Sigi Baumgartner1, Joe Cartwright2, O Mbui Kandjoze1, Roger Swart1, Alex Warne1
(1) Namcor, n/a WINDHOEK, Namibia
(2) University of Wales (Cardiff)
ABSTRACT: New Insights into the petroleum systems of the Walvis Basin, Namibia
The Walvis Basin is a relatively unexplored sector of the Namibian continental margin located south of the prolific Angolan petroliferous basins. This major Cretaceous-Recent depositional centre covers an area of over 105,000 km2, and has a wedge-shaped geometry typical of passive margin post-rift sequences. We interpreted an extensive seismic database of 30,895 line kilometres of spec and proprietary data that was tied to three recent exploration wells.
Our interpretation has highlighted considerable untested petroleum potential. Proven high quality oil-prone source rocks exist at two stratigraphic intervals (Apto-Albian, Cenomanian-Turonian) and we have also identified source potential in an early Cretaceous syn-rift succession analogous to equivalent units in southern Angola, South Africa and South America. Maturity modeling shows that all three source intervals should have generated oil and gas in the past 10 million years. Oil shows have been identified in all three of the exploration wells and gas chimneys have been observed at numerous breaching points for the major kitchens.
Reservoir potential is proven at Apto-Albian (carbonates) and late Cretaceous-Early Tertiary (deep water clastics) levels. Additional untested plays have been mapped in both shallow and deep water positions and are reservoired in fan systems and shallow marine carbonates.
The low density of exploration wells compared to the large scale of both the areas of hydrocarbon kitchens and reservoir depositional systems means that the Walvis Basin is hugely under explored when compared to other sectors of the West African margin. Exploration wells to date prove an active petroleum system and the lack of commercial hydrocarbons in these wells does not exclude the possibility of significant accumulations in this basin.
AAPG Search and Discovery Article #90906©2001 AAPG Annual Convention, Denver, Colorado