准噶尔盆地钙质夹层成因及层序地层学意义

Origin of calcareous interbeds and its significance of sequence stratigraphy in Junggar Basin

以准噶尔盆地腹部石南井区为例,探讨了侏罗系西山窑组三角洲前缘亚相油气储层中钙质夹层的成因机制,揭示了其空间分布规律。研究结果表明,钙质夹层主要分布在三角洲前缘水下分支河道的底部和河口坝的顶部,可以作为高分辨率等时地层对比的标志。对石南井区含油层段进行了高分辨率层序地层学分析,建立了该区层组(六级层序)级别的地层叠置模式及高分辨率等时地层格架。

The origin of calcareous interbeds in Xishanyao Formation of the Jurassic in Shinan area of Junggar Basin was studied. The observation and study on cores and quantitative information about logging data abundantly show the occurrence of lithology and logging configuration of calcareous interbeds in the delta front reservoir of the Shinan area. The laws of spatial distribution of calcareous interbeds formed by carbonate cementation were discussed. The calcareous interbeds distribute on the top of debouch bar and the bottom of branched underwater channel in the front of delta, which becomes the symbol of subdivision and isochronous contrast of bed sets. At the same time, it is pointed that the calcareous intebeds may become the symbol of high-resolution sequence stratigraphic isochronous contrast. The stratigraphic construction model was developed and high-resolution chrostratigraphic framework was given.