石油与天然气地质 ›› 2023, Vol. 44 ›› Issue (3): 637-650.doi: 10.11743/ogg20230309

• 油气地质 • 上一篇    下一篇

琼东南盆地中生代潜山成储主控因素及分布规律

侯明才1(), 何小胡2, 金秋月2, 曹海洋1, 贺礼文2, 阙有缘1, 陈安清1   

  1. 1.油气藏地质及开发工程国家重点实验室(成都理工大学),四川 成都 610059
    2.中海石油(中国)有限公司 海南分公司,海南 海口 570311
  • 收稿日期:2023-02-15 修回日期:2023-03-20 出版日期:2023-06-01 发布日期:2023-06-05
  • 通讯作者: 何小胡 E-mail:houmc@cdut.edu.cn
  • 第一作者简介:侯明才(1968—),男,教授、博士生导师,大地构造沉积学、古地理学、石油地质学。E-mail: houmc@cdut.edu.cn
  • 基金项目:
    中海石油(中国)有限公司海南分公司科技项目(CCL2021HNFN0248);海南省院士创新平台科研项目

Factors controlling the formation and distribution of Mesozoic buried hill reservoirs in the Qiongdongnan Basin

Mingcai HOU1(), Xiaohu HE2, Qiuyue JIN2, Haiyang CAO1, Liwen HE2, Youyuan QUE1, Anqing CHEN1   

  1. 1.State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Chengdu University of Technology,Chengdu,Sichuan 610059,China
    2.Hainan Branch,CNOOC,Haikou,Hainan 570311,China
  • Received:2023-02-15 Revised:2023-03-20 Online:2023-06-01 Published:2023-06-05
  • Contact: Xiaohu HE E-mail:houmc@cdut.edu.cn

摘要:

中国海域盆地潜山已成为重要的勘探新领域。琼东南盆地中生代潜山勘探钻揭多个含气构造,但未获得规模性气藏发现。究其原因,储层成因机制和分布规律是制约潜山勘探大发现的瓶颈。基于琼东南盆地已有钻井、岩心、薄片和地球物理资料,研究了琼东南不同构造带潜山储层的发育特征,并探究了潜山储层的成因机制。结果表明:①储集空间主要是构造裂缝,前新生代的印支期和燕山期逆冲挤压构造是成缝关键,相关的先存主断层为潜山分带结构形成奠定了基础,新生代拉张构造活动使先存网状断裂体系活化;②以长英质矿物为主的基岩是最有利的储集岩,多期流体作用有效改造了潜山储层质量,并促成了潜山储层的垂向分带性;③琼东南盆地中生代潜山构造带可划分为南部双层强构造改造型潜山、中部三层风化-构造改造型潜山及北部准单层弱风化改造型潜山;④经历印支期构造活动的老基岩更有利于优质潜山储层发育,邻近凹陷周缘的潜山更有利于形成大型气藏。

关键词: 构造演化, 储层特征, 基岩潜山, 中生代, 琼东南盆地

Abstract:

Buried hills are emerging as an important exploration target in the sedimentary basins offshore China. Despite the successful drilling of several gas-bearing prospects in the Mesozoic buried hills in Qiongdongnan Basin, there is a lack of research on the primary factors controlling oil and gas accumulation, and no large-scale gas reservoirs have been discovered so far. Clarifying the development characteristics and genetic mechanisms of these reservoirs is crucial for advancing buried hill exploration in this region. This paper examines the development characteristics of buried hill reservoirs across different structural belts in the Qiongdongnan Basin using existing drilling, core, thin section, and geophysical data. The results indicate that structural fractures are the primary reservoir space, with thrusting event of the pre-Cenozoic Indosinian and Yanshanian playing a key role in fracture formation. The presence of preexisting main faults provided the foundation for the formation of the buried hills and the Cenozoic extension activities reshaped the fracture systems. Bedrocks dominated by felsic minerals are the favorable reservoir rocks, with multi-stage fluid action effectively improving the quality of buried hill reservoirs and contributing to their vertical zoning. The Mesozoic buried hill structural belt of Qiongdongnan Basin can be classified into a double-layer type of buried hill intensively modified by tectonism in the south, a three-layer type of buried hill modified jointly by weathering and tectonism in the middle, and a single-layer type of buried hill weakly modified by weathering in the north. The study also shows that ancient bedrocks that experienced the Indosinian tectonic activity are more favorable for the development of high-quality buried hill reservoirs, while the buried hills near the periphery of the depression are more conducive to the formation of large gas reservoirs.

Key words: tectonic evolution, reservoir feature, bedrock buried hill, Mesozoic, Qiongdongnan Basin

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