石油与天然气地质 ›› 2010, Vol. 31 ›› Issue (5): 583-593.doi: 10.11743/ogg20100508

• 石油与天然气地质 • 上一篇    下一篇

渤海湾盆地东营凹陷广利地区沙四上亚段物源体系及其对沉积的控制作用

  

  1. 中国科学院广州地球化学研究所,广东广州510640
  • 出版日期:2010-10-28 发布日期:2010-12-10
  • 作者简介:孙海宁(1968—),女,高级工程师,油气田开发地质。
  • 基金资助:

    教育部新世纪优秀人才支持计划项目(NCET-06-0604);国家油气重大专项(2008ZX05051-002);国家自然科学基金项目(40972080)。

Provenance system s and their control on the sedim entation of the upper Es 4 in Guangli area of the Dongying Sag,the Bohai Bay Basin

  • Online:2010-10-28 Published:2010-12-10

摘要:

岩石组分、元素地球化学以及砂砾岩百分含量等分析表明,渤海湾盆地东营凹陷广利地区沙河街组四段上亚段沉积时期存在南部和东北部两大物源体系,它们控制了广利地区沙四上亚段沉积时期的砂体成因类型与分布。沙四上亚段沉积早期以南部物源体系为主,主要发育曲流河三角洲-滨浅湖滩坝沉积体系;沙四上亚段沉积晚期以东北部物源体系为主,主要发育辫状河三角洲、扇三角洲等沉积体系;沙四上亚段沉积中期为两大物源体系的转换时期,南部和东北部物源体系共存,发育了重力流、牵引流交互沉积的多成因类型砂体。区内三角洲前缘由沿岸流改造形成的滩坝砂体是今后勘探的重点,应加大滩坝砂类岩性和构造共同控制的复合油气藏的部署和勘探。

关键词: 沙河街组, 物源体系, 沉积体系, 广利地区, 东营凹陷, 渤海湾盆地

Abstract:

According to analyses of rock component,element geochem istry and sandy net-to-gross ratio,two provenance systems,namely the southern one and the northeastern one,are believed to exist during the sedimentaˉtion of the upper4 th member ofEocene Shahejie Formation(Es 4 )in Guangli area ofDongying Sag,the BohaiBay Basin and they controlled the genetic types and distribution of sandbodies.In the early period of the sedimentation of the upperEs 4 ,the south provenance predom inated,and there developed meander river delta and shallow lake-beach bars.While in the late period the sedimentation of the upperEs 4 ,the northeast provenance predom inated,and there developed braided river delta and fan delta.In the m iddle period of the sedimentation of the upperEs 4 ,the two provenance systems coexisted,and there developed sandbodies ofmultiple genetic typeswith alternating gravity flow deposits and traction currentdeposits.Beach bars resulted from modification of longshore current at the delta front should be important targets for further exploration.Exploration of lithologic structural combination traps of beach bars types should be strengthened.

Key words: Shehejie Formation, provenance system, sedimentary system, Guangli area, Dongying Sag, BohaiBay Basin