黔南坳陷下寒武统牛蹄塘组泥页岩埋藏史与热史研究——以贵都地1井为例  

Burial and thermal history of mud shale in Niutitang formation of lower Cambrian in southern Guizhou depression:A case study of Guidudi well 1

作　　者：聂国权 李小盼 淡永[1,2] 梁彬 张庆玉[1,2] 李景瑞 季少聪[1,2] NIE Guoquan;LI Xiaopan;DAN Yong;LIANG Bin;ZHANG Qingyu;LI Jingrui;JI Shaocong(Institute of Karst Geology,CAGS,Guilin,Guangxi 541004,China;Key Laboratory of Karst Dynamics,MNR&GZAR,Guilin,Guangxi 541004,China)

机构地区：[1]中国地质科学院岩溶地质研究所,广西桂林541004 [2]自然资源部、广西岩溶动力学重点实验室,广西桂林541004

出　　处：《中国岩溶》2021年第5期760-767,共8页Carsologica Sinica

基　　金：国家重点研发计划“古潜山和深部岩溶热储分布规律与成因机制”(2018YFC0604301);中国地质调查局地质调查项目(DD20190723,DD20190562,DD20190022)共同资助。

摘　　要：下寒武统牛蹄塘组是黔南坳陷最重要的页岩气目标层之一。为探究牛蹄塘组泥页岩的生烃演化史,文章以黔南坳陷贵都地1井为研究对象,通过对该区油气地质、地球化学分析,运用盆地模拟技术等方法,对贵都地1井牛蹄塘组埋藏史与热史进行重建。结果表明:牛蹄塘组泥页岩具有较高的有机质丰度,有机质类型为I型,已达到过成熟阶段,整体具有一定的生烃潜力;牛蹄塘组泥页岩经历了中寒武世早期—中奥陶世(466~508 Ma)的生油期和中奥陶世—中三叠世(236~466 Ma)的生气期,在中三叠世晚期(约230 Ma)达到最大埋深5740 m,最高温度约215℃;具有“短暂生油,持续生气”的特征;高热演化背景下的生烃过程为页岩气富集提供较好的基础条件,但印支期以来的构造抬升剥蚀对页岩气保存具有较强的破坏作用,保存条件是页岩气富集最重要的控制因素。The Niutitang formation of lower Cambrian is one of the most important target strata for shale gas in southern Guizhou depression.In order to explore the hydrocarbon generation and evolution of mud shale,the burial and thermal history of Niutitang formation in Guidudi Well 1 in southern Guizhou depression has been reconstructed based on petroleum geological as well as geochemical analyses by basin simulation.Results demonstrate the abundant type-I organic matter in mud shale of Niutitang formation.The organic matter has reached over-mature stage and generally has a certain potential of hydrocarbon generation.The mud shale of Niutitang formation experienced the oil-generating period from early Middle Cambrian to Middle Ordovician(about 508~466 Ma)and the gas-generating period from Middle Ordovician to early Middle Triassic(about 466~236 Ma),reaching the maximum burial depth of 5,740 m and the maximum temperature of about 215℃ in the late Middle Triassic(about 230 Ma).It has the characteristics of transient oil generation and continuous gas generation.The process of the hydrocarbon generation during the high thermal evolution can provide good basic conditions for shale gas enrichment.However,tectonic uplift and erosion since Indosinian period has had a strong destructive effect on shale gas preservation,and preservation conditions are the most important controlling factors for shale gas enrichment.

关 键 词：牛蹄塘组 埋藏史 地热史 成熟度 贵都地1井 黔南坳陷 

分 类 号：P618.13[天文地球—矿床学]