古地理学报 ›› 2015, Vol. 17 ›› Issue (3): 381-392. doi: 10.7605/gdlxb.2015.03.32

• 古地理学及矿产资源 • 上一篇    下一篇

柴达木盆地西部地区古近系下干柴沟组咸化湖相泥页岩储集层特征

原园1,2,姜振学1,2,李卓1,2,赵若彤1,2,李鹏1,2,崇明浩1,2   

  1. 1 中国石油大学(北京)油气资源与探测国家重点实验室,北京 102249
    2 中国石油大学(北京)非常规天然气研究院,北京 102249
  • 收稿日期:2014-11-17 修回日期:2015-01-21 出版日期:2015-06-01 发布日期:2015-06-01
  • 作者简介:原园,女,1986年生,中国石油大学(北京)博士研究生,主要从事非常规油气地质学的研究。E-mail: ycyy7796@126.com。
       通讯作者简介 姜振学,男,1963年生,教授,主要从事含油气盆地分析、常规和非常规油气形成与分布、常规和非常规油气资源评价方面的研究。E-mail: jiangzx@cup.edu.cn。
  • 基金资助:
    国家科技重大专项“页岩气成藏主控因素研究”(编号:2011ZX05018-002)资助

Reservoir characteristics of salt-water lacustrine shale of the Paleogene Xiaganchaigou Formation in western Qaidam Basin

Yuan Yuan1,2, Jiang Zhenxue1,2, Li Zhuo1,2, Zhao Ruotong1,2, Li Peng1,2, Chong Minghao1,2   

  1. 1 State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum(Beijing),Beijing 102249
    2 Unconventional Natural Gas Institute,China University of Petroleum(Beijing),Beijing 102249
  • Received:2014-11-17 Revised:2015-01-21 Online:2015-06-01 Published:2015-06-01
  • About author:Yuan yuan,born in 1986,is a Ph.D. candidate of China University of Petroleum(Beijing). Her academic interest is focused on unconventional oil and gas geology.E-mail: ycyy7796@126.com.
       About the corresponding author Jiang zhenxue,born in 1963,is a professor of China University of Petroleum(Beijing). He is mainly engaged in oil and gas basin analysis,conventional and unconventional oil and gas formation and distribution,and resources evaluation. E-mail: jiangzx@cup.edu.cn

摘要: 中国已获得湖相页岩气勘探开发的重要突破,但对于咸化湖盆环境泥页岩储集层特征的研究较少。作者对柴达木盆地西部地区古近系下干柴沟组湖相泥页岩储集层开展有机地化、岩矿组成、储集层孔隙结构等特征的研究。(1)研究区泥页岩有机质丰度在0.12%~1.35%之间,具有强烈的非均质性,有机质类型以Ⅱ型为主,氯仿沥青“A”含量较高。(2)泥页岩中碳酸盐岩矿物含量最高,平均27.8%,黏土矿物和石英含量次之,有38.2%的样品检测出硬石膏,反映典型的咸化环境特征。(3)扫描电镜观察有机质孔隙发育较少,形状不规则且孔径较大,粒(晶)间孔隙直径多以微米级为主,微裂缝宽多小于1μm;低温气体吸附测试显示,中孔提供了主要的孔比表面积和孔隙体积,氯仿沥青“A”的存在对样品孔隙结构产生影响。(4)研究区泥页岩储集层中黏土矿物含量低而脆性矿物含量高,与北美页岩气产层及四川盆地龙马溪组页岩储集层岩矿特征类似,易于产生裂缝,有利于页岩气的后期开采。

关键词: 储集层, 氯仿沥青“A”, 泥页岩, 咸化湖盆, 古近系, 柴达木盆地

Abstract: Great breakthrough has been made in the exploration of lacustrine shale gas in China, but little research on reservoir of salt-water lacustrine shale was carried out. Organic geochemical analysis,mineral composition analysis and pore structure analysis of reservoir of the Palaeogene Xiaganchaigou Formation lacustrine shale in western Qaidam Basin has been done by the authors. (1)The organic content has intense heterogeneity in the 0.12%~1.35% range,the content of chloroform bitumen “A”is high and the organic matter is mainly of type Ⅱ.(2)The content of carbonate is the highest with an average of 27.8%,and then clay minerals and quartz. There are 38.2% of the samples have anhydrite,which reflects the typical salt ̄water lacustrine environments. (3) The organic matter micro-pores observed in the SEM are less developed,the shape is irregular and pore size is large. Intergranular pores are mainly micronl ̄sized in diameter, while micro-fractures are mainly less than 1μm in width. Mesopores have most of specific surface area and pore volume of shale pores,and are main places for gas adsorption and storage. The chloroform bitumen“A”influenced the pore structure of the samples. (4)The content of clay minerals is low and brittle minerals is high in research area,which is comparable with the series of gas-containing shales in U.S. and with the Lower Paleozoic shale in the Sichuan Basin,are conducive to creating cracks,and are easy for fracturing.

Key words: reservoir, chloroform bitumen“A”, shale, salt-water lacustrine basin, Palaeogene, Qaidam Basin

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