Evaluation On Characteristics Of Petroleum Geology And Exploration Potential Of Coastal Key Basins In East Africa

Compare with those of the western and northern Africa, the exploration level of the eastern Africa is low. However, there were many major gas field being found in the last years, which were clearly hot spots for many international big oil companies to pursue. Based on many resources like various professional petroleum database, existed petroleum geology documents, petroleum fields documents and previous research results, this paper studies the accumulation elements of three major petroleum basins like the source, reservoir, seal, accumulation play an so on through sedimentary and structural evolutions in basin and regional levels and in the view of petroleum system. Then, also in the two same levels, this paper studies the petroleum distribution accumulation rule by levels of reservoir, accumulation play and horizon. Thus, this paper analyzes the exploration potentials of basin and regional levels with explaining the regional accumulation rule and major controlling factors of petroleum accumulation.Through this research, this paper gave out these results as the following.1) The exploration level of the study area is low and the available information and documents are not sufficient. The study area concludes six main basins. In the last ten years, the gas discovery in the offshore of eastern Africa is huge and remarkable, showing a significant exploration potential.2) The eastern African margin went through three structural evolutional stages, with each sedimentary filling sequence in each stage. There are three oil and gas combinations of developed each source, reservoir and seal. The regional structural evolutionary controlled their developments and distributions.3) The study area has many sets of Jurassic and Cretaceous sources, which are widely distributed and great in quality. The reservoir developed greatly from many sets of Permian-Neogene, mainly showed as Jurassic and Cretaceous; The seal mainly includes shale sequence in both weak rift period and passive continental margin drift period.4) Through the study and research of the geology features and distribution law, this paper predicts three main exploration favorable areas in three principal basins. The Ruvuma Basin has the greatest favorable exploration layer called paleogene-neogene play. Area I should be the Cretaceous in of the Palma Bay in the east of this basin. The Tanzania Basin has the greatest favorable exploration layer called cretaceous play. Area I should be the Pande High in the centre and the Dar es Salaam Platform in the east of the basin. The Somali Basin has the most favorable exploration layer called Jurassic and Paleogene. Area I should be the coastal zone in the Mudug Basin in the centre of the basin.5) There can be favorable areas to be divided in the three major basins in result. In regional level, this paper gave out the synthetic potential level of African petroleum resources of each basin through the method of Entropy-TOPSIS model to score, evaluate and order the African coastal basins in scoring.