琼东南盆地新近系坡折带特征及其对沉积体系的控制.doc

琼东南盆地新近系坡折带特征及其对沉积体系的控制 田姗姗1, 苏明1, 何云龙1, 柳永军2 1.中国地质大学（武汉）资源学院海洋系，武汉 430074 2.中海石油（中国）有限公司天津分公司勘探开发研究院，天津 300452 摘要 坡折带是层序划分样式的重要依据。大量地震剖面的精细解剖表明，琼东南盆地新近系的坡折带可以分为构造坡折带和沉积坡折带，构造坡折带进一步分为断裂坡折带和挠曲坡折带。不同的坡折带类型控制的储层沉积特征是不同的：构造坡折带的下倾方向一般发育一系列高成熟度，较高孔隙度的斜坡扇和盆底扇，是研究区较好的储集体；缓坡的沉积坡折带控制了斜坡扇裙和盆底扇的发育，陡坡的沉积坡折带控制了滑塌体的发育，沿陆坡向海方向形成了滑块、滑塌－泥石流、碎屑流－浊流的重力流演化序列。坡折带不但控制了储层的发育，而且控制形成有利的输导系统的发育，坡折带及其控制的低位域砂体发育带是有利的勘探区带。 关键词 坡折带; 沉积体系; 储层; 琼东南盆地 中图分类号 文献标识码 A 文章编号 Patterns of Neogene Slope-break Zones and Their Controls on Depositional System in Qiongdongnan Basin TIAN Shanshan1, SU Ming1, HE Yunlong1, LIU Yongjun2 1. Faculty of Earth Resources, China University of Geosciences, Wuhan 430074, China 2. Exploration Development Research Institute of CNOOC Ltd.-Tianjin, Tianjin 300452, China Abstract The slope-break is thought to be an important criterion to distinguish the patterns of sequences. Based on the comprehensive explanation of a large number of seismic sections in the qiongdongnan basin, the neogene slope-break can be classified into two types: structural and sedimentary slope-break zones. The structural slope-break zones can be divided further into two patterns, that are fracture slope break and flexure slope break. Different patterns of slope-break control different reservoir sedimentary models. Structural slope-break zones, which are produced by the long-term activities of syndepositional faults, have always been an important factor of the depositional sequence development and the deposition process. Along the down dip direction of structural slope-break zones usually formed a series of basin floor fan and slope fan, which are characterized by high maturation and relatively high porosity. Gentle sedimentary slope –break controls the development of slope fan skirt and basin floor fan. Steep sedimentary slope –break controls the growth of slip block, which formed the gravity flow evolutionary series from slider, slip- debris flow to debris flow- turbidity current alo