Acta Petrolei Sinica ›› 2016, Vol. 37 ›› Issue (9): 1090-1101.DOI: 10.7623/syxb201609003

• Petroleum Exploration • Previous Articles     Next Articles

Sedimentary characteristics of alluvial-fluvial systems and forming conditions of lithologic reservoirs in the large slope area: a case study of Neogene Shawan Formation in Chunguang block, Junggar Basin

Chen Xuan1, Yang Zhenfeng2, Wang Zhenqi1, Yue Xinxin2, Liu Huan2, Zhang Chengzhuang2, Wang Yaning1   

  1. 1. Key Laboratory of Exploration Technologies for Oil and Gas Resources, Ministry of Education, Yangtze University, Hubei Wuhan 430100, China;
    2. Geophysical Prospecting Institute, Sinopec Henan Oilfield Company, Henan Zhengzhou 450016, China
  • Received:2016-02-24 Revised:2016-07-06 Online:2016-09-25 Published:2016-09-30

大型斜坡区冲积-河流体系沉积特征与岩性油气藏形成条件——以准噶尔盆地春光区块沙湾组为例

陈轩1, 杨振峰2, 王振奇1, 岳欣欣2, 刘焕2, 张成壮2, 王雅宁1   

  1. 1. 长江大学油气资源与勘探技术教育部重点实验室 湖北武汉 430100;
    2. 中国石油化工股份有限公司河南油田分公司石油物探技术研究院 河南郑州 450016
  • 通讯作者: 陈轩,男,1983年6月生,2005年毕业于长江大学资源勘查工程专业,2011年获中国石油勘探开发研究院博士学位,现为长江大学副教授,主要从事沉积储层和油气田勘探相关的研究和教学工作。Email:chenxuanwolf@163.com
  • 作者简介:陈轩,男,1983年6月生,2005年毕业于长江大学资源勘查工程专业,2011年获中国石油勘探开发研究院博士学位,现为长江大学副教授,主要从事沉积储层和油气田勘探相关的研究和教学工作。Email:chenxuanwolf@163.com
  • 基金资助:

    国家自然科学基金项目(No.41302095和No.41302119)和长江大学青年科技创新团队基金项目(2015cqt04)资助。

Abstract:

A large scale of gentle slope sedimentary background indicating a good exploration prospect is developed in Neogene Shawan Formation, Chunguang block Junggar Basin. On the basis of core, drilling, well-logging and seismic data, sedimentary sequence and hydrocarbon reservoir are analyzed in this study. The sedimentary characteristics in the 1st Member of Shawan Formation are defined as follows: in the early stage of base level rise, the sand body in the braided river is developed contiguously with its flank cutting the alluvial fan; in the late stage of rise, the flood plain separates the alluvial fans and meandering stream systems. A large area of alluvial fans and braided rivers start to develop again in the falling cycle, presenting a vertical cycle characteristic of retrogradation, flooding mudstone and proradation. This paper summarizes the requirements for the development of lithologic hydrocarbon reservoirs related to alluvial fan-river sedimentary system in large slope area: (1) The sedimentary differentiation caused by base level cycle provides a material base for the development of lithologic trap: large-scale alluvial fan-braided river sandbank lithologic traps are developed in the early stage of base level rise, and meander sandbank traps are developed in the later stage; (2) Flooding mudstone in the later stage of base level rise is the roof condition for the development of lithologic reservoirs; (3) Unconformity surface and its related permeable zone provide the drainage conditions for braided sandbank lithologic reservoirs, and the reasonable disposition of faults and permeable sand body of braided rivers provide the drainage conditions for the formation of meander sandbank lithologic reservoirs. In the ascending cycle of base level, alluvial fan-braided river sandbank and meander sandbank are reasonably matched with the roof condition and channel condition, indicating a favorable exploration prospect.

Key words: slope, base level, alluvial fan, meandering stream, lithologic reservoirs, glutenite, Shawan Formation

摘要:

准噶尔盆地春光区块新近系沙湾组有大型缓斜坡沉积背景,具有良好勘探前景。以岩心、钻井、测井及地震资料为基础,开展沉积层序及油气藏分析,明确了沙湾组一段沉积特征:基准面上升早期,辫状河砂体连片发育,其侧翼方向与冲积扇切割接触;上升晚期泛滥平原分隔冲积扇及曲流河体系;下降旋回冲积扇与辫状河重新大面积发育,垂向上表现出退积、洪泛泥岩及进积的旋回特征。进一步总结得到大型斜坡区冲积-河流体系相关的岩性油气藏发育条件:①基准面旋回变化造成沉积分异是岩性圈闭发育的物质基础:上升早期形成规模型冲积扇辫流砂坝岩性圈闭,上升晚期形成曲流砂坝岩性圈闭;②基准面上升晚期洪泛 泥岩层是岩性油气藏发育的顶板条件;③不整合面及其相关渗透层是辫流砂坝岩性油气藏形成的疏导条件,断裂与渗透性辫状河砂体合理配置是曲流砂坝岩性油气藏形成的疏导条件。在基准面上升旋回中,冲积扇辫流砂坝及曲流砂坝岩性圈闭与顶板和疏导条件合理匹配,具有较大的勘探前景。

关键词: 斜坡, 基准面, 冲积扇, 曲流河, 岩性油气藏, 砂砾岩, 沙湾组

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