中非穆格莱德盆地福拉凹陷石油地质特征及勘探前景

Petroleum geologic characteristics and exploration prospect of Fula sub-basin in Muglad basin.

穆格莱德盆地福拉凹陷是一个在中非走滑断裂带控制下发育而成的中、新生代内陆断陷湖盆。自早白垩世至第四纪发育了 3个各具特点的沉积旋回 ,早白垩世沉积的AG组湖相富含有机质的泥岩、页岩分布广泛 ,评价为好—极好烃源岩 ;早白垩世后期至晚白垩世发育了多套储盖组合 ;该凹陷构造格局简明 ,自南而北表现出“东断西超”→“不对称地堑”→“西断东超”的变化特点 ,发育有 5个二级构造带 (南部断阶带、南部次凹、中部构造带、北部次凹及北部断阶带 ) ;构造圈闭发育 ,以滚动背斜及断鼻为主 ,且成带分布 ,形成了 4个主要的成藏模式 ;具有较大的油气资源背景及良好的勘探前景 ,预测 3～ 5a内在福拉凹陷可探明石油地质储量 1 .1× 1 0 8～ 1 .7× 1 0 8t,可建成年产原油 3 0 0×10 4～ 5 0 0× 1 0 4t的生产能力。图 5参

Fula sub basin is a Mesozoic and Cenozoic continental rifted basin, which is controlled by the Center Africa Strike slip fault. There has been three sedimentary cycles developed from Cretaceous to Quaternary. AG Formation lacustrine facies shale and claystone deposited during early Cretaceous is of organic rich, which is rated as good to excellent source rock. After that, there have been two assemblages of reservoir and seal in Cretaceous formation. Fula sub basin has plain and clear structural framework. There are three positive and two negative structural units in this sub basin.Structural types are mainly roller over anticlines, faulted noses and so on. These traps distributed in belts. 4 reservoir forming zones are identified. This sub basin is of great hydrocarbon resource and prospects, has a good exploration potential.