石油与天然气地质 ›› 2020, Vol. 41 ›› Issue (5): 891-902.doi: 10.11743/ogg20200501

• 油气地质 • 上一篇    下一篇

渤海海域渤中凹陷渤中19-6深层潜山凝析气藏的充注成藏过程

薛永安1(), 王奇2, 牛成民1, 苗全芸3, 刘梦醒2, 殷杰4   

  1. 1. 中海石油(中国)有限公司 天津分公司, 天津 300459
    2. 中国石油大学(华东), 山东 青岛 266580
    3. 中国石油大学(北京), 北京 102249
    4. 长江大学, 湖北 武汉 430100
  • 收稿日期:2020-05-05 出版日期:2020-10-28 发布日期:2020-10-22
  • 作者简介:薛永安(1963-),男,博士,教授级高级工程师,海上油气勘探与管理。E-mail:xueya@cnooc.com.cn
  • 基金资助:
    国家科技重大专项(2016ZX05024-003-008);国家自然科学基金项目(41821002)

Hydrocarbon charging and accumulation of BZ 19-6 gas condensate field in deep buried hills of Bozhong Depression, Bohai Sea

Yong'an Xue1(), Qi Wang2, Chengmin Niu1, Quanyun Miao3, Mengxing Liu2, Jie Yin4   

  1. 1. Tianjin Branch of CNOOC, Tianjin 300459, China
    2. China University of Petroleum(East China), Qingdao, Shandong 266580, China
    3. China University of Petroleum(Beijing), Beijing 102249, China
    4. Yangtze University, Wuhan, Hubei 430100, China
  • Received:2020-05-05 Online:2020-10-28 Published:2020-10-22

摘要:

综合凝析油的地球化学特征、周缘洼槽烃源岩生烃史、流体包裹体岩相学观察、均一化温度及含油包裹体的石英颗粒的频数(GOI),分析了渤中19-6地区深层凝析气的来源及充注成藏过程。研究表明:潜山凝析油气的热成熟度高,对应的烃源岩Ro约1.3%。轻烃、碳同位素组成与生物标志物参数分析表明凝析油气来源于油型母质,即沙河街组烃源岩。烃类包裹体主要分布于石英微裂隙,少量分布于加大边。液态烃类包裹体呈黄绿色及蓝白色荧光,GOI值高达80%,揭示高的原油充满度。渤中19-6深层潜山凝析气藏表现为近源、早油晚气连续充注,其中原油充注在明化镇组下段时期(12~5.1 Ma),天然气大量充注时间为明化镇组下段沉积末期甚至更晚的时期(5.1~0 Ma)。尽管新构造运动期油气垂向调整显著,但烃源岩快速熟化与近源强充注是构造活化区深层潜山动态富集的重要物质基础。

关键词: 凝析油气来源, 油气充注历史, 渤中19-6潜山, 渤海海域, 渤海湾盆地

Abstract:

The sources' charging and possible accumulation processes of hydrocarbon in the BZ 19-6 buried hill reservoirs were investigated based on analyses of the geochemistry of condensate samples, the hydrocarbon generation history of source rocks in neighboring sags, and the petrology, homogenization temperature and GOI values (frequency of quartz grains containing oil-bearing inclusions) of fluid inclusions.The results reveal that the gas condensate in the BZ 19-6 reservoirs is high in thermal maturity and its corresponding source rocks have Ro values approximately 1.3%.The light hydrocarbon and carbon isotopic compositions as well as biomarkers all point to oil-prone source rocks in the Shahejie Formation (Es3 and Es1).Most hydrocarbon inclusions are distributed in the micro-cracks of quartz, with only a few scattering at the overgrown edge.Liquid hydrocarbon inclusions have yellow-green and blue-white fluorescent, with a GOI value of up to 80%, indicating an almost fully-charged reservoir.The gas condensate reservoirs in the Bozhong Sag are characterized by nearby source rocks with continuous charging of early oil and late gas.The oil charging concentrated during the deposition of the Lower Minghuazhen Formation (12-5.1 Ma), and the large-scale gas charging occurred in the late stage of the Lower Minghuazhen Formation or even later (5.1-0 Ma).Despite an obvious vertical migration of oil and gas during the Neotectonic Movement, the rapid maturation of source rocks and strong near-source charging are considered to be a more important physical foundation for the dynamic hydrocarbon enrichment in deep buried hills of activation zones.

Key words: source of condensate oil and gas, charging history, BZ 19-6 buried hill, Bohai Sea, Bohai Bay Basin

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