Abstract

There was an urgent requirement in south Tapti field to get two in-fill wells in the shallow reservoir zones known as zone I and zone-II to maintain the falling production. Zone II has got three sands (II-A, II-B, and II-C) that are not resolved on seismic at many reservoir locations and hence manual mapping of seismic amplitudes was not effective. The key element of this study was to quickly delineate and map the zone II sands to help identify the infill locations. This was successfully achieved by adopting a methodology that involves identification and optimization of relevant seismic attributes and their hierarchy. Hierarchy itself is dependent on the stratigraphy of the target zone which, in this case is known to be fluvial distributary channels and tidal bars on a coastal plain. The selected/ identified attributes were ranked and studied in three groups of hierarchical order- First, Second and Third order attributes.