石油学报 ›› 2017, Vol. 38 ›› Issue (1): 44-54.DOI: 10.7623/syxb201701005

• 地质勘探 • 上一篇    下一篇

准噶尔盆地东部侏罗系烃源岩和天然气地球化学特征及低熟气勘探前景

钱宇1,2, 王作栋1, 张婷1,2, 妥进才1, 王晓锋1, 王志勇3, 徐永昌1   

  1. 1. 甘肃省油气资源研究重点实验室 中国科学院油气资源研究重点实验室 甘肃兰州 730000;
    2. 中国科学院大学 北京 100049;
    3. 中国石油吐哈油田公司勘探开发研究院 新疆哈密 839009
  • 收稿日期:2016-05-01 修回日期:2016-11-10 出版日期:2017-01-25 发布日期:2017-01-23
  • 通讯作者: 王作栋,男,1966年3月生,1986年获西北师范大学理学学士学位,2009年获中国科学院兰州地质研究所博士学位,现为中国科学院油气资源研究中心高级工程师、硕士生导师,主要从事油气地球化学方面的研究。Email:wangzuo_dong@163.com
  • 作者简介:钱宇,男,1988年5月生,2012年获成都理工大学学士学位,现为中国科学院地质与地球物理研究所兰州油气资源研究中心博士研究生,主要从事油气地球化学和有机地球化学方面的研究。Email:qianyu1001@sina.com
  • 基金资助:

    中国科学院西部行动计划项目(KZCX2-XB3-12)、国家自然科学基金项目(No.41602151,No.41672127)和甘肃省重点实验室专项(1309RTSA041)资助。

Geochemical characteristic of Jurassic source rocks and natural gas in the eastern Jungar Basin and exploration potential of low-mature gas

Qian Yu1,2, Wang Zuodong1, Zhang Ting1,2, Tuo Jincai1, Wang Xiaofeng1, Wang Zhiyong3, Xu Yongchang1   

  1. 1. Key Laboratory of Petroleum Resources, Gansu Province;Key Laboratory of Petroleum Resources Research, Institute of Geology and Geophysics, Chinese Academy of Sciences, Gansu Lanzhou 730000, China;
    2. University of Chinese Academy of Sciences, Beijing 100049, China;
    3. Research Institute of Exploration and Development, PetroChina Tuha Oilfield Company, Xinjiang Hami 839009, China
  • Received:2016-05-01 Revised:2016-11-10 Online:2017-01-25 Published:2017-01-23

摘要:

对准噶尔盆地东部侏罗系烃源岩有机地球化学特征进行了研究,结果显示准噶尔盆地东部侏罗系烃源岩有机碳含量分布范围广泛,TOC为0.13%~81.06%,烃源岩评价为差-中等生油潜力,但生气潜力较大;镜质体反射率Ro分布和与热演化程度相关的生物标志化合物参数(OEP值、CPI值、甾烷和藿烷异构化参数、甲基菲指数等)表明大多数烃源岩处于未成熟-低成熟热演化阶段;有机质类型以III型为主,部分八道湾组和西山窑组烃源岩为II2型。此外,对准噶尔盆地东部侏罗系天然气组分和碳同位素组成分析结果表明,侏罗系天然气以烃类气体为主,甲烷含量为65%~98%,C1/C1-5为0.62~0.98,以湿气为主,碳同位素组成分布范围较广,其中甲烷同位素组成δ13C1值为-50.7‰~-28.2‰,乙烷δ13C2为-32.5‰~-23.7‰,丙烷δ13C3值为-30.6‰~-21.6‰,以煤型气为主,仅三台-北三台地区天然气显示为油型气-煤型气混合的特征。在对准噶尔盆地东部地区侏罗系煤系烃源岩和天然气样品分析的基础上,通过与吐哈盆地典型低熟气区烃源岩和天然气地球化学特征对比认为准噶尔盆地东部阜东和三台-北三台地区已形成一定规模的低熟气聚集,具有巨大的勘探潜力,是准噶尔盆地低熟气有望取得突破的重点地区。

关键词: 准噶尔盆地东部地区, 侏罗系, 低熟气, 煤型气, 吐哈盆地

Abstract:

Organic geochemical characteristics of Jurassic source rocks in the eastern Jungar Basin have been studied, showing that the Jurassic source rocks in the eastern Jungar Basin have a wide distribution of TOC ranging between 0.13% and 81.06% and was evaluated as having poor-moderate oil generation potential, but its gas generation potential is high. Distribution of vitrinite reflectance Ro and biomarker compound parameters associated with thermal evolution degree (OEP value, CPI value, sterane and hopane isomerization parameters, methylphenanthrene index, etc.) indicate that a majority of source rocks are situated in immature-low-mature stage of thermal evolution. Type-III organic matter is dominant in this area, though source rocks of Badaowan Formation and Xishanyao Formation partially have type II2 organic matter. In addition, analysis of elemental composition and carbon isotopic composition of Jurassic natural gas in the eastern Jungar Basin demonstrate that the Jurassic natural gas is dominated by hydrocarbon gases, in which methane content is 65%-98%, C1/C1-5 ratio is 0.62-0.98, and wet gas is predominant; carbon isotopic composition has a wide distribution, among which δ13C1 values of methane range from -50.7‰ to -28.2‰, δ13C2 values of ethane range from -32.5‰ to -23.7‰, and δ13C3 values of propane between -30.6‰ and -21.6‰, suggesting the dominant coaliferous gas, except that natural gas of Santai-Beisantai area is characterized by petroliferous gas-coaliferous gas mixture. Based on analyses of Jurassic coal measure source rock and natural gas samples from the eastern Jungar Basin area, the study area was compared with typical low-mature gas zone of the Turpan-Hami Basin in terms of geochemical characteristics of source rock and natural gas, and it is believed that a certain scale of low-mature gas accumulation has come into being in the eastern Jungar Basin, eastern Fukang sag and Santai-Beisantai area, which have huge exploration potential and thus are key areas of the Jungar Basin expected to make a breakthrough in low-mature gas exploration.

Key words: eastern Jungar Basin area, Jurassic, low-mature gas, coaliferous gas, Turpan-Hami Basin

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