东海西湖凹陷中央背斜带油气成藏模式研究

文章利用包裹体测温和成岩矿物伊利石测年数据资料，对东海盆地西湖凹陷中央背斜油气运移及成藏的基本模式进行了研究，认为中央背斜带储层流体包裹体明显分为盐水包裹体和有机包裹体，包裹体均一化温度分为3期，其对应的地质时间分别为中中新世、中新世晚期和上新世至第四纪。储层自生伊利石同位素地质年龄自北向南分别为23.5~26.5 Ma、18.31~21.86 Ma、12.58~13.63 Ma，表明北部油气成藏时间早于中南部。综合分析认为中央背斜带发生过早、中、晚3期油气运移和聚集活动，以晚期最为重要，其幕式特征明显。成藏期总体时间长，多期成烃、多次充注，同期不同源是中央背斜带油气成藏的基本模式。

HYDROCARBON ACCUMULATION MODE IN THE CENTRAL ANTICLINAL ZONE OF XIHU DEPRESSION, DONGHAI BASIN

The hydrocarbon migration and accumulation mode in the central anticlinal zone of Xihu depression, Donghai Basin is investigated by means of inclusion thermometry and authigenic illite dating data. The fluid inclusions in the central anticlinal zone reservoir can be divided into salt water inclusion and organic inclusion. The homogenization temperatures of the inclusion can be divided into 3 stages and their relevant geologic periods are Middle Miocene, Later Miocene and Pliocene—Quaternary respectively . The isotopic ages of authigenic illite in the reservoir are 23.5—26.5 Ma, 18.31—21.86 Ma and 12.58—13.63 Ma from north to south, which shows the time of hydrocarbon accumulation of northern part is earlier than middle and southern parts. They are considered that early, middle and late 3 hydrocarbon migration and accumulation processes were happened in the central anticlinal zone and the therminal is primary and multiple hydrocarbon generation, multiple migration, multiple accumulation and multiple source rocks are the fundamental of oil gas accumulation mode in the zone.