The Betoota No. 1 well was drilled by Delhi Australian Petroleum Ltd, Frome-Broken Hill Company Pty Ltd, and Santos Limited, in far southwest Queensland to a total depth of 9,824 feet. Drilling was commenced on 22nd December 1959 and the well was completed on 18th April 1960 as a dry hole. The rig used was a National 130 owned by Delta Drilling Company. Delhi Australian Petroleum Ltd, as the operating company, supplied the supervisory, engineering, and geological personnel. A comprehensive programme to obtain all data relative to the hydrocarbon potential of the strata penetrated by the drill bit and stratigraphic information concerning the geological history of the area was diligently carried out. The operation also provided for a complete programme of electric and mud logging, testing and coring, carried out by the operating company and their contracted service
companies.
The Betoota No. 1 well established the presence of 5,757 feet of Mesozoic strata overlying 4,067 feet of sediments of probable Palaeozoic age at the site of the bore hole. Several showings of hydrocarbons were detected in sediments between 4,400 feet and 5,757 feet. Mter testing and examination of all evidence, they were considered to be noncommercial. From 3,450 feet to 5,757 feet some zones exhibiting very good porosity were encountered, but all were found to be water-bearing. Shales of both marine and brackishwater origin, regarded as suitable source rocks, occurred in the well between 1,350 feet and 3,245 feet and between 5,000 feet and 5,757 feet. The rest of the section penetrated was
composed of sediments whose origin did not suggest conditions of accumulation likely to foster the generation of fluid hydrocarbons.
