Monitoring pressure depletion and improving geomechanical models of the shearwater field using 4D seismic

Dedicated 4D seismic data have been used to investigate horizontal and vertical compartmentalization in the high pressure, high temperature (HPHT) Shearwater Field in the U.K. Central North Sea. Geomechanical modeling and conversion of model results to synthetic seismic time shifts allow quantitative comparison of models with real 4D seismic time shifts. Drilling in and around heavily depleted reservoirs is very challenging, and matching the geomechanical model to all data sets (including 4D) provides the best possible constraints on the likely stress fields an infill well will encounter in the overburden and the reservoir. © 2007 Society of Exploration Geophysicists.