Geologically driven seismic reprocessing: the Val d'Agri case history

A case history is presented describing the revision of the 3D seismic volume for an onshore hydrocarbon field in Italy. One of the key elements for the success of the project was the contribution of the geological information to seismic data processing and imaging, which was deemed since the beginning as an indispensable guide to drive and constraint the seismic reprocessing. In particular, two critical steps in which the integration between geology and geophysics played a relevant role are discussed here: the estimation of static corrections for data preconditioning before imaging, and the velocity model building for depth imaging. The paper includes also a proposal for a stratigraphic revision of the allochthonous sequence of the Val d'Agri area. The outcomes of the project comprised the release of a reprocessed seismic volume in time domain, the creation of the first Pre-Stack Depth Migrated volume of the field, together with the revision of some stratigraphic boundaries, and created the conditions for a revision of the geological model of the field. The project lasted approximately two years and was executed by a multidisciplinary group comprising geophysicists, geologists, sedimentologists, and structuralists. The collaboration with Shell, joint venture partner, was also an important factor for the success of the project.