【摘要】 尼日利亚深水区地貌形态、层序地层结构、钻井岩性及岩心特征、三维地震振幅图等资料显示,深水沉积以低位海底扇为主。浊流具有重力流和牵引流的双重属性,不仅形成了扇状的朵叶和分枝状的水道体系,还通过其内部环流形成高弯度的水道体系。浊积水道的形态主要受地形坡度控制,其中高弯度水道主要发育在缓坡地段。区内陡缓相间的阶梯状地形使海底扇总体呈拉长状,其中上扇区以水道为主,下扇区以朵叶为主,中扇区为水道与朵叶的叠合体,且视海平面变化和物源的供应情况而出现活动、前积与废弃、退积等不同的组合方式。水道、决口扇、决口朵叶以及各类侧向或垂向叠加复合体是区内主要的储集体类型。根据重力流水道及扇体的成因特点建立的沉积模式,能够使该区储层研究更加准确和高效。更多还原

【Abstract】 The deposition in Nigeria deep-water area is predominated by lowstand submarine fans according to data of topography,sequence stratigraphy,drilling lithology,core and 3D seismic amplitude in the area.The turbidite deposits are of both gravity flow and traction flow,forming not only fan-shaped lobes and dendritic channels,but also high tortuous channel systems by its inner circulation flow.The morphology of turbidite channels is mainly controlled by topographic gradient,and the high tortuous channels mostly developed in gentle slopes.The abrupt-gentle alternated and stepped topography has resulted in elongation of the submarine fan bodies,with their upper fan predominated by channels,lower fan by lobes and middle fan by superposition of channels and lobes;and various patterns of activity-progradation or abandonment-retrogradaion have occurred,depending on sea level changes and provenances.Channels,crevasse splays,lobes and their various vertical or lateral superposed complexes have constituted major types of reservoir in this area.The deposition model built from origins of gravity flow channel and fan can make reservoir research more accurate and efficient in the area.更多还原