激光拉曼技术评价沉积有机质热成熟度

Thermal maturity evaluation of sedimentary organic matter using laser Raman spectroscopy

在澳大利亚联邦科学与工业研究组织能源组对激光拉曼技术评价有机质成熟度研究成果RaMM(1)和RaMM(2)的基础上,提出了可以评价沉积有机质热成熟度的激光拉曼技术新模型RaMM(P),模型使用范围为0.4%<Rr(镜质组随机反射率)<2.5%,其具有样品量小、微区(约2μm)无损分析、无需镜下区分不同显微组分(镜质组、惰质组)的特点。RaMM(P)模型在不同层系煤(二叠系、石炭系)、富氢煤与贫氢煤(镜质体反射率受到抑制和增强)以及海相泥岩分散有机质中的应用结果表明,该方法可以有效评价沉积有机质热成熟度,能反映镜质体反射率异常的问题;同时将RaMM(P)与RaMM(1)和RaMM(2)方法进行了对比讨论。该方法在沉积分散有机质热成熟度评价,尤其是镜质体缺少/缺失或镜质体反射率受到抑制或镜质体识别困难的沉积地层具有广阔的应用前景。

Based on RaMM（1）and RaMM（2）,which are the findings from a research conducted by the energy group of Commonwealth Scientific and Industrial Research Organization（CSIRO）,this paper proposes a new technical model RaMM（P）,of which the vitrinite random reflectivity is within the range of 0.4%to 2.5%,to evaluate the thermal maturity of sedimentary organic matter using laser Raman spectroscopy.RaMM（P）is characterized by small quantity of demanded samples,non-destructive analysis of micro-zone（around 2μm）,and no need to discriminate microscopic macerals（vitrinite or inertinite）.RaMM（P）model is applied in researches of different coal series（Permian and Carboniferous）,perhydrous and subhydrous coals（the suppression or enhancement of vitrinite reflectivity）,and dispersed organic matter（DOM）in marine mudstone.Results show that RaMM（P）can effectively evaluate the thermal maturity of DOM and identify abnormal vitrinite reflectivity.In addition,this paper also performs a comparative analysis on RaMM（1）,RaMM（2）and the proposed model RaMM（P）.The RaMM（P）model has a broad application prospect in thermal maturity evaluation of DOM,especially for the sedimentary strata with little or no vitrinite,or for those which are difficult to recognize due to the suppression of vitrinite reflectivity.