is used to constrain the geometry of salt diapirs. Subsalt horizons appear as velocity pull-up reflectors in seismic sections due to the high velocity of salt. Iterative depth modelling based on extension of top salt, the velocity pull-up, and interpreted subsalt geometry give the main geometry of the salt diapir. The method has been applied to salt diapirs in the Nordkapp basin on the Barents shelf. The results suggest that salt diapirs in this basin have broad overhangs fed by narrower stems. In the absence of wells, the present method offers a simple and time efficient tool in hydrocarbon exploration. -from Authors