应用生烃动力学方法研究渤海湾盆地埕岛油田成藏地质时期

INVESTIGATION ON THE POOL-FORMING TIME OF THE CHENGDAO OILFIELD IN THE BOHAIWAN BASIN USING THE HYDROCARBON GENERATION KINETICS METHOD

陈永红 鹿洪友 曾庆辉 肖贤明 TANG Yong-chun

CHEN Yong-hong LU Hong-you ZENG Qing-hui XIAO Xian-ming TANG Yong-chun

中国科学院, 广州地球化学研究所, 有机地球化学国家重点实验室, 广东, 广州, 510640 2. 中国科学院, 研究生院, 北京, 100039 3. 加州理工学院, 环境与能源研究中心, 加利福尼亚, 巴萨迪那, CA61, 769

State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, ChineseAcademy of Sciences, Guangzhou, Guangdong 510640, China 2. Graduate School Chinese Academy China 3. Californian Institute of Technology, Pasadena, California CA61769, USA

渤海湾盆地埕岛油田油气成因与成藏较复杂,对成藏期次与时间一直存在疑问.本研究应用多冷阱热解气相色谱仪及相匹配的Kinetics软件,研究了该盆地典型Es3与Ed2暗色泥岩生烃动力学参数,并在此基础上对该油田油源区埕北凹陷与沙南凹陷生油岩生烃史进行了模拟计算.结果表明,埕北凹陷Es3生油岩主体在5Ma后才开始明显生烃,目前C13+转化率已达0.65左右;沙南凹陷Es3生油岩生烃作用发生在2Ma以后,现今C13+转化率在0.24左右,这2个凹陷Ed2生油岩尚处在未成熟阶段.埕岛油田主体存在2个有效的油气聚集系统:潜山—东营组下段与东营组上段—明化镇组.结合这2套油气聚集系统地质与地化特征,研究认为:下部潜山—东营组下段油气聚集系统油气主要来源于埕北凹陷Es3生油岩早期生成的油气,上部东营组上段—明化镇组油气聚集系统油气来源于埕北凹陷Es3生油岩在较高成熟阶段生成的油气.沙南凹陷Es3生油岩可能对斜坡带潜山油气藏有一定贡献.

The Chengdao oilfield of the Bohaiwan Basin is characterised by complicated petroleum infilling history. Up to now, there still remain some problems to be solved. In this paper, the multi-cool traps GC, a patented instrument from the Californian Institute of Technology, is used, combined with related Kinetics software, to investigate hydrocarbon generation kinetics parameters of 2 typical source rocks from the southern part of Bozhong Depression. Based on this, petroleum generation history of source rocks from the Chengbei Depression and Sha'nan Depression is modeled with Kinetics software. The results have shown that, the Es3 source rocks from Chengbei Depression entered into oil window about 5 Ma ago, and the present conversion of hydrocarbons C13+ has reached 0.65. The Es3 source rocks from Sha'nan Depression have lower maturation level, with petroleum generation occurring 2 Ma ago, and the present C13+ conversion has reached 0.24. However, the Ed2 source rocks from these 2 depressions have not become mature. The Chengdao oilfield can be subdivided into 2 petroleum accumulation systems: the lower system of buried hill-lower Dongying Formation and the upper system of upper Dongying Formation-Minghuazhen Formation. Combined with petroleum geology and geochemistry of the petroleum accumulation systems, it is belived that, the lower accumulation system is mainly related to the earlier formed petroleum from the Es3 source rocks from Chengbei Depression, and petroleum in the upper accumulation system originated from the later stage petroleum generation of the Es3 source rocks from Chengbei Depression. The Es3 source rocks from Sha'nan Depression possibly have contribution to the lower accumulation system near slope area.

国家自然科学基金(40072043).

https://doi.org/10.11781/sysydz200406580