中国石油勘探 ›› 2018, Vol. 23 ›› Issue (4): 11-20.DOI: 10.3969/j.issn.1672-7703.2018.04.002

• 勘探管理 • 上一篇    下一篇

断陷湖盆异重流沉积特征与分布模式——以歧口凹陷板桥斜坡沙一下亚段为例

周立宏, 陈长伟, 韩国猛, 肖敦清, 汤戈, 王锦程   

  1. 中国石油大港油田公司
  • 收稿日期:2017-12-09 修回日期:2018-05-31 出版日期:2018-07-15 发布日期:2018-07-11
  • 基金资助:
    国家科技重大专项“大型油气田及煤层气开发”(2016ZX05006-005)。

Sedimentary characteristics and distribution patterns of hyperpycnal flow in rifted lacustrine basins: a case study on lower Es1 of Banqiao slope in Qikou sag

Zhou Lihong, Chen Changwei, Han Guomeng, Xiao Dunqing, Tang Ge, Wang Jincheng   

  1. PetroChina Dagang Oilfield Company
  • Received:2017-12-09 Revised:2018-05-31 Online:2018-07-15 Published:2018-07-11
  • Supported by:
     

摘要: 地震、岩心、测井、录井、试油及分析化验资料综合研究表明,歧口凹陷板桥斜坡沙一下亚段主力油气储层为异重流沉积砂岩。异重流沉积总体处于半深湖—深湖环境,其岩性组合表现为灰黑色泥岩夹中—细砂岩或互层沉积,砂岩段沉积粒序呈一系列向上变粗单元(逆粒序)和向上变细单元(正粒序)成对出现的特征,发育层内侵蚀面,可见交错层理、平行层理、爬升层理及透镜状层理等多种类型的流水成因层理构造。异重流沉积包括侵蚀水道、水道复合体、分支水道、近端沙坝、远端沙坝、席状朵体6个微相,其中水道复合体微相沉积砂岩具有单层厚度大、粒度粗、分选好、泥质含量低、储集物性好的特点。通过地震属性、砂岩厚度及岩心观察,明确了板桥斜坡沙一下亚段异重流沉积体系展布,针对性预探部署获得了良好的勘探成效,单井试油产量高,稳产效果好,展示了陆相断陷盆地中深层异重流沉积岩性油气藏勘探的良好前景。

 

关键词: 断陷盆地, 歧口凹陷, 异重流, 岩性油气藏

Abstract: Comprehensive studies on seismic, core, well logging, mud logging, well testing and laboratory data show that the primary reservoirs in lower Es1(the lower first sub-member of Shahejie Formation) of the Banqiao slope in the Qikou sag are sand reservoirs developed with hyperpycnal flow. Such sediments are generally located in a semi-deep to deep lacustrine environment. The lithologic composition is characterized by gray-black mudstone with medium-fine sandstone or their interbeds. In the sandstone segment, the sequence of sedimentary grains is a series of upwardly-coarsening units (inverse grain sequence) in pairs with a series of upwardly-thinning units (positive grain sequence); intralayer eroded surfaces are developed; and various types of fluviatile bedding structures can be found, such as cross-bed bedding, parallel bedding, climbing bedding and lenticular bedding. Hyperpycnal flow sediments involves eroded water channels, channel complexes, branch channels, proximal sand bars, distal sand bars and sheet lobes, of which the channel complexes have large monolayer thickness, coarse granularity, good sorting, low shale content and good reservoir properties. According to seismic attributes, sandstone thickness and core observations, the sedimentary distribution of the hyperpycnal flow has been analyzed in lower Es1 of the Banqiao slope in the Qikou sag. Based on the result, the targeted pre-exploration plan has delivered good results; the single-well production test is high and stable. This proves the promising exploration of lithologic reservoirs in the middle and deep hyperpycnal flow in continental rifted basins.

Key words: rifted basin, Qikou sag, hyperpycnal flow, lithologic reservoir

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