This report summarises basic data relating to hydrocarbon characteristics and discoveries in the Permo-Triassic Cooper Basin. In general, for petroleum production and engineering purposes, the recognition of whether a discovery consists of oil or gas or both is not always a simple matter to resolve. The hydrocarbon contents of a reservoir are defined at the conditions of temperature and pressure in the reservoir, and may differ from the phases present at the surface, and change with production handling. Thus some gas flows from the Tirrawarra Sandstone in the base of the Cooper Basin sequence are considered to exist as part of the oil phase in the reservoir, and this gas type is referred to as solution gas or associated gas. Conversely, liquid hydrocarbons, which are often accompany Permo-Triassic gas flows, exist in the gas phase in the reservoir. This liquid is referred to as condensate. Moreover, referring a hydrocarbon phase seen at the surface to putative oil or gas in the reservoir may not be possible without performing analytical work on flow samples, this usually being pressure-volume-temperature (PVT) modelling. In the absence of such analysis some doubt may and often does remain about the phase classification of a hydrocarbon discovery. Hydrocarbon discoveries in the Cooper Basin have been made in almost every formation, although oil discoveries are more restricted in both stratigraphic distribution and size, than gas discoveries. To date, the Toolachee and Patchawarra formations contain the majority of hydrocarbons discoveries. A petroleum pool discovery well is one which recovered a measurable amount of oil, or flowed gas at a significant rate. More rarely, untested hydrocarbon saturation of a reservoir may be indicated from analysis of electric well logs. For the purpose of evaluating the geological controls on Cooper Basin hydrocarbon distribution, in this report some wells with marginal (20-50%) hydrocarbon saturations, or tight accumulations, have also been included. Petroleum discoveries have been tabulated according to the discovery well and date, best flow or recovery, and where available, some hydrocarbon type parameters. The reported data are derived mainly from summaries of well test results entered on the Delhi Petroleum geological data base, or have been obtained from petroleum production records or well log evaluation outputs. Where the depth interval of a well test spanned more than one formation, it has usually been possible to assign any discovery to only one formation on the basis of log analysis (reservoir sand position and hydrocarbon saturation).