Favorable Play Fairways for Abu Gabra Formation in Mugald Basin, Republic of Sudan

Abstract

Muglad Basin is an intra-Craton passive rift basin related to the Central Africa Shear Zone (CASZ), which is in the Southern-Central Republic of Sudan. Three rifting-sagging cycles were developed in the basin since early Cretaceous. The first rifting sequence in the early Cretaceous Abu Gabra Formation is considered as the new play in the basin, while the favorable play fairways are unclear due to complicated sedimentary systems developed in this period. Based on the analysis of more than 60,000 km of 2D seismic, 5,000 km2 of 3D seismic data and 200 wells data in the whole basin, five third order sequences can be divided in the Abu Gabra Formation. Facies mapping showed that during the fourth (AG2) and the last (AG1) sequences lacustrine was predominant and delta systems developed in the Western Kaikang Trough, Neem, the south of Shelungo and Fula south areas. There are two sets of source rock and three reservoir-cap assemblages developed in the Abu Gabra Formation. The favorable facies for both structural and lithological traps were delta fronts with appropriate shale content, the areas were Neem-Azraq, the western flank of Bamboo-Unity sub-basins, the eastern slope of Unity sub-basin, Haraz-Diffra in Western Kaikang Trough and Fula South.