石油与天然气地质 ›› 2022, Vol. 43 ›› Issue (6): 1445-1458.doi: 10.11743/ogg20220613

• 油气地质 • 上一篇    

银额盆地巴北凹陷烃源岩地球化学特征与资源潜力

高怡文1(), 郝世彦1(), 王庆2, 王维波1, 江绍静1, 范庆雄3, 陈治军1, 周晔1   

  1. 1.陕西延长石油(集团)有限责任公司 研究院,陕西 西安 710075
    2.中国石油 长庆油田分公司 第六采气厂,陕西 西安 710018
    3.陕西延长石油钻井工程有限公司,陕西 延安 716000
  • 收稿日期:2022-04-06 修回日期:2022-09-10 出版日期:2022-12-01 发布日期:2022-11-21
  • 通讯作者: 郝世彦 E-mail:32952030@qq.com;463632928@qq.com
  • 第一作者简介:高怡文(1982—),女,博士、高级工程师,油气地质与采收率。E-mail: 32952030@qq.com
  • 基金项目:
    自然资源部重点项目(2017YQZYPJ01);延长石油集团科技攻关项目(ycsy2020jcyj-B-03)

Geochemical characteristics and hydrocarbon resources potential of source rocks in Babei Sag, Yingen-Ejinaqi Basin

Yiwen Gao1(), Shiyan Hao1(), Qing Wang2, Weibo Wang1, Shaojing Jiang1, Qingxiong Fan3, Zhijun Chen1, Ye Zhou1   

  1. 1.Reseach Institute,Yanchang Petroleum (Group) Co. Ltd. ,Xi’an,Shaanxi 710075,China
    2.No. 6 Gas Production Plant,Changqing Oil Field Company,PetroChina,Xi'an,Shaanxi 710018
    3.Drilling Engineering Company,Yanchang Petroleum (Group) Co. Ltd. ,Yan'an,Shaanxi 716000,China
  • Received:2022-04-06 Revised:2022-09-10 Online:2022-12-01 Published:2022-11-21
  • Contact: Shiyan Hao E-mail:32952030@qq.com;463632928@qq.com

摘要:

为明确银额盆地巴北凹陷烃源岩条件和油气资源潜力,基于研究区2口探井、1 143个泥岩样品的岩石热解和38个泥岩样品的系统测试分析资料,开展烃源岩地球化学特征研究,预测有效烃源岩的分布,分析研究区的油气资源潜力,以期为该区的勘探决策和勘探部署提供依据。结果表明:①研究区潜在烃源岩为发育于银根组(K1y)、苏红图组(K1s)、巴音戈壁组三段(K1b3)、巴音戈壁组二段(K1b2)、巴音戈壁组一段(K1b1)和石炭系-二叠系(C-P)的泥岩,其中以K1b3,K1b2,K1b1和C-P的有机质丰度为最高,有机质类型以Ⅱ2-Ⅲ型为主,且高有机质丰度层段的烃源岩均达到了成熟-过成熟热演化阶段。②在有机质来源方面,高等植物对于各层段烃源岩具有较大的生源贡献。在沉积环境方面,各层段烃源岩均主要形成于弱还原-弱氧化的微咸水环境。③厘定了研究区有效烃源岩的总有机碳含量(TOC)下限值为0.80 %,成熟生烃门限深度为1 100 m,有效烃源岩主要发育于K1b3,K1b2,K1b1和C-P,其厚度在南、北两个次凹的沉积中心均较大。较好的烃源岩条件,加上活跃的油气显示,预示着研究区具有较好的油气资源潜力。

关键词: 地球化学特征, 烃源岩, 资源潜力, 巴北凹陷, 银额盆地

Abstract:

The source rocks and reservoirs in the Babei Sag, Yingen-Ejinaqi Basin, are assessed for geochemical characterization, effective source rock mapping and hydrocarbon potential analysis based on data from rock pyrolysis experiments of 1 143 mudstone samples and systematic tests of 38 mudstone samples from two local wells. The results show that potential source rocks are developed in mudstones of the Yingen Formation (K1y), Suhongtu Formation (K1s), the third, second and first members of the Bayingob Formation (K1b3, K1b2 and K1b1), and Carboniferous-Permian (C-P) systems in the sag. Among them, the latter four (K1b3, K1b2, K1b1 and C-P) have higher organic matter abundance with type Ⅱ2-typeⅢ kerogen of maturity and over-maturity. Higher plant made significant contribution to the organic carbon content in the source rocks and a weak reducing—weak oxidizing environment together with brackish water provided a setting for the source rocks to deposit. The source rocks in the sag are deemed effective when their TOC is no less than 0.80 % and threshold depth for hydrocarbon generation is 1 100 m. Based on these criteria, effective source rocks in the sag are mainly developed in K1b3, K1b2, K1b1 and C-P and have the largest thickness in two sedimentary centers (northern subsag and southern subsag). Good source rock conditions and active hydrocarbon shows indicate that the study area has good hydrocarbon exploration potential.

Key words: geochemical characteristics, source rock, petroleum resource potential, Babei sag, Yingen-Ejinaqi Basin

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