Sudanese Gulf of Aden Petroleum Geology and Regional Geophysical Evaluation
OSMAN, E., B. A. RAHMAN, H. E. M. ABDELLA, and A. O. ALI, Geological Research Authority of Sudan, Khartoum, Sudan
The World Bank-executed Red Sea/Gulf of Aden Regional Hydrocarbon Study Project was organized to synthesize data on the Red Sea and Gulf of Aden basins. The primary objectives were to encourage increased hydrocarbon exploration activity within the project area by applying recent exploration techniques basin wide, and to train national geoscientists in exploration techniques. The study was carried out by task forces for each participating country, working in Cairo under the supervision of World Bank technical personnel. In addition, biostratigraphic, paleoenvironmental, and lithostratigraphic analyses by Robertson Group and geochemical studies by BEICIP were carried out on well cuttings and core samples.
The study of the Sudanese Red Sea was based on public-domain exploration data, published information, and data released by operating companies. These included reports, sections, and wireline logs from 12 wells, samples from 12 wells for biostratigraphic analysis, and samples from four wells for geochemical analysis. Interpretation was carried out on 5000 km of seismic data selected from a grid of 24,900 line-km of data. Four horizons were identified on a regional basis, including the sea floor, top, and near base of middle to upper Miocene evaporites, and approximate acoustic basement. A bathymetric map, three structure-contour maps, and three interval isopach maps were prepared using digitized picks from the interpreted seismic. Examples of each of these interpreted results will be o display.
The results show that the Sudanese Red Sea is similar to the better known, productive Gulf of Suez. In many respects, including the overall tectonic evolution, the structural style, and the Miocene-to-Holocene stratigraphic sequence. A major difference involves the development of thick depocenters of Pliocene-Holocene super-evaporite sediments, in part controlled by offsets in the topographic rift shoulder of the basin, which result in large paleodrainage basins that supplied sediment to the basin. The sediments in these depocenters are thick enough, and geothermal gradients sufficiently high, to suggest the possibility of significant hydrocarbon generation in the depocenters. This is supported by important super-evaporite hydrocarbon shows in the Tokar Delta area of the southern Suda ese Red Sea. Outside of the Pliocene-Holocene depocenters, conditions appear favorable for an attractive hydrocarbon potential in subevaporite units.
AAPG Search and Discovery Article #91007© 1991 AAPG International Conference, London, England, September 29-October 2, 1991 (2009)