川黔桂二叠系层序地层与油气勘探

川黔桂二叠纪的5种不同类型盆地有不同的层序充填,因此,其油气前景也不相同。总体而言,海侵体系域、凝缩层、台盆和盆地的高水位、低水位体系域以及混合台地和孤台高水位体系域上部含煤岩系是重要的烃源层。上述层序也是重要盖区,其中以海侵体系域最为重要。有利储集体及相应的潜在圈闭主要包括：(1)低水位体系域中盆底扇-斜坡扇砂体、三角洲前缘砂体、冲积扇砂体、河道充填砂体、进积复合砂体、丘滩礁组合、钙屑及混屑浊积岩等;(2)海侵体系域中的障壁滩砂体、滨岸砂体、河口湾砂体、潮控三角洲砂体、扇三角洲砂体、浊积扇砂体、滞留型陆棚砂体、海侵型生物丘礁组合、火山碎屑浊积岩等;(3)高水位体系域中的河控、浪控三角洲砂体、冲积扇-河道砂体、扇三角洲砂体、浊积扇砂体、陆屑滩坝砂体、碳酸盐滩坝砂体、丘滩礁组合、钙屑重力流沉积、白云岩等;(4)与界面有关的古岩溶储集体。

SEQUENCE STRATIGRAPHY OF PERMIAN SYSTEM IN\= SICHUANGUIZHOUGUANGXI REGION AND\= ITS OILGAS EXPLORATION

Five different kinds of basins in Permian System in SichuanGuizhouGuangxi region contain different stratigraphic sequences,so their hydrocarbon prospects are different.In general,transgressive system tracts(TST),condensed section(CS),highstand system tracts (HST)and lowstand system tracts (LST) of platform basin, deepwater basin and coalbearing carbonate formations of highstand system tract in cratonic basin and isolated carbonate platform are generally important source rocks and significant cap rocks .They include all kinds of favourable sandbodies in different system tracts:1.basinfloor and slope fans,delta front,alluvial fan,channel sandbodies,progradation complex,shoalbiohermreef complex,calcareous and mixed clastic turbidites within lowstand system tract;2.sandbodies of barrier beach,shoal,estuary,tidecontrolled delta,fandelta,turbidity fan,lag sediment,biohermreef complex,pyroclast turbidite within transgressive system tract;3.river and wave dominated deltaic sandbodies,alluvial fanchann