Coleman, J. L.¹
(1) Coleman Geological Services, Richmond, TX

ABSTRACT: Comparative Analysis of the Petroleum System Potential of Delta-front Deep Water Reservoirs of the World’s Great Rivers

Wescott (1992) showed that large deltaic depositional systems had the capacity to become large petroleum systems. He suggested that large deltaic petroleum systems, just by their size and genetic nature, might be lucrative hydrocarbon provinces. A logical extension to this thesis is that large pro-delta submarine fan systems might also host large petroleum systems. Nineteen large river systems from around the world were examined to assess their potential as sites of large deep water petroleum systems.
As a progressively maturing petroleum province, the deep water Mississippi River area contains significant petroleum systems, followed in degree of exploration maturity by the Congo River deep water area. Recent discoveries off the Nile River, indicate that it, too, will be a major deep water producing area, though, perhaps, more gas-centered than oil. Several significant discoveries in the deep water Niger Delta indicate the strong potential there for a major deep water producing system.
The deep water areas of other rivers in the study (Mackenzie, Rio Grande, Magdalena, Orinoco, Amazon, Zambezi, Indus, Ganges, Irrawaddy, Mekong, Pearl, Yellow, Yangtze, Yukon, Rio de la Plata) have highly variable potential and risk for eventual, possible development.
Based on this study, the factors leading to significant production appear to be the presence of rich, relatively wide-spread Jurassic or Cretaceous source rock beneath a thick, Cenozoic deltaic - submarine fan clastic section, which causes the source rock interval to proceed into the oil generation geothermal window. Salt and/or shale diapiric structures assist hydrocarbon fetch and vertical migration pathways.

AAPG Search and Discovery Article #90026©2004 AAPG Annual Meeting, Dallas, Texas, April 18-21, 2004.