A study of the chemical aspects of Permian and Mesozoic formation waters has enabled the zones of flushing of Permian sediments by artesian waters to be clearly delineated. It has been proved that complete flushing has taken place in the southern areas of the basin where the absence of the Triassic caprock allows hydraulic interconnection between the Permian and artesian aquifers. A limited amount of flushing in the upper Permian only has occurred in those areas close to the Triassic subcrop limits. There appears to be a possible correlation between the degree of flushing and the type of hydrocarbon production, but the present study is insufficient to achieve predictability. The lack of reliable pressure data has prohibited an equally useful potentiometric study from being made to try to explain the water movement patterns, and hence possible hydrocarbon accumulations, within the basin.