油气地质与采收率2018，Vol.25Issue(3)：68-76,9.DOI:10.13673/j.cnki.cn37-1359/te.2018.03.010
江西修武盆地早寒武世热液活动对有机质富集的影响
Effect of hydrothermal activity on the enrichment of sedimentary organic matter at Early Cambrian in the Xiuwu Basin
摘要
Abstract
The Lower Cambrian is the main target intervals of marine shale gas exploration and exploitation in China.Shale gas content varies greatly in different intervals and how to determine favorable targets is an important problem to be solved urgently.Taking Well XN-1 in Xiuwu Basin as an example,according to core description,logging data analysis,mineral and elemental composition analysis and total organic carbon (TOC)content tests,the shale in Lower Cambrian Wangyinpu Formation and Guanyintang Formation was studied.Results show that water redox conditions and bioproductivity control the enrichment of sedimentary organic matter.Hydrothermal activities are helpful for the increase of reducibility of seawater and enhancing bioproductivity,and thus controls the enrichment of sedimentary organic matter and the enrichment of shale gas is further affected.The water reducibility during the deposition of SQ1 at early Cambrian varies greatly,and it is generally strong during the deposition of SQ2 and SQ3 of the Wangyinpu Formation.The reducibility of all the three sequences is stronger than that during the deposition of SQ4 and SQ5.The bioproductivity during the deposition of SQ3 is the highest and little difference in the bioproductivity has been found between SQ 1 and SQ2,both of which show higher values than that of SQ4 and SQ5.Siliceous origin of SQ1 varies greatly in the study area;most siliceous minerals of SQ2 and SQ3 are hydrothermal origin,whose content is high;content of hydrothermal origin siliceous minerals drops in SQ4 and terrigeneous siliceous content increases;siliceous minerals of SQ5 originate from normal terrigeneous clastic deposition.SQ2 and SQ3 are favorable targets of shale gas in the Lower Cambrian.关键词
有机质富集/热液活动/氧化还原环境/生物生产力/沉积环境Key words
enrichment of organic matter/hydrothermal activity/redox conditions/bioproductivity/deposition environment分类
能源科技引用本文复制引用
刘天琳,姜振学,刘伟伟,张昆,谢雪恋,阴丽诗,黄一舟..江西修武盆地早寒武世热液活动对有机质富集的影响[J].油气地质与采收率,2018,25(3):68-76,9.基金项目
国家科技重大专项“五峰—龙马溪组富有机质页岩储层精细描述与页岩气成藏机理”(2016ZX05035-02),国家自然科学基金项目“页岩非均质性和微-纳米孔喉结构对含气性的控制机理”(41472112). （2016ZX05035-02）
