石油学报 ›› 2014, Vol. 35 ›› Issue (5): 879-889.DOI: 10.7623/syxb201405007

• 地质勘探 • 上一篇    下一篇

裂谷盆地盐构造形成演化及油气成藏地质意义——以苏丹红海裂谷盆地为例

吴珍云1, 尹宏伟1, 汪新2, 郑俊章3, 王兴元1   

  1. 1. 南京大学地球科学与工程学院 江苏南京 210046;
    2. 浙江大学地球科学系 浙江杭州 310027;
    3. 中国石油勘探开发研究院 北京 100083
  • 收稿日期:2014-04-14 修回日期:2014-07-12 出版日期:2014-09-25 发布日期:2014-08-05
  • 通讯作者: 尹宏伟,男,1971年5月生,1993年获南京大学学士学位,2003年获美国阿拉巴马大学博士学位,现为南京大学地球科学与工程学院教授,主要从事盐构造、构造地质及模拟方面的研究工作。Email:hwyin@nju.edu.cn
  • 作者简介:吴珍云,男,1986年2月生,2008年获东华理工大学学士学位,现为南京大学博士研究生,主要从事盐构造、构造地质模拟及应用地球物理方面的研究工作。Email:zyw5918@163.com
  • 基金资助:

    国家自然科学基金项目(No.40872134,No.41272227)和国家重大科技专项(2011ZX05029-002)资助。

Simulation of salt structure formation and evaluation of its geological significance to oil-gas accumulation:a case study of the Sudanese Red Sea rift basin

Wu Zhenyun1, Yin Hongwei1, Wang Xin2, Zheng Junzhang3, Wang Xingyuan1   

  1. 1. School of Earth Sciences and Engineering, Nanjing University, Jiangshu Nanjing 210046, China;
    2. Department of Earth Sciences, Zhejiang University, Zhejiang Hangzhou 310027, China;
    3. PetroChina Research Institute of Petroleum and Development, Beijing 100083, China
  • Received:2014-04-14 Revised:2014-07-12 Online:2014-09-25 Published:2014-08-05

摘要:

在裂谷盆地油气构造圈闭研究中,盐岩的沉积使得构造圈闭类型复杂多样化,同时也增加了油气勘探的难度,尤其是盐下油气勘探的难度。以苏丹红海裂谷盆地作为研究实例,利用比例化物理模拟实验探讨含盐裂谷盆地盐相关构造演化机制和影响因素,并结合研究区地震剖面和地层岩性特征讨论其对油气构造圈闭形成和油气成藏的影响。模拟实验结果表明,同裂谷沉积及基底断裂作用是影响苏丹红海盆地内盐构造演化的2个主要控制因素。同时,原始盐岩沉积厚度对盐构造演化及样式也有重要的影响。综合实验模拟结果和研究区地震剖面分析认为苏丹红海裂谷盆地盐上构造圈闭主要类型有盐构造相关的遮挡圈闭、滚动背斜圈闭和披覆构造圈闭;盐下构造圈闭主要为断背斜等基底断块相关的构造圈闭。此外,受地层岩性特征和盐岩沉积及构造分布等影响,盆地形成盐上自生自储、盐下下生上储2套油气成藏模式。对比分析显示盐上、盐下储集层性能相当,但盐下油源条件较盐上好,且存在致密的盐岩层盖层和丰富的基底断裂油气运移通道。因此,综合分析认为苏丹红海裂谷盆地盐下断块油气成藏具有巨大的潜力,可以作为未来油气勘探的重点领域。

关键词: 苏丹红海, 裂谷盆地, 物理模拟, 盐构造, 同构造沉积, 基底断裂, 构造圈闭, 油气成藏

Abstract:

In rift basins, salt rock deposition leads to the formation of complex and diverse types of oil- and gas-bearing structural traps, greatly increasing the difficulty in oil and gas exploration, especially in subsalt strata. Taking as an example the Sudanese Red Sea rift basin, this study explored the evolutionary mechanism and influencing factors of salt-related structures in rift basins through scaled physical modeling. Combined with seismic profiles and stratigraphic lithology, this paper discussed the significance of salt-related structures to the formation of oil-and gas-bearing structural traps and associated hydrocarbon accumulation. The results from physical modeling indicate that syn-tectonic deposition and basement faulting are two major factors influencing the evolution of salt-related structures in the Sudanese Red Sea rift basin. Additionally, the initial thickness of salt rocks has a significant impact on the evolution of salt-related structures. Combined with the interpretation of seismic profiles, it is considered that in the Sudanese Red Sea rift basin include, the major types of supra-salt structural traps include salt-related barrier trap, rolling anticline trap and drape fold trap, whereas the sub-salt structural traps mainly include basement-fault-block-related structural traps such as fault-related anticlines. Due to the influence of stratigraphic lithology, salt rock deposition and salt structure distribution, two oil-and-gas-accumulation systems are developed in the rift basin: the self-generating and self-preserving reservoir in the supra-salt strata, and the lower-generating and upper-preserving reservoir in the subsalt strata. Comparison analysis shows that the supra- and sub-salt reservoirs have comparable properties. However, the sub-salt reservoir has better hydrocarbon source rocks, which contains a dense salt rock cover and abundant pathways for hydrocarbon migration through the basement faults. Hence, it is believed that the sub-salt basement fault blocks have huge potential for oil and gas accumulation and provide an important area for future oil and gas exploration in the Sudanese Red Sea rift basin.

Key words: Sudanese Red Sea, rift basin, physical modeling, salt-related structure, syn-rift deposition, basement faults, structural trap, oil-gas accumulation

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