Ssm,The basic point is that most basins in Australia don't...

Ssm,

The basic point is that most basins in Australia don't have these prolific fold/thrust belts that are found in Asia and the Middle East. Fold belts have a lot of geological stress and hence pressure, these also predominantly exist in areas close to major fault zones which Australia doesn't really have.

These fold/thrust belts also create a lot of fractures due to the brittle nature of some rocks. Hence high pressures and fractures creating difficult drilling conditions. Even above reservoirs there are pressurised and fractured zones that can contain mud or gases.