石油学报 ›› 2019, Vol. 40 ›› Issue (6): 635-645.DOI: 10.7623/syxb201906001

• 地质勘探 •    下一篇

渤海湾盆地新生界沉积洼陷类型及与油气富集的关系

蒋有录1, 苏圣民1, 刘华1, 王永诗2, 刘景东1   

  1. 1. 中国石油大学(华东)地球科学与技术学院 山东青岛 266580;
    2. 中国石油化工股份有限公司胜利油田分公司 山东东营 257001
  • 收稿日期:2018-08-29 修回日期:2019-01-18 出版日期:2019-06-25 发布日期:2019-07-02
  • 通讯作者: 蒋有录,男,1959年10月生,1982年获华东石油学院石油地质专业学士学位,1999年获石油大学(北京)博士学位,现为中国石油大学(华东)地球科学与技术学院教授、博士生导师,主要从事油气藏形成与分布规律方面的研究。Email:jiangyl@upc.edu.cn
  • 作者简介:蒋有录,男,1959年10月生,1982年获华东石油学院石油地质专业学士学位,1999年获石油大学(北京)博士学位,现为中国石油大学(华东)地球科学与技术学院教授、博士生导师,主要从事油气藏形成与分布规律方面的研究。Email:jiangyl@upc.edu.cn
  • 基金资助:

    国家科技重大专项(2016ZX05006-003)资助。

Types of Cenozoic sedimentary subsags and their relationship with hydrocarbon enrichment in Bohai Bay Basin

Jiang Youlu1, Su Shengmin1, Liu Hua1, Wang Yongshi2, Liu Jingdong1   

  1. 1. School of Geosciences, China University of Petroleum, Shandong Qingdao 266580, China;
    2. Sinopec Shengli Oilfield Company, Shandong Dongying 257001, China
  • Received:2018-08-29 Revised:2019-01-18 Online:2019-06-25 Published:2019-07-02

摘要:

渤海湾盆地发育数十个含油气凹陷,各凹陷往往发育多个新生界沉积厚度大、地层发育较完整的洼陷。沉积洼陷是凹陷中油气生成、运聚的基本单元,并控制了油气的平面分布;不同类型洼陷的沉降和沉积特征以及油气富集情况存在较大的差异。基于大量统计资料,对渤海湾盆地新生界的洼陷类型及与油气富集的关系开展了分析。渤海湾盆地新生界洼陷依据控洼断层的活动速率以及地层的沉积速率、埋藏史和剥蚀厚度,可划分为早期发育型、继承发育型和晚期发育型3大类,并可细分为早期Ⅰ型、早期Ⅱ型、继承Ⅰ型、继承Ⅱ型、晚期Ⅰ型和晚期Ⅱ型6种基本类型;不同类型洼陷的分布具有分区性,其主力烃源岩系及生烃期不同。采用模糊数学评价方法对渤海湾盆地主要含油气凹陷中的54个洼陷进行生烃能力评价,可将其划分为A类、B类、C类和D类4类生烃洼陷。沉积洼陷的发育类型与生烃类型整体上具有一定对应关系:A类和B类洼陷的生烃能力强,多为继承发育型和晚期发育型洼陷;C类和D类洼陷的生烃能力为中等-较差,以早期发育型洼陷居多。富油凹陷主要由继承发育和晚期发育的A类和B类生烃洼陷组成;而由早期发育型洼陷组成的凹陷,其含油气情况则较差。洼陷的发育类型与油气的运移距离及富集层系也具有一定相关性:继承发育和晚期发育的A类生烃洼陷的供烃动力强,油气运移距离较长,因此,继承发育型洼陷中油气多富集于中部层系,而在晚期发育型洼陷中油气在浅部层系较富集;早期发育型洼陷的供烃动力较弱,油气运移的距离较短且油气主要赋存于下部层系。

关键词: 沉积洼陷, 富油凹陷, 生烃洼陷, 油气富集, 渤海湾盆地

Abstract:

There are dozens of oil-bearing sags in Bohai Bay Basin, where multiple Cenozoic subsags with large sedimentary thickness and complete stratigraphic system are developed in each sag. Sedimentary subsag is the basic unit of oil and gas generation, migration and accumulation in the sag, controlling the plane distribution of oil and gas. There are great differences in the sedimentation and sedimentary characteristics of different types of subsags and hydrocarbon enrichment. Based on massive statistical data, this study analyzes the Cenozoic subsag types of Bohai Bay Basin and their relationships with oil and gas enrichment. The Cenozoic subsags in Bohai Bay Basin can be classified into early developmental, inherited developmental and late developmental types according to the activity rates of subsag-controlling faults and the sedimentary rates, burial history and denudation thickness of strata, which can be subdivided into 6 basic types of early type Ⅰ, early type Ⅱ, inherited type Ⅰ, inherited type Ⅱ, late type Ⅰ and late type Ⅱ. Various types of subsags are characterized with zonal distribution, different chief source rock series and hydrocarbon-generating periods. The fuzzy mathematics evaluation method was used to evaluate the hydrocarbon generation potentials of 54 subsags in the main sags of Bohai Bay Basin; they can be classified into 4 categories of hydrocarbon-generating subsags, namely category A, B, C and D. The developmental types of sedimentary subsag have certain corresponding relationships with the hydrocarbon-generating categories, i.e., category A and B subsags have strong hydrocarbon generation potentials, dominated by the inherited and late developmental subsags; category C and D subsags have moderate-poor hydrocarbon generation potentials, dominated by the early developmental subsags. The oil-rich sags are mainly composed of the inherited and late developmental, category A and B hydrocarbon-generating subsags, while the sags composed of the early developmental subsags have low hydrocarbon contents. The developmental types of subsags also have certain relations to the hydrocarbon migration distances and the enrichment strata:the category A hydrocarbon-bearing subsags with inherited and late developmental features have strong hydrocarbon supply capacities and long hydrocarbon migration distances. Therefore, for the inherited developmental subsags, oil and gas are enriched in the middle strata, while for the late developmental subsags, oil and gas can be enriched in the shallow strata; the early developmental subsags have weak hydrocarbon supplies and short hydrocarbon migration distances so that oil and gas mainly occur in the deep strata.

Key words: sedimentary subsag, oil-rich sag, hydrocarbon-generating subsag, hydrocarbon enrichment, Bohai Bay Basin

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