COMPOSITIONAL DATA : GAS : GAS PROPERTIES Puffin Fm RFT ...

RESERVES:Initial Oil: 56.6 MMbbls (includes Cassini)Remaining Oil: 2.6 MMbbls (at end 2001)Source: Northern Territory Department of Business Industry and ResourceDevelopment, 2002.REMARKS:A residual oil column has been interpreted below the oil/water contact in all the Challis wells. Maximumresidual oil column of 57 m is present in Challis-5.Challis-8 and Challis-9 were completed as Pollard Formation oil producers.Commercial production of oil from the joint development of the Challis and Cassini oil fieldscommenced in 1989. Eleven sub-sea completions are connected to an FPSO. The FPSO is a purposebuiltmoored barge designed as a floating oil production storage and offloading facility.At date of publication, The Challis and Cassini oil fields were held under Production Licenses AC/L2and AC/L3.STRATIGRAPHY (Challis-1) :AGE UNIT FORMATION TOP(mKB)TERTIARY WOODBINE Undifferentiated 116.2GROUP Hibernia Formation 478.0CRETACEOUS BATHURST ISLAND GP Undifferentiated 984.0TRIASSIC SAHUL GROUP Undifferentiated 1387.0STRATIGRAPHY (Challis-14) :AGE UNIT FORMATION TOP(mSS)Barracouta/Oliver Fms 72.5TERTIARY WOODBINE Hibernia Formation 451.5GROUP Grebe Sandstone 689.5Johnson Formation 779.5Borde Formation 975.5BATHURST Fenelon Formation 1091.5CRETACEOUS ISLAND Gibson Formation 1167.5GROUP Woolaston Formation 1238.5Jamieson Formation 1239.5JURASSIC FLAMINGO GROUP Echuca Shoals Fm 1348.5TRIASSIC SAHUL Challis Formation 1363.0GROUP Pollard Formation 1545.5