苏丹迈努特盆地油气成藏机理和成藏模式

苏丹迈努特盆地是中国石油天然气集团公司在海外最大的勘探项目．快速高效发现大油田是跨国勘探的主要目的。本文在过去三年的石油地质综合研究和勘探的基础上，系统总结盆地的独特石油地质特征和油气聚集规律。迈努特盆地三期裂谷的叠置．早白垩世是最主要的一期，形成了主力烃源岩；晚白垩世弱裂谷期，沉积了一套以砂岩为主的地层；古近纪又发育一期裂谷．是主力成藏组合发育时期。特定的构造—地层特征和演化史，决定了盆地独特的油气成藏机理和成藏模式——跨时代油气聚集模式。这一模式的建立为最终发明储量达5亿吨的大油田提供了理论基础。

Formation Mechanism and Model of Oil and Gas Accumulations in the Melut Basin, Sudan

The Melut Basin is the largest exploration project operated by CNPC in overseas. To discover large oil fields quickly and effectively is the major purposes for overseas exploration project. Based on the comprehensive studies on basin structure, stratigraphic sequence and petroleum systems of the Melut Basin in past 3 years, this paper has summarized the specific petroleum geological features and raised oil and gas accumulation models for the Melut Basin. Three sequences of sediments were deposited in the Melut Basin during three rifting periods. The first sequence, which is the main hydrocarbon source rock, was formed in the first syn-rifting stage of Early Cretaceous. The second sequence, which consists mainly of sandstone, was formed in a relatively weak syn-rifting stage of Late Cretaceous. The third sequence, in which oil and gas were mainly developed, was formed in the third syn-rifting stage of Paleogene. The formation mechanism and model of oil and gas accumulation were proposed based on the specific tectonic-stratigraphic assemblages and evolution history of the Melut Basin. This model has provided a theoretical fundament for finding a large oilfield with oil in place of about 500 million tons in the Melut Basin.