Abstract

Mukta and Bassein formations of Bassein field are believed to be separate reservoirs with a thin limestone-shale sequence in between acting as a barrier. However a considerable pressure drop in Mukta formation has been observed over these years, although there is no significant conscious production from this formation. On the other hand the pressure drop in Bassein formation is less than what is expected on the basis of material balance / simulation studies carried out by different agencies (with in-place of Bassein formation as 240 BCM). A better history match is achieved if the in-place of Mukta (34 BCM) is also added into the in-place of Bassein. This is a prima facie indication that these two reservoirs are not totally isolated, as believed hitherto, and there exists some communication between them