石油与天然气地质 ›› 2019, Vol. 40 ›› Issue (2): 413-422.doi: 10.11743/ogg20190219

• 油气地质 • 上一篇    下一篇

松辽盆地伏龙泉断陷边界断层构造反转率

张美华, 王春华, 栾颖   

  1. 中国石化 东北油气分公司, 吉林 长春 130062
  • 收稿日期:2018-03-12 修回日期:2018-12-04 出版日期:2019-04-28 发布日期:2019-01-23
  • 作者简介:张美华(1982-),男,工程师,石油地质。E-mail:zhangmeiyin@foxmail.com。
  • 基金资助:
    中国石化集团公司科技部项目(P15116)。

Inverted rate of boundary faults along Fulongquan fault depression, Songliao Basin

Zhang Meihua, Wang Chunhua, Luan Ying   

  1. Northeast Oil and Gas Branch Company, SINOPEC, Changchun, Jilin 130062, China
  • Received:2018-03-12 Revised:2018-12-04 Online:2019-04-28 Published:2019-01-23

摘要: 盆地边界断层通常为同沉积断层,同沉积断层活动时间相对短且具有间歇性,地层沉积时间相对较长,这决定了断陷盆地的地层分布格局。通过分析同沉积断层理论模式,认为断陷缓坡带地层厚度与边界断层下盘厚度相当,边界断层下盘通常缺失与上盘对应的地层,可选择断陷盆地缓坡带地层厚度代替边界断层下盘厚度,建立虚拟下盘厚度格架,然后运用位移-距离曲线等方法对边界断层开展定量研究。伏龙泉断陷位于松辽盆地东南部,为东断西超的半地堑盆地,发育4条边界断层,依次控制了4个沉积次洼,4条边界断层的活动强度和反转程度存在差异。伏龙泉断陷经历了断陷期、拗陷期、反转期三个主要的构造期次,分别对应于边界断层强烈活动、停止活动、反转活动3个演化阶段,发生于白垩纪末的反转活动使得边界断层再次活化,形成油气运移通道,深层油气向上运移到浅层圈闭中,形成次生油气藏。通过定量计算伏龙泉断陷各边界断层的反转率,结合油气富集规律认识,认为反转率适中的区域最有利于次生油气藏的形成和保存。

关键词: 构造反转, 位移-距离曲线, 反转率, 同沉积断层, 边界断层, 松辽盆地

Abstract: The boundary faults of basin are generally synsedimentary faults,which are characterized as having relatively short period of activity with intermittency and relatively long stratum deposition.The two factors together determine the stratigraphic distribution of fault depression basins.This paper analyzed the theoretical model of synsedimentary faults.Results show that the thickness of the gentle slope zones of the fault depression is equivalent to that of the footwall of the boundary fault,and at the footwall,the strata corresponding to the upper wall are usually absent.The thickness of strata in the gentle slope zone can replace that of the footwall of the boundary fault,and a virtual footwall thickness framework can be established,then the boundary faults can be studied quantitatively by means of displacement-distance graphs.Fulongquan fault depression locating in the southeast of Songliao Basin,a half-graben basin with faulting in the east and overlapping in the west,develops four boundary faults controlling four sub-sags in turn,and the activity intensity and inversion degree of these boundary faults are different.It has experienced three main structural movement,fault depression,depression,and inversion,corresponding to the three active phases of boundary faults,intense activity,inactivity,and inverting activity.The structural inverdion wich happened in the end of the Cretaceous,functions to reactivate the boundary faults and form hydrocarbon migration paths;hence the deep hydrocarbons migrated upward to the shallower traps,and the secondary hydrocarbon reserviors are thus produced.The quantitarive study about the inverted rate of each bondary fault,combined with the study of hydrocarbon accumulation patterns in Fulongquan fault depression,indicates that the areas with mrdium inverted rate are the most conducive in the generation and preservation of secondary hydrocarbon reservoirs.

Key words: structural inversion, displacement-distance graph, inverted rate, synsedimentary fault, boundary fault, Songliao Basin

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