Print this pageSequence Stratigraphy Redefines Post-Karroo Basins of Mozambique and Their Petroleum Potential
KIDSTON, ARTHUR G., JAVED IQBAL, GUILHERMINO FORTES, and CARLOS ZACARIAS
The Indian Ocean continental margin of Mozambique comprises two basins filled with up to 10 kms of Mesozoic and Cenozoic sediments lying unconformably on Jurassic Karroo volcanics.
Several episodes of rifting from the Gondwana breakup to the Tertiary East African Rift System are superimposed with azimuthal intersections resulting in structural trends not all of which have been explored.
The Mozambique Basin predominates covering an area of about 300,000 km{2}, mostly onshore and not explored since 1971. Five major sequences have been mapped to understand the basinwide stratigraphic framework. The segregation between shallow vs deep water facies is critical for predicting reservoir/source zones especially in the onshore Cretaceous section in the Limpopo to Beira area.
Despite low drilling density, three significant onshore gas discoveries (with condensate) have been made in Upper Cretaceous shelf sands at Pande, Buzi and Temane with the former delineated and slated for development.
The Zambezi River Tertiary delta reflects eustatic controls on deposition creating both clastic and carbonate targets. Six wells were drilled prior to 1970, all predating 25,000 km of modern seismic.
The smaller Rovuma Basin in the north contains marine Jurassic on top of Triassic/Jurassic rift sediments. In addition to normal margin structuring this basin has been wrenched by its proximity to the Davie Fracture Zone. It remains virtually unexplored with one well drilled in an area of almost 30,000 km{2}.