Abstract The use of geophysics for exploration appraisal began as a tool for reservoir definition, description of continuity, and estimation of thickness variations across the prospect. The primary application of seismic data was to define reservoir limits and compartments, and analysis techniques were limited to poststack data. That has been changing slowly but steadily in the past decade. For reservoir appraisal, seismic techniques have expanded to the prestack domain, contributing to the understanding of subtle reservoir variations, including lithology and fluid change. Electromagnetic methods are used to detect hydrocarbons directly at the reservoir scale.