以初级生产力与固碳规律为线索探讨陆相页岩中有机质的富集规律  

Discussion on Enrichment Law of Organic Matter in Continental Shale with Clue of Primary Productivity and Carbon Storage Law

作　　者：毛小平[1] 陈修蓉 陈永进[1] 李岁岁 李振 朱启轩 Mao Xiaoping;Chen Xiurong;Chen Yongjin;Li Suisui;Li Zhen;Zhu Qixuan(School of Energy Resources,China University of Geosciences,Beijing 100083,China;Tsinghua University,Beijing 100084,China)

机构地区：[1]中国地质大学能源学院,北京100083 [2]清华大学,北京100084

出　　处：《地球科学》2024年第4期1224-1244,共21页Earth Science

基　　金：省级重大创新工程项目(No.[2022]ZD003).

摘　　要：陆相优质烃源岩主要在盆地中心深湖-半深湖等深水环境发育,但大量页岩气勘探证实,富有机质页岩更靠近湖盆边缘,因此有必要深入剖析陆相湖盆有机质富集的规律.采用类比法对比页岩油气、煤的成矿条件,结合湖泊的初级生产力、固碳速率、化石发育,采用古地貌及埋藏史恢复手段,提出了页岩发育于浅水局限环境的六大证据.研究发现,页岩油气和煤具有相似的成矿模式;与浅水环境的煤、蒸发盐岩等具有共生关系;浅水环境下固碳速率远大于深水环境.结论是,页岩油气富集于浅水湖湾、间湾等封闭-半封闭环境;最大湖泛期凝缩段应为贫有机质段.最后以松南等地区进行验证,说明本结论具有普适性,可更好地指导陆相页岩油气勘探.It is generally believed that it is easy to enrich oil and gas in deep-water environments such as deep lacustrine to semideep lacustrine in continental basins,but a large number of shale gas exploration has proved that shale gas reservoirs are generally located closer to the edge of lacustrine basins,so it is necessary to further study the law of organic matter enrichment in continental lacustrine basins.In this paper,the metallogenic conditions of shale oil,gas and coal are compared by analogy method.Combined with the primary productivity of the lake,the rate of carbon sequestration and fossil development,the paleo-geomognomy and burial history recovery means are used to put forward six evidence that shale developed in shallow water restricted environment.It is found that shale oil,gas and coal have similar metallogenic patterns,and have a symbiotic relationship with coal and evaporative salt in shallow water environment.The carbon sequestration rate in shallow water environment is much higher than that in deep water environment.The conclusion is that shale oil and gas are enriched in closed to semi-closed environment such as shallow lake bay and interbay.The condensed section of the maximum flood period should be the organic-poor section.Finally,the results are verified in Songnan area,indicating that this conclusion is universal and can guide shale oil and gas exploration better.

关 键 词：页岩气 烃源层 湖湾 最大湖泛期 叶肢介 初级生产力 矿床学 

分 类 号：P618[天文地球—矿床学]