石油与天然气地质 ›› 2019, Vol. 40 ›› Issue (5): 1056-1064.doi: 10.11743/ogg20190511

• 油气地质 • 上一篇    下一篇

莱州湾凹陷东北洼“走滑-伸展”复合断裂控藏机理及勘探启示

石文龙, 牛成民, 杨波, 王利良, 邓辉, 王航, 张德龙   

  1. 中海石油(中国)有限公司 天津分公司, 天津 300452
  • 收稿日期:2018-05-03 修回日期:2019-05-04 出版日期:2019-10-28 发布日期:2019-08-17
  • 作者简介:石文龙(1980-),男,高级工程师,石油地质。E-mail:shiwl@cnooc.com.cn。
  • 基金资助:
    国家科技重大专项(2016ZX05024-023)。

Mechanism of “strike-slip-extensional” composite faults-controlled hydrocarbon accumulation in the northeastern Laizhouwan Sag, and its enlightenment for exploration

Shi Wenlong, Niu Chengmin, Yang Bo, Wang Liliang, Deng Hui, Wang Hang, Zhang Delong   

  1. CNOOC Tianjin Company, Tianjin 300452, China
  • Received:2018-05-03 Revised:2019-05-04 Online:2019-10-28 Published:2019-08-17

摘要: 研究区位于莱州湾凹陷东北洼,郯庐走滑断裂的东支南段,受北东向走滑应力与南北向拉张构造应力共同控制。通过对“走滑-伸展”复合应力区的断裂展布特征及其构造演化进行分析,明确了KL6A区块主要受伸展应力控制,继承性伸展控圈断层和走滑压扭应力共同作用形成的断背斜是最为有利圈闭类型,位于走滑主应力带的KL6B和KL6C区块在走滑增压段发育的背斜、断背斜圈闭保存条件最为优越。依据研究结果,提出了“压扭控圈、张扭控运”走滑断裂差异控藏认识,明确了走滑主断层张扭段为油气向斜坡区运移的主要通道,较好地解决了油气是否能通过主走滑断层向斜坡区供给问题,实现了斜坡区勘探突破。此外,还建立了“油源、断层、圈闭”三元控藏模式,认为已发现的油气藏可以作为油气运移中转站向更高层位的圈闭供给油气,该认识成功实现斜坡区勘探层系的转移,在原来认为运移条件差的东营组顶部圈闭发现油气富集块,获得较大勘探发现。

关键词: 构造演化, 成藏模式, 郯庐走滑带, 莱州湾凹陷, 渤海海域

Abstract: The study area,jointly controlled by the NE-trending strike-slip stress and the NS-trending extensional tectonic stress,is located in the northeastern Laizhou Bay Sag,and the southern eastern branch of the Tanlu strike-slip fault zone.Analysis of the fault distribution and structural evolution of the composite stress zone reveals that KL6A block is mainly controlled by extensional stress;that the most favorable trap is faulted anticline formed jointly by the inherited extensional fault controlling traps and the strike-slip transpressional stress;and that the anticline and faulted anticline trap,developed at the strike-slip pressure buildup section of KL6B and KL6C blocks situated in the major strike-slip stress zone,are the most favorable areas for hydrocarbon preservation.Thereafter,we put up an innovative concept of differential reservoir-controlling effect of strike-slip faults,featuring "transpression press-controlled trap,transtension stress-controlled hydrocarbon migration".The transtentional segment of the strike-slip faults serves as the main path for oil-gas migration,making a breakthrough in the exploration of slope areas.In addition,a ternary reservoir-controlling model of "Source-Fault-Trap" is established,and it is believed that the discovered oil-gas reservoirs can act as transfer stations for further migration up to traps of even higher horizons,facilitating the exploration of slope zones.Blocks of hydrocarbon enrichment are discovered in the top traps of the Dongying Formation,which was originally considered to be poor in migration conditions,marking a major breakthrough in oil-gas exploration.

Key words: tectonic evolution, hydrocarbon accumulation model, Tanlu strike-slip zone, Laizhou Bay Sag, Bohai Sea

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