不同类型盆地层序格架与油气圈闭——以西南地区上古生界为例

西南地区上古生界层序格架与油气圈闭关系研究表明,不同成因类型沉积盆地的层序成因格架和内部构型各异;不同层序的油气圈闭特征及分布存在明显差异.总体而言,该区上古生界层序格架与油气圈闭之间的关系集中表现在分布于层序成因格架中的各种隐蔽的“微型”非构造圈闭.这些非构造圈闭主要包括:(1)受层序界面控制的古岩溶圈闭;(2)与LST有关的混屑浊积岩、盆底扇岩性圈闭;(3)与TST有关的海侵型丘礁滩组合圈闭、浊积扇岩性圈闭、河口湾-浅滩-潮控三角洲砂体岩性圈闭;(4)与HST有关的扇三角洲-冲积扇岩性圈闭、河控三角洲岩性圈闭、丘礁白云岩岩性圈闭、钙屑重力流沉积岩性圈闭;(5)碳酸盐孤台岩性尖灭圈闭.

RELATIONSHIP BETWEEN OIL-GAS TRAP TYPE AND SEQUENCE FRAMEWORK OF UPPER PALEOZOIC, SOUTHWEST CHINA

Based on the research on relationship between oil and gas trap distribution and sequence framework of Upper Paleozoic in Southwest China,the authors suggest that oil-gas trap type,characteristics of sequence genetic framework and internal architecture of distinct genetic basins are quite different. On the whole, non-structure traps within sequence framework of Upper Paleozoic in Southwest China mainly include; (1) paleokarstic trap associated with sequence boundary; (2) lithologic trap of mixed clastic turbidite-basin floor fan within LST; (3)bioherm reef complex trap,lithologic trap of turbidite fan and estuary-shoal-delta within TST; (4)lithologic trap of fan delta-turbidite fan,lithologic trap of delta,lithologic trap of bioherm-reef dolostone and calcareous clastic gravity flow sediments; (5)lithologic trap of isolated carbonate platform.