石油与天然气地质 ›› 2008, Vol. 29 ›› Issue (4): 428-432.doi: 10.11743/ogg20080402

• 油气成藏与评价 • 上一篇    下一篇

松辽盆地深层断陷发育特征与油气富集

陈波1, 黄发木2, 夏永涛2, 罗明霞2, 刘计勇2   

  1. 1. 长江大学"油气资源与勘探技术"教育部重点实验室, 湖北, 荆州, 434023;
    2. 长江大学, 地球科学学院, 湖北, 荆州, 434023
  • 收稿日期:2008-06-20 出版日期:2008-08-24 发布日期:2012-01-16

Characteristics of development of deep fault depressions and hydrocarbon accumulation in the Songliao Basin

Chen Bo1, Huang Famu2, Xia Yongtao2, Luo Mingxia2, Liu Jiyong2   

  1. 1. Key Laboratory of Exploration Technologies for Oil and Gas Resources Yangtze University, Ministry of Education, Jinzhou, Hubei 434023, China;
    2. College of Geosciences, Yangtze University, Jingzhou, Hubei 434023, China
  • Received:2008-06-20 Online:2008-08-24 Published:2012-01-16

摘要:

松辽盆地断陷层系由70多个彼此分割、规模大小不一的断陷组成,不同的断陷发育程度与油气富集程度差异很大。通过对断陷特征及伴生火山岩的研究,发现由于晚侏罗世和早白垩世太平洋板块以不同方向、不同速度向东北亚板块的俯冲作用,松辽盆地断陷在发育阶段受不同区域构造作用的影响,造成了不同断陷发育时期和发育规模。晚侏罗世东北亚板块受太平洋板块的正向俯冲,松辽盆地区地幔上隆、地壳减薄,形成类似"三联点"的断陷分布特征。由于受构造应力传递的滞后效益的影响,在三联点附近的断陷发育早、伸展作用强、断陷规模大、断陷沉积厚,而远离三联点的断陷发育特征则相反。在早白垩世,控制断陷发育的区域构造应力场由拉张作用转变为张扭作用,且作用范围仅限于东部断陷区和古中央隆起带两侧断陷,这一区域的断陷持续的裂陷,而其他区域断陷则停止发育,从而进一步扩大不同断陷发育的不均衡性。持续发育型断陷规模大、断陷层厚、发育多套烃源岩层系,油气富集程度高,勘探潜力大;晚期发育型断陷次之,早期发育型断陷因断陷规模小、断陷层厚度薄,勘探潜力极小。

关键词: 三联点, 断陷, 火山活动, 油气富集, 松辽盆地

Abstract:

More than 70 fault depressions of various scales occur in the Songliao Basin and they have significantly different levels of development and hydrocarbon enrichment.Study of the characteristics of the fault depression and the associated volcanics shows that the subduction of the Pacific plate to the Northeast-Asia plate in different directions and speeds during the Late Jurassic and Early Cretaceous resulted in the development of fault depressions of various scales in different stages.In the Late Jurassic,the positive subduction of the Pacific plate to the Northeast-Asia plate caused the rising of the upper Mantle and the thinning of the earth crust,and resulted in the characteristics of fault depression distribution similar to "triple junction".Influenced by the hysteretic effect of tectonic stress transmission,fault depressions near the triple junction are characterized by early development, strong extension,large scale and thick deposits.In contrast,fault depressions far from the triple junction are characterized by late development,weak extension,small scale and thin deposits.In the Early Cretaceous,the regional tectonic stress field converted from extension to transtension,with its influences limited to the eastern fault depression and the fault depressions on both sides of the central uplift.The continuous development of the fault depression in this region and the stagnant of the development of fault depressions in other regions further enhanced the unbalance of development of fault depressions.The continuously developed fault depressions are characterized by large scale,thick fault depression sequences,multiple sets of source rocks,high level of hydrocarbon enrichment,and large potential of exploration.The fault depressions developed in late stage have relatively smaller exploration potential.The fault depressions developed in early stage are characterized by small scale, thin sequence and the least exploration potential.

Key words: triple junction, fault depression, volcanic activity, hydrocarbon accumulation, Songliao Basin

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