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

APPRAISAL AND DEVELOPMENT DRILLING :Octavius-1. 37.5 o API oil was detected over the shale shakers while drilling the interval 2,715 – 2,825mKB. Tight hole problems encountered at this time suggested the oil was being swabbed from a faultplane intersected at 2,715 mKB. Octavius-1 was plugged back and sidetracked at 2,150 mKB (Octavius-1ST-1).Octavius-1ST-1. The drill string became stuck at 3,015 mKB and the well was plugged back andsidetracked at 2,778 mKB (Octavius-1ST-2).Octavius-1ST-2. The drill string became stuck at 3,151 mKB and the well was plugged back andsidetracked at 3,013 mKB (Octavius-1ST-3).Octavius-1ST-3. The drill string became stuck at 3,204 mKB and the well was plugged back andsidetracked at 3,100 mKB (Octavius-1ST-4).Octavius-1ST-4 was abandoned at 3,142 mKB due to a stuck drill string.Octavius-2 was drilled 2 km southwest of Octavius-1. Oil was detected in the drilling mud at the shaleshakers at 2,933 mKB and 3,040 mKB and was associated with gas peaks of 253 and 159 unitsrespectively. A residual oil column was interpreted to be present in the Plover Formation (white,streaming cut fluorescence and brown oil staining in sidewall cores over the interval 3,193 – 3,262mKB). The oil is thought to have been subsequently displaced by late gas migration. Octavius-2 wasplugged and abandoned due to poor reservoir quality in the Plover Formation.In 1998, Tenacious West-1 was drilled in adjacent exploration permit AC/P4(R1) to appraise thesouthwestern extension of the Tenacious/Octavius discovery. Tenacious West-1 was plugged back to1,958 mRT from 2,150 mRT and sidetracked. Tenacious West-1/ST-1 kicked off at 2,102 mRT andwas drilled to a measured depth of 3,030 mRT (2,913 mTVDRT).RESERVES:Oil:5.9 MMbblsSource: Northern Territory Department of Business Industry and Resource Development,1999.REMARKS:A deviated well, Tenacious-1 ST1, was kicked off at 2,030 mKB and drilled to a depth of 3,020 mKB totest the updip potential of the Tenacious feature. A DST over the intervals 2,806-2,817 m and 2,822-2,834 m flowed oil at 7,667 bbls/day and gas at 113,834 m 3 /day.In 1990, Western Mining Corporation Ltd drilled Octavius-1 (including four sidetracks) and encounteredoil shows in the Plover Formation. In the following year, an appraisal well (Octavius-2, drilled 560 msoutheast of Tenacious-1) recovered gas on RFT from the Plover Formation.It is thought that Octavius-2 intersected the same hydrocarbon accumulation tested by Tenacious-1.