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Bongor盆地和Lake Chad盆地是位于非洲中部且地理位置较近的盆地,但两者在烃源岩的发育特征方面却存在着明显的差异:Bongor盆地的烃源岩主要发育于下白垩统湖相泥岩中,Lake Chad盆地的烃源岩则主要发育于上白垩统海岸—滨海相泥页岩中。通过对2个盆地的区域构造背景分析,认为烃源岩发育的差异性是2个盆地所处的区域应力场不同所致。Bongor盆地位于中非裂谷系,其油气成藏特征受中非剪切带的影响;Lake Chad盆地属于西非裂谷系,油气成藏特征受西非张裂带的影响。中非裂谷系和西非裂谷系2大不同的区域地质背景,造就了2个盆地差异性较大的烃源岩发育特征,了解这种油气成藏的差异性特征对中国南海未来的油气勘探有一定的启发作用。
The Bongor and Lake Chad basins are geographically located basins in central Africa. However, there are obvious differences in the developmental characteristics of source rocks: the source rocks of the Bongor Basin mainly develop in the Lower Cretaceous lacustrine facies In the mudstone, the source rocks of the Lake Chad Basin mainly develop in the Upper Cretaceous coast-coastal shale. By analyzing the regional tectonic settings of the two basins, it is considered that the difference of source rock development is caused by the difference of the stress field in the two basins. The Bongor Basin is located in the Central African Rift System and its hydrocarbon accumulation characteristics are influenced by the Central African shear zone. The Lake Chad Basin belongs to the West African Rift System. The hydrocarbon accumulation characteristics are affected by the West African Zhangjiahekou zone. The two different regional geological backgrounds of the Central African Rift System and the West African Rift System have resulted in the developmental characteristics of the two source rocks of relatively different types of basins. Understanding the different characteristics of hydrocarbon accumulation, the future oil and gas in the South China Sea Exploration has some enlightenment.