石油学报 ›› 2018, Vol. 39 ›› Issue (3): 290-303.DOI: 10.7623/syxb201803004

• 地质勘探 • 上一篇    下一篇

莺歌海盆地东方区黄流组细粒厚层重力流砂体沉积特征

黄银涛1,2, 文力1, 姚光庆2, 姜平3   

  1. 1. 湖北文理学院资源环境与旅游学院汉江研究院 湖北襄阳 441053;
    2. 中国地质大学资源学院 湖北武汉 430074;
    3. 中海石油(中国)有限公司湛江分公司 广东湛江 524057
  • 收稿日期:2017-04-14 修回日期:2017-12-09 出版日期:2018-03-25 发布日期:2018-04-10
  • 通讯作者: 姚光庆,男,1964年12月生,1985获武汉地质学院学士学位,1999年获中国地质大学(武汉)博士学位,现为中国地质大学(武汉)资源学院教授、博士生导师,主要从事储层地质学教学及相关研究工作。Email:cug218@hotmail.com
  • 作者简介:黄银涛,男,1989年1月生,2011年获长江大学学士学位,2016年获中国地质大学(武汉)博士学位,现为湖北文理学院资源环境与旅游学院讲师,主要从事沉积学教学及相关工作。Email:huangyintao@hotmail.com
  • 基金资助:

    湖北省自然科学基金项目(2014CFB636)和国家重大科技专项"南海西部海域低渗油藏勘探开发关键技术"(2016ZX05024-006)资助。

Sedimentary characteristics of thick fine-grained shallow-marine gravity flow deposits from Huangliu Formation in Dongfang area, Yinggehai Basin, China

Huang Yintao1,2, Wen Li1, Yao Guangqing2, Jiang Ping3   

  1. 1. Hanjiang Institute, Faculty of Resource Environment and Tourism, Hubei University of Arts and Science, Hubei Xiangyang 441053, China;
    2. Faculty of Earth Resources, China University of Geosciences, Hubei Wuhan 430074, China;
    3. Zhanjiang Branch, CNOOC China Limited, Guangdong Zhanjiang 524057, China
  • Received:2017-04-14 Revised:2017-12-09 Online:2018-03-25 Published:2018-04-10

摘要:

莺歌海盆地东方区中深层黄流组为浅海重力流沉积,表现为粒度细、迁移快、堆积厚的多期砂体组合。基于地震、测井、岩心及测试数据,分析了细粒厚层重力流砂体沉积特征,并探讨了浅海重力流沉积的控制因素。基于井震结合在东方区共识别出砂质碎屑流水道、浊积水道、富砂朵体和富泥朵体4种基本沉积单元。砂质碎屑流水道常位于朵体内部,均方根振幅为低值,剖面上呈U型或深V型,宽度多在1~2 km,测井单砂体厚度多大于25 m,主要发育含漂浮泥砾或泥质撕裂块状细砂岩相,取心段表现为多期反旋回特征;浊积水道剖面上表现为浅V型或蠕虫状反射,均方根振幅可为低值或高值,宽度多小于500 m,其水道末端多发育局部小型朵体,形成朵体-水道-朵体沉积样式,测井单砂体厚度多在10~25 m,主要发育递变层理和平行层理粉细砂岩相,发育不完整鲍马序列Ta—Tb段组合,取心段表现为多期正旋回特征;富砂朵体和富泥朵体表现为高连续反射,均方根振幅分别为高值和低值。研究区浅海重力流沉积受到物源供给、相对海平面变化和古地形地貌的共同控制。大规模蓝江三角洲前缘砂体是物质基础;随着海平面的上升,重力流的能量不断减弱,造成砂体发育规模减小、泥质含量增加、孔隙结构及物性变差,同时造成重力流流态的转变;陆架基底差异沉降形成的陆架低洼提供了浅海重力流沉积所需的可容纳空间,而不同的沉积样式主要受到局部古地貌的控制。

关键词: 莺歌海盆地, 东方区, 黄流组, 细粒砂体, 重力流, 沉积特征

Abstract:

The reservoir in upper Miocene Huangliu Formation of Yinggehai Basin is shallow-marine gravity flow deposits. This paper analyzed the sedimentary characteristics of channel-lobe complex(CLC) in shallow-marine environment based on 3D seismic data, well logging, core and test data. Four depositional elements have been recognized, including sandy debris-flow channel(SDFC), turbidity channel, sand-rich lobes and mud-rich lobes. The sandy debris-flow channels(SDFCs), which are characterized by low root-mean-square(RMS) amplitude on the plane and V-shaped configuration on seismic profile, are commonly located in the internal of CLC. The width of SDFC ranges from 1 km to 2 km, and the single sandbody thickness of SDFC usually exceeds 25 m. Based on the detailed core description, the SDFCs are mainly composed of massive fine-grained sandstone with mud clasts and planar fabric. The core interval from SDFC comprises multiple coarsening-upward units. The turbidity channels are characterized by low or high RMS amplitude on the plane and worm-shaped configuration on profile view. The width of turbidity channel is usually less than 0.5 km and the thickness of single sandbody is commonly less than 20 m. A small size of frontal splay is commonly developed in the front of turbidity channel, thus forming lobe-channel-lobe depositional style. The core interval from turbidity channel is mainly composed of siltstone with graded bedding and parallel bedding which indicate multiple Ta-Tb divisions of Bouma sequence. Sand-rich lobes and much-rich lobes, which show continuous sheet configuration, are characterized by high RMS amplitude and low RMS amplitude, respectively. The shallow-marine gravity flow deposits are controlled by sediment supply, relative sea-level change and paleogeomorphy induced by different subsidence of the continental shelf. The delta-front sandbody from Blue river is thought to be the main source materials. The relative sea-level change can play an important role in controlling the gravity flow deposition. The energy and erosion ability of gravity flow decrease due to the gradually rising sea level, resulting in decreasing of grain size, pore structure and physical properties and increasing of mud content of sandstone, in the meantime, the state of gravity flow transformed from sandy debris-flow to turbidity-flow because of the gradually rising sea level. What is more, the low-lying areas induced by different subsidence of the continental shelf can provide accommodation for deposits. However, the different depositional styles of CLCs are most probably related to different local paleogeomorphy.

Key words: Yinggehai Basin, Dongfang area, Huangliu Formation, fine-grained sandstone, gravity flow, sedimentary characteristics

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