东海春晓构造成藏条件浅析

Gas-pool Forming Condition of the Chunxiao Structure, the East China Sea

王岚 谢月芳 张纪

WANG Lan XIE Yue fang ZHANG Ji

上海海洋石油局 规划设计研究院, 上海 200120

Planning & Designing Institute of Shanghai Offshore Petroleum Bureau, Shanghai 200120

春晓构造位受盆地构造演化发展格局的影响,它的发展同样经历了裂谷、坳陷与区域沉降三个演化阶段,春晓构造表现为两期形成的复合型背斜。春晓地区存在多套良好的烃源岩系,沉积相研究表明生储盖条件配置良好。反转构造表现为上部的背斜圈闭直接覆盖在原先裂谷期发育的凹陷之上,生成的油气沿断层垂向运移进入圈闭,成藏配置优越。隆升作用使得天然气析出并向浅部运移,可能是春晓构造天然气运移的主要机制。因此,构造沉降之后的回返期 (即渐新世末和中新世末 )是天然气向构造圈闭排出并聚集的主要运聚成藏期

Affected by structural development frame of the Xihu Trough, Chunxiao Structure underwent rift, depression, and regional subsidence three development stages and appeared as two phase super-imposed anticline. Chunxiao boasted several sets of good source rock. Depositional facies research showed that excel-lent source-reservoir-caprock assemblage in Chunxiao area. Inversion resulted that the anticline trap directly overlaid on the sag. The uplift made hydrocarbon expelled from source rock and accumulated to the upper trap, this maybe the main mechanism of hydrocarbon migration. Inversion after structural subsidence, that is, Oligocene to Miocene, is the main migration and accumulation phase.