石油学报 ›› 1985, Vol. 6 ›› Issue (1): 24-30.DOI: 10.7623/syxb198501004

• 论文 • 上一篇    下一篇

垦利C50井渐新世沙河街组三段湖盆浊积岩

姚益民, 向维达, 夏玉蓉   

  1. 胜利油田地质科学研究院
  • 收稿日期:1983-09-02 出版日期:1985-01-25 发布日期:2013-07-08

NON-MARINE LACUSTRINE TURBIDITES OF THE SHAHEJIE FORMATION IN C50-WELL, KENLI, SHANDONG

Yao Yimin, Xiang Weida, Xia Yurong   

  1. The Geological Research Institute of Shengli Oilfield
  • Received:1983-09-02 Online:1985-01-25 Published:2013-07-08

摘要: 垦利C50井的53.20米岩心是一套粗碎屑岩层,属渐新世沙河街组三段早、中期。在沉积物组分、粒度、构造、生物、部分粒屑形态,及沉积速率等方面,均显示出非海相湖盆浊积岩的特征。推测,当时C50井所处的湖盆沿岸,物源丰富,水底坡度较大(约5°~10°)。因此,在山洪等强大脉冲式水动力激发下,含有大量陆缘碎屑的高密度泥沙流,沿水下斜坡呈悬浮状态,间歇性地潜向C50井所处的深湖区,形成由基本无化石粗碎屑岩、含再沉积近岸生物的细拉碎屑岩,与具深水型生物的泥岩交替出现为特征的浊积岩休。在顶底两套较细粒的末梢相层系之间,构成有利的油气储盖组合。

关键词: 浊积岩, 沙河街组三段, 渐新世, 沉积速率, 湖盆, 泥岩层, 介形虫, 碎屑岩层, 储盖组合, 化石

Abstract: 53.2 m of cores from C-well in Kenli District, being a suite of coarse clastics intercalated with thin beds of mudstone, are identified to be non-marine lacustrine turbidites of the 3rd member of the Shahejie Formation in Oligocene. The sedim eats include 4 cycles and, at least, 19 rhythmic successions grading from coarse to finer sandstones and mudstones. From their composition, granularity, structure, fossils, grain morphology and rate of deposition etc., characteristic of lacustrine turbidites, they can be geologically reconstructed as follows: The basin is believed to be surrounded by an area rich in source materials,with a steep floor dipping at about 5-10. Under these conditions, triggered by the powerful and pulsatory hydrodynamic agents as mountain torrents, the turbidity currents containing large amounts of epicontinental elastics in suspension slipped along the subaqueous slope towards the deep-water region where the C-Well is located. A turbidite mass was thus deposited, characterized with the occurrence of coarse elastics containing little fossils and fine elastics with reworked neritic organisims alternating with mudstone containing deep-water fossils. Judging from the facies sequence, it is presumed that this section is a thick intermediate layer lying between two distal series, favourable for the formation of oil and gas pools.