石油学报 ›› 2014, Vol. 35 ›› Issue (5): 857-866.DOI: 10.7623/syxb201405005

• 地质勘探 • 上一篇    下一篇

频繁超剥地区层序、不整合特征及圈闭发育模式——以东营凹陷草桥北部地区沙河街组四段上亚段—东营组为例

张阳1, 邱隆伟1, 杨勇强1, 李际2, 师政1   

  1. 1. 中国石油大学地球科学与技术学院 山东青岛 266580;
    2. 克拉玛依红山油田有限责任公司 新疆克拉玛依 834000
  • 收稿日期:2014-01-24 修回日期:2014-04-28 出版日期:2014-09-25 发布日期:2014-08-05
  • 通讯作者: 张阳,男,1988年2月生,2010年获中国石油大学(华东)学士学位,现为中国石油大学(华东)地球科学与技术学院博士研究生,主要从事沉积层序及油气地质研究。Email:regogo@sina.com
  • 作者简介:张阳,男,1988年2月生,2010年获中国石油大学(华东)学士学位,现为中国石油大学(华东)地球科学与技术学院博士研究生,主要从事沉积层序及油气地质研究。Email:regogo@sina.com
  • 基金资助:

    国家重大科技专项(2011ZX05009-002)、国家自然科学基金石油化工联合重点基金项目(U1262203)、中央高校基本科研业务费专项资金项目(14CX06068A)资助。

Sequence and unconformity characteristics and trap development model in frequent onlap-denudation area:a case study of the Ed-Es4s in northern Caoqiao area, Dongying sag

Zhang Yang1, Qiu Longwei1, Yang Yongqiang1, Li Ji2, Shi Zheng1   

  1. 1. School of Geosciences, China University of Petroleum, Shandong Qingdao 266580, China;
    2. Karamay Hongshan Oilfield Co., Ltd., Xinjiang Karamay 834000, China
  • Received:2014-01-24 Revised:2014-04-28 Online:2014-09-25 Published:2014-08-05

摘要:

频繁超剥地区具有岩性变化快、断裂体系发育等特点,是地层油气藏形成的有利位置。为了系统研究频繁超剥地区不整合特征及圈闭发育模式,以草桥北部地区沙河街组四段(简称沙四)上亚段—东营组为例,对研究区的层序、不整合平面特征及纵向岩性配置特征、不整合对圈闭的控制作用进行了探讨,认为研究区沙四上亚段—东营组可划分为6个三级层序、16个体系域、24个准层序组。共有3个级别6个不整合,分为4种类型:削超、平超、削平以及平行不整合。一级不整合发育有不整合面之上的岩石、风化黏土层、半风化岩石3层结构,其他小级别不整合不发育风化黏土层,为2层结构。不整合对地层圈闭的控制取决于不整合平面类型与不整合纵向结构的组合关系。建立了频繁超剥地区圈闭发育模式,认为在主要发育三角洲、扇三角洲等砂体的层序中,低位域有利于形成地层超覆圈闭,高位域有利于形成不整合遮挡圈闭;在主要发育湖泊相等泥质沉积发育的层序中,低位域和湖侵域有利于形成断层-岩性圈闭和断层圈闭,高位域可形成不整合遮挡圈闭。

关键词: 层序地层格架, 不整合特征, 圈闭模式, 沙四上亚段—东营组, 频繁超剥地区

Abstract:

Frequent onlap-denudation areas are characterized by frequent stratigraphic overlap, rapid lithological change, and developed fracture systems, thus are considered to be favorable zones for formation of stratigraphic oil-gas reservoirs. This study is focused on the unconformity characteristics and trap development models in frequent onlap-denudation area by taking an example of the upper fourth sub-member of Shahejie Formation (Es4s)-Dongying Formation(Ed) in northern Caoqiao area. The sequence, horizontal unconformity characteristics and longitudinal lithological configuration characteristics, as well as unconformity control over on stratigraphic traps in the study area are investigated. The Es4s-Ed formations is divided into six third-order sequences, 16 system tracts, and 24 parasequence sets. There are six unconformities of three different levels, including four types:denudation-onlap unconformity, parallel-onlap unconformity, denudation-parallel unconformity, and parallel unconformity. The first-order unconformity has developed three layers of structures, i.e., rock above the unconformity, weathering claystone, and semi-weathered rock; and the other lower-order unconformities have developed two layers of structures without weathering claystone. The control of unconformity over the stratigraphic traps depends on the combination of plane type and longitudinal structure of the unconformity. A trap model of frequent onlap-denudation area is established, which indicates that in sequences mainly developed with sand bodies (e.g., delta and fan delta), the lowstand system tract is favorable for the formation of stratigraphic onlap traps, while the highstand system tract is favorable for the formation of unconformity block traps; in sequences mainly developed with claystone deposits (e.g., lacustrine facies), the lowstand and transgressive system tracts are favorable for the formation of fault-lithological and fault traps, while the highstand system tract is favorable for the formation of unconformity block traps.

Key words: sequence stratigraphic framework, unconformity characteristics, trap model, Es4s-Ed, frequent onlap-denudation area

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