Senex Energy Limited (Senex, ASX: SXY) has delivered further success as part of its 30+ well drilling program for 2013/14, with Acrasia-6 extending the productive life of Acrasia oil field in the north east of South Australia's Cooper-Eromanga Basin.
Acrasia-6 is a deviated appraisal well located approximately 300 metres south of Acrasia-1, which has produced from the mid Tinchoo Formation since 2002. The appraisal well aas designed to assess the extent of the Acrasia Hutton Sandstone oil accumulation, produce unswept oil in the Birkhead, Poolowanna and Tinchoo sandstone reservoirs, and evaluate the potential of the Arrabury Formation.
Acrasia-6 spudded on 14 November 2013 and reached a total depth of 2,369 metres. During drilling, good oil shows were evident throughout the sandstones of the Hutton, Birkhead, Poolowanna and Tinchoo formations. Interpretation of wireline logs indicate approximately 31 metres of net pay across these four target zones with an additional 15 metres of probable pay calculated for the Birkhead and Tinchoo formations. Net pay in the Arrabury Formation will not be known until the results of the core analysis are available to calibrate the wireline logs.
ABOUT ACRASIA OIL FIELD
Acrasia oil field is located 125 kilometres north east of Moomba, near the Queensland border. Acrasia-1 was the first well drilled by Stuart Petroleum Limited (Stuart), a South Australian oil production company acquired by Senex in February 2011. The well was drilled in March 2003 and was brought online as an oil producer in July the same year after intersecting oil in the Birkhead, Hutton, Poolowanna and Tinchoo reservoirs. Stuart subsequently drilled four successful development wells at the field, which has produced approximately 840,000 barrels of oil to date.
In 2013, structural remapping and oil-in-place calculations by Senex indicated significant potential for additional oil production from the field. In August, Senex drilled the Acrasia-7 development well to maximise the recovery of unswept oil from the mid Tinchoo Formation and evaluate the potential of the Birkhead, Hutton and Poolowanna formations. The well was cased and suspended as a future oil producer in September after intersecting interpreted net oil pay of 6.3 metres in the Tinchoo and Poolowanna formations, and is expected to commence production in December 2013.
ARRABURY FORMATION POTENTIAL
During drilling of Acrasia-6, Senex cut core over an interval of 34 metres from 2,262 metres to 2,296 metres through the interbedded sandstones and shales of the Arrabury Formation. The coring program was designed to enhance understanding of the reservoir and calculate rock properties. Analysis of the core indicates the presence of oil in the Arrabury Formation at Acrasia-6. In 2002, the Acrasia-2 appraisal well produced at a rate of 430 barrels of oil per day from the Arrabury sandstone, but was not able to be brought onto production. Senex is now evaluating options to exploit this oil pool and assess the potential for similar Arrabury accumulations in the region.
