Petroleum geologic property and reservoir-forming pattern of Melut Basin in Sudan

Melut Basin is a large-scale basin of the Cretaceous-Paleogene sediment in the southeastern Sudan.Two strong rifting phases were developed during the Early Cretaceous and Paleocene,and one weak rifting phase was developed in the basin during the Late Cretaceous.Consequently,the main source rocks were deposited in the Lower Cretaceous and the main play was developed in the Paleocene.Based on analogue of seismic reflection characters and sequence stratigraphy,the Lower Cretaceous in the Northern Melut Sub-Basin(NMSB) was deduced as the main source kitchen.The half-graben style of NMSB made the northeastern gentle slope become the most advantageous accumulation area for hydrocarbon.Furthermore,the lower geothermal gradient controlled the critical moment of petroleum system in the Late Eocene,which provided enough hydrocarbons charging into the Paleocene.Accordingly,the pattern of reservoir-forming in Melut Basin was established.This pattern is quite different from adjacent Muglad Basin in Sudan and Bohai Bay Basin in China.Then,a more reasonable estimation of petroleum resources and more scientific exploration strategy in Melut Basin of Sudan were made on the pattern of reservoir-forming,and a Great Palogue Oil Field was successfully discovered by CNPC.