Abstract

Integrated structural and sequence stratigraphic analysis, such as that described in this Memoir (specifically Chapters 3 and 4), represents a powerful tool for analysing a petroleum system by identifying hydrocarbon plays and constraining the regional distribution of the key elements of a play. A play is a combination of reservoir, source and seal facies which, together with a trap, may lead to hydrocarbon accumulations at a specific stratigraphic level. The geographic area over which a play is thought to extend is known as the play fairway and is usually determined by the depositional and erosional limits of the reservoir. This need not always be the case, however; play fairways based on the regional extent of a hydrocarbon source rock system or particular structural style are equally valid.

Play fairway analysis is essentially an assessment of exploration risk at a basin scale. In the past the petroleum industry has applied the concept of risk mainly at a prospect-specific level. On a larger scale, applying risk analysis to the play fairway level in frontier basins permits channelling of exploration effort into the most prospective parts of a basin. Furthermore, by combining the risks for individual plays within a basin, different basins can be ranked, allowing exploration to be focussed towards particular basins. In more mature areas, the technique can highlight new plays in under-explored parts of the basin or, equally, provide an indication that the basin has very little remaining prospectivity and that it may be time to withdraw.

Figure 43 Illustrates an Idealised model of the main potential