涪陵海相页岩生物成因硅特征及确定方法

Characteristics and Determination Method of Fuling Marine Shale Biogenic Silicon

通过对涪陵页岩气田奥陶系五峰组-志留系龙马溪组下段海相暗色页岩岩心样品、薄片观察、岩石学特征、TOC含量与硅质含量相关性分析,证实研究区上奥陶统五峰组-下志留统龙马溪组海相页岩底部富有机质页岩中部分硅质为生物成因,其含量最高可达50.0%以上,可占到硅质总量的70.0%,具有富含海洋有机质、笔石化石种类丰富、有机质丰度高、富含生物硅的特征。利用元素录井快速确定生物硅含量的方法,可为国内其他页岩气探区提供参考。

Through observation of the core sample of marine dark shale and slice in the lower section of Ordovician Wufeng Formation-Silurian Longmaxi Formation in Fuling shale gasfield and analysis of correlation between TOC content and siliceous content, this paper verifies that the part of silicon is biogenic origin in the rich organic matter at the bottom of marine shale of the upper Ordovician Wufeng Formation-lower Silurian Longmaxi Formation. The highest amount of the rich organic matter reaches 50.0%, accounting for 70.0% of total silicon, with the characteristics of rich marine organic material, rich variety of graptolite fossil, high abundance of organic matter and rich biosilicon. The method of fast determining biosilicon content by Using element logging contributes to guiding the other shale gas exploration areas in China.