王古1井奥陶系油气成因及其意义  

Origin and Significance of the Ordovician Oil from Well WG 1,Dongying Depression, Bohai Bay Basin

作　　者：李素梅[1] 庞雄奇[1] 邱桂强[2] 高永进[2] 

机构地区：[1]中国石油大学油气成藏机理教育部重点实验室 [2]中国石化胜利石油有限公司,山东东营257015

出　　处：《地球科学（中国地质大学学报）》2005年第4期451-458,479,共9页Earth Science-Journal of China University of Geosciences

基　　金：国家重点基础研究发展规划项目(No.G199943310).

摘　　要：首次在东营凹陷南斜坡王古1井奥陶系古潜山中获得深层高蜡油(含蜡量40.84%),其富含蜡质烃,甾、萜类等高分子量化合物含量甚微.采用分子筛络合技术对王古1井原油中的甾、萜类化合物进行了浓缩,并对碳酸盐岩储层中的方解石脉包裹体进行了化学成分分析.结果表明,王古1井奥陶系原油及储层包裹烃的组成与分布具有深层孔店组烃源岩的特征,与沙四段烃源岩相关性差,揭示奥陶系原油不同于以往发现的第三系沙河街组原油.正构烷烃单体同位素δ13C值分析也表明,王古1井原油与孔店组烃源岩接近且变化趋势大体一致,反映孔店组为其可能的油源岩.王古1井奥陶系油气的发现表明东营凹陷存在一套迄今尚未发现的深层油源岩,该区具有深层油气勘探潜力.Considerable quantities of Ordovician oils were recently discovered from the burial hill in well WG 1 in the south slope of the Dongying depression, Bohai Bay basin. The oils are characterized by high content of waxy alkanes (40.84%) with a low concentration of steranes and terpanes, which are completely different from the overlying Tertiary oils of the Shahejie Formation. By removing the alkanes from the Ordovician oil with a molecular sieve and analyzing the inclusion component of well WG 1, important biomarker information was obtained, such as steranes and terpanes, which are crucial for source rock tracing. Results show that the Ordovician oil and inclusion component of the well WG 1 correlated well with the source rocks of the Tertiary Kongdian Formation (Ek2) rather than that of the Shahejie Formation, suggesting potential source rocks for the Ordovician oils. Results of the δ13C values of the compound-specific isotope of alkanes show similar values and varying trend of the Ordovician oils to that of the Ek2 source rocks, which further proves the Ek2 mudstones to be responsible for the deep oils. The discovery of the high waxy oils of Ordovician from well WG 1 suggests the existence of a new set of deep source rocks and good potential of deep oils in the Dongying depression.

关 键 词：奥陶系 古潜山 高蜡油 源岩 孔店组 

分 类 号：P618.13[天文地球—矿床学]