Acta Petrolei Sinica ›› 2019, Vol. 40 ›› Issue (s1): 178-187.DOI: 10.7623/syxb2019S1015

• Petroleum Exploration • Previous Articles     Next Articles

Characteristics of geothermal field and the tectonic-thermal evolution in Pearl River Mouth Basin

Hu Shengbiao1,2, Long Zhulie3, Zhu Junzhang3, Hu Di1,2, Huang Yuping3, Shi Yulin3, Hu Jie1,2   

  1. 1. Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China;
    2. University of Chinese Academy of Sciences, Beijing 100049, China;
    3. Shenzhen Branch of CNOOC China Limited, Guangdong Shenzhen 518067, China
  • Received:2018-07-09 Revised:2018-12-10 Online:2019-07-25 Published:2019-07-15

珠江口盆地地温场特征及构造-热演化

胡圣标1,2, 龙祖烈3, 朱俊章3, 胡迪1,2, 黄玉平3, 史玉玲3, 胡杰1,2   

  1. 1. 中国科学院地质与地球物理研究所 北京 100029;
    2. 中国科学院大学 北京 100049;
    3. 中海石油(中国)有限公司深圳分公司 广东深圳 518067
  • 通讯作者: 胡圣标,男,1963年1月生,1985年获成都地质学院学士学位,1990年获中国科学院地质研究所地热学理学博士学位,现为中国科学院地质与地球物理研究所研究员,主要从事地热测量、盆地热史恢复及烃源岩热演化研究。Email:sbhu@mail.igcas.ac.cn
  • 作者简介:胡圣标,男,1963年1月生,1985年获成都地质学院学士学位,1990年获中国科学院地质研究所地热学理学博士学位,现为中国科学院地质与地球物理研究所研究员,主要从事地热测量、盆地热史恢复及烃源岩热演化研究。Email:sbhu@mail.igcas.ac.cn
  • 基金资助:

    国家科技重大专项(2016ZX05026-003)资助。

Abstract:

Situated on the northern margin of the South China Sea, the Pearl River Mouth Basin is a key area for off-shore hydrocarbon exploration, showing good oil and gas prospects. The characteristics of current geothermal field in Pearl River Mouth Basin was analyzed based on geothermal measurements. The Cenozoic thermal evolutionary history was reconstructed by the inversion of paleo-thermal indicators and the forward model of rift basin. Moreover, a comparative analysis was performed on the difference of tectonic-thermal evolution in the shallow and deep water areas as well as the main controlling factors. Finally, this paper summarizes the influences of different geothermal geological conditions on hydrocarbon generation and accumulation. The research results show that Pearl River Mouth Basin is a "hot basin" characterized by high geothermal gradient. The geothermal gradient presents an overall increasing trend from shallow to deep water areas, corresponding to the thinning trend of crust and lithosphere from north to south. The Pearl River Mouth Basin experienced two-phase rifting, showing an episodic increase in the basal heat flow. The Zhu I depression in shallow water area reached its maximum paleo-heat flow earlier at 33.9 Ma, but the rifting time of the basin in the deep water areas, including Baiyun sag and Liwan sag, continued until 23 Ma, followed by the post-rift thermal subsidence period, while the heat flow at the base began to decrease. The thermal history modelling of apatite fission track data (AFT) from Baiyun sag revealed that there existed a rapid increase in paleogeotemperature in the later period since 5 Ma, which may be related with the Neo-tectonic movement. Moreover, the maximum paleo-heat flow was observed in Baiyun sag on the slope is greater than other sags on continental shelf.

Key words: Pearl River Mouth Basin, geothermal field, heat flow, apatite fission track, tectonic-thermal evolution

摘要:

位于南海北缘的珠江口盆地作为中国海洋油气勘探的重点区域,具有良好的油气勘探前景。利用钻井地热测量数据分析了珠江口盆地现今地温场特征,利用古温标反演和拉张盆地模型正演相结合的方法定量揭示了盆地新生代以来的热演化史,并对比分析了浅水区和深水区构造-热演化的差异及主控因素,总结了不同地热地质条件对油气生成和富集的影响。研究结果表明,珠江口盆地具有"热盆"特征,地温梯度高。地温梯度值的总体变化趋势表现为从浅水区向深水区逐渐增高,与地壳和岩石圈向南减薄趋势一致。珠江口盆地始新世以来经历了两期裂陷拉张作用,其基底热流值表现为幕式升高的特征。浅水区珠一坳陷达到最高古热流的时间相对较早(约为33.9 Ma),而盆地深水区(白云凹陷、荔湾凹陷)裂陷拉张时间可以持续到23 Ma,随后才进入裂后热沉降期,盆地基底热流开始降低。白云凹陷磷灰石裂变径迹(AFT)热史模拟显示晚期约在5 Ma以来存在一期古地温快速增加,这可能与新构造运动有关。此外,由于深水区拉张强度大,加热时间长,陆坡区的白云凹陷最高古热流要高于陆架区的其他凹陷。

关键词: 珠江口盆地, 地温场, 热流, 磷灰石裂变径迹, 构造-热演化

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