准噶尔盆地高压带碳酸盐胶结层的分布及特征

Distribution and characteristics of carbonate cements in overpressure zone of Junggar Basin

张立强 罗晓容

Zhang Liqiang Luo Xiaorong

中国石油大学 地球科学与技术学院, 山东 青岛 266555 2. 中国科学院 地质与地球物理研究所, 北京 100029

School of Geosciences, China University of Petroleum, Qingdao, Shandong 266555, China 2. Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100029, China

利用镜下观察、测井解释及氧碳同位素分析等方法,在分析碳酸盐胶结物特征的基础上,探讨了准噶尔盆地南缘古近系安集海河组高压带内碳酸盐胶结层的分布及形成环境.安集海河组超压带砂岩碳酸盐胶结物主要为连晶状铁质亮晶方解石,胶结层具有低声波时差、较高电阻率、低自然伽马值等特征.纵向上,超压带内的钙质胶结层主要分布于压力释放带及超压过渡带,包括超压顶界上部和下部,超压带内砂岩发育段的顶部和厚层超压泥岩中的岩性过渡带.大部分胶结物具有氧同位素呈高负值的特征,是晚期较高温度环境下,先于或同时于油气运移期形成的.

Based on studies of carbonate cement characteristics,the distribution and generation environment of carbonate cements in overpressure zone of the Paleogene Anjihaihe Formation in the southern margin of Junggar Basin have been discussed in this paper by means of thin section observation,well-logging interpretation and O-C isotope analysis.The carbonate cements in the study area are mainly composed of sparry ferri-calcite in connected-crystal form,characterized by low AC,high RT and low GR.Vertically,the cemented layers mainly locate in the pressure-released zone and the overpressure transition zone,including the upper and the lower parts of overpressure top surface,the top of sandstone belt in the overpressure zone as well as the lithologic transition belt in thick overpressure mudstone.Most of the carbonate cements have high negative oxygen isotope values.They were formed before or during petroleum migration under high temperature.

中央高校基本科研业务费专项资金;国家重点基础研究发展计划“973计划”项目(2011CB201105);国家科技重大专项项目(2011ZX05008-004)资助

https://doi.org/10.11781/sysydz201104388