Abstract

Analysis of the various traps types of the world’s giant fields indicates that about 95% of the reserves are located in visible, structure-related traps. Three-quarters of these traps are anticlines.

Although anticlinal traps predominate in continental and continental-margin basins, available data suggest that in continental margins and particularly their offshore areas a greater-than-average number of combination stratigraphic and structural traps, flowage traps, fault traps, and tensional anticlinal traps will be encountered. These more-unconventional traps may present the industry with more-difficult exploration in the future.

The “breakthrough” whereby elusive, purely stratigraphic traps may be predicted and thereby contribute a substantial share of the world’s reserves has not occurred. On the other hand, the importance of stratigraphic factors in many of the world’s giant combination stratigraphic/structural traps seems well established. These combination traps are more visible or detectable and are expected to contribute substantially to the world’s future reserves.

The distribution of various traps types show a general relation to the tectonic types of basins and the possible tectonic stresses of continental margins.