Mount Salt No. 1 Well was located approximately twelve miles south-west of Mount Gambier in the South Australian part of the Otway Basin. The well was drilled by Reading and Bates (Australia) Pty Ltd for Oil Development No Liability, to a total depth of 10,044 feet. DrillIng commenced on 9th May, 1962 and was completed on 21st September, 1962. A full programme of logging, testing, and coring was undertaken.
After passing through about 3260 feet of Oligocene and Eocene-Palaeocene sediments, the well entered a thick sequence of Upper Cretaceous sands, siltstones and clays that persisted to total depth. The upper part of this section has been correlated with the (?) Paaratte Formation, and the well bottomed in either basal Upper Cretaceous or uppermost Lower Cretaceous marine or brackish strata that probably correlate with either the top of the Waarre Formation or the Flaxmans Beds of Flaxmans No. 1 Well. The base of the Upper Cretaceous is not clearly defined, and no definite conclusions as to the correlation of the section below the Knight Group (? 590 to? 3260 feet) have been advanced.
Mount Salt No. 1 Well was drilled to test the petroleum potential of Cretaceous sediments in a closed structure detected by photogeology and proved by a structure drilling programme. Traces of crude oil were detected by core analysis and a show of gas was recorded from the interval 9830 to 9848 feet. Five drillstem tests were attempted but only one, over the interval 9813 to 9892 feet, was successful, obtaining 4070 feet of highly saline water.
The stratigraphic drilling operation at Mount Salt No. 1 was subsidized under the Petroleum Search Subsidy Act 1959-1961, from 980 feet to total depth.