荆门探区上奥陶统五峰组—下志留统龙马溪组页岩气地化特征

Upper Ordovician Wufeng Formation-Lower Silurian Longmaxi Formation Shale Gas Geochemical Features in Jingmen Exploration Area

基于荆门地区上奥陶统五峰组—下志留统龙马溪组页岩的沉积特征和有机地化特征在评价有利生油气层中的重要性,采用有机质丰度、类型、热演化程度对荆门探区的地化特征进行了综合评价,结果表明,荆门五峰组—龙马溪组页岩有机质丰度较高,有机碳(TOC)平均值五峰组为2.9%,龙马溪组为3.51%;有机质类型主要为II型;有机质演化程度整体较高,五峰组平均为2.85%,龙马溪组平均为2.61%,探区南北部较中心页岩品质更优,为有利区。单从页岩有机地球化学特征分析,总体上为好的烃源岩,具有良好的页岩气资源前景。

Based on the essentiality of upper Ordovician Wufeng Formation-lower Silurian Longmaxi Formation shale sedimentary and organic geochemical features in favorable hydrocarbon generation assessment in the Jingmen area,the paper has used organic matter abundance,type and thermal evolution degree carried out geochemical features comprehensive assessment in Jingmen area.The result has shown that the shale in the area has higher organic matter abundance,TOC content mean in Wufeng Formation is 2.9%,Longmaxi Formation 3.51%.Organic matter mainly belongs to type II;thermal evolution degree is rather high as a whole,Wufeng Formation mean 2.85%,Longmaxi Formation mean 2.61%.The shale quality in south and north parts is better than in central part,thus the favorable areas.Only from organic geochemical features analysis,the shale is a fine source rock as a whole with good shale gas resource prospect.