Ⅰ型干酪根热成熟过程中拉曼光谱特征及其成熟度意义  

Characteristics and significance of maturity of Raman spectra of type Ⅰ kerogen during maturation

作　　者：单云 邹艳荣[1] 闵育顺[1] 彭平安[1] SHAN Yun;ZOU Yan-rong;Min Yu-shun;PENG Ping-an(State Key Laboratory of Organic Geochemistry,Guangzhou Institute of Geochemistry,Chinese Academy of Sciences,Guangzhou 510640,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院广州地球化学研究所有机地球化学国家重点实验室,广东广州510640 [2]中国科学院大学,北京100049

出　　处：《地球化学》2018年第5期586-592,共7页Geochimica

基　　金：国家自然科学基金创新研究群体项目(41621062);中国科学院战略性先导科技专项A类(XDA14010102)

摘　　要：对准噶尔盆地西大龙口剖面芦草沟组低成熟页岩干酪根进行高温高压黄金管热解实验,开展不同温度点页岩干酪根固体残渣的拉曼光谱研究。有机质的拉曼光谱具有2个特征峰,即D峰和G峰。随着热模拟温度的增加,特征峰的峰型都向窄而尖的形态发展,G峰拉曼位移基本不变,D峰拉曼位移逐渐减小,D峰和G峰的半高宽均逐渐变窄。随着成熟度的增加,固体有机质的分子结构逐渐向稳定的石墨化结构演变。拉曼参数和热模拟温度之间具有很好的相关性,G峰、D峰的峰间距d_((G-D))与热演化程度之间表现出很强的正相关关系,G峰半高宽与热演化程度之间表现出很好的负相关关系。在评价有机质成熟度时,分别用动力学参数Easy R_o和等效镜质体反射率_(Rmc)R_o对其进行热演化程度的标定,当成熟度为0.7%~2.0%时,两者对热演化产物的成熟度标定呈现出一致性。在本次实验中G峰半高宽和有机质成熟度之间有很好的负相关性。Artificial maturation of Lucaogou Formation low mature shale kerogen in western Dalongkou section,Junggar Basin,was performed in a closed gold tube system.The insoluble kerogen residue at different temperatures was determined by using Raman spectrascope.There were two characteristic peaks in the Raman spectra of organic matter named peak D and peak G.With the increasing of thermal simulation temperature,the shape of the two peaks were developed into a narrow and pointed forms.Peak G raman shift was almost constant while peak D raman shift was gradually decreasing.The full width at half maximum(FWHM-D and FWHM-G)of peaks gradually narrowed.The Raman spectra indicates that the molecular structure of organic matter gradually evolved into a stable graphite structure with the increasing of maturity.Raman spectra parameters had a good correlation with degree of thermal evolution.In particular,there was a strong positive correlation between the peak separation and thermal simulation temperature,and a negative correlation between FWHM-G and the degree of thermal evolution.To evaluate maturity of organic,the thermal evolution degree of insoluble kerogen residue was calibrated with the kinetics parameter EasyRo and RmcRo called equivalent vitrinite reflectance respectively.We found consistency between EasyRo and RmcRo in evaluating the maturity of thermal evolution residual when the value is between 0.7%– 2%.We also discussed the feasibility of FWHM-G in evaluating the maturity of organic matter.

关 键 词：干酪根 热解 拉曼光谱 芦草沟组 准噶尔盆地 

分 类 号：P593[天文地球—地球化学]