A Collaborative Approach to Seismic Interpretation for Offshore Field Development—A Case Study

Abstract

Santos operates several gas fields in the offshore Otway Basin in water depths around 100m. The gas is reservoired in late Cretaceous sandstones with porosities typically of 18–25% and permeabilities typically of 10–700mD at approximately 1800mss depth. A 3D seismic survey was acquired across the fields and initial exploration and development wells were located using a time migrated 3D volume. A recent development well drilled on the interpreted crest of the field delivered lower productivity than expected with indications of produced water from an unknown source. This result indicated greater complexity than originally envisaged: to address this it was decided to reprocess the seismic volume using Pre-Stack Depth Migration (PSDM) and, at the same time, establish a multi-disciplinary team to take an integrated approach to understanding the field. This paper discusses how a collaborative approach, combining holistic 3D structural interpretation, rock physics modelling, fluid dynamics (incorporating petrophysical and SCAL data) and production data elicited new ideas to explain the field performance and identify further development opportunities

AAPG Datapages/Search and Discovery Article #90217 © 2015 International Conference & Exhibition, Melbourne, Australia, September 13-16, 2015