Final report for Sturt Plateau Bitumen (SPB) Project, Geophysics and Drilling Collaborations Program

Abstract

EL's 25596 - 25599 were applied for by Dunmarra Energy Pty Ltd on the basis of 'coal' being struck during drilling of a water bore. The material was later found to be bitumen, most likely a grahamite (Matthews, I., Evans, P. and James, A., 2007A). A core drilling program of four holes with a maximum depth of 75 m was originally planned (Matthews, I., Evans, P. and James, A., 2007B). However, lack of available drill rigs and concerns with core recovery using standard diamond drilling methods resulted in the use of reverse circulation down-holehammer drilling with large diameter (100 mm) diamond tails being implemented. A total of six holes for 352 m were completed. Drilling results were disappointing. Multiple, very thin bitumen seams were struck in SPBP No.3, 500 m south-west of discovery water bore, RN 32962. SPBP No.3, 18 m north of the discovery bore struck less than 0.2 m of total bitumen over a 3 - 4 m section of highly fractured and weathered/leached basalt. Due to the poor results, no coring was undertaken. Although there is evidence that the bitumen within the basalt is widespread, it is likely to be difficult to determine effective targeting techniques. If the Velkerri Formation is the source rock as is postulated, it follows that bitumen may also have been trapped at the base of the Antrim Plateau Volcanics on the basal unconformity surface. Once again, target generation would be difficult. Further interpretation of the existing geochemical data sets may assist further in the confirmation of the bitumen source rock.