用拉曼光谱研究中低成熟度有机质的成熟度演化

The application of Raman spectrum in the study of organic materials maturity evolution has been paid more and more attention. However, the organic materials with low-maturity value was excited to generate a lot of fluorescence when it was measured under Raman instrument. At present, the conventional Raman analysis cannot accurately detect the Raman characteristic peak parameters of the organic materials, which seriously hinders the application of Raman spectroscopy in the study of organic matter maturity evolution. In this paper, the Surface Enhanced Raman Scattering (SERS) technology of the nanomaterials and quantum calculation were introduced in the process of Raman analysis of organic materials. Several important things were discussed: 1. Fluorescence elimination technology of nanomaterials in Raman analysis of the organic samples with a low-maturity value; 2. Improve the homogeneity of the organic samples during the Raman analysis by means of the special crushing and the mixing with the nanomaterials; 3. Optimize the method of data collection and organization, improve the accuracy of Raman analysis of organic materials; 4. Introduce the quantum calculation, comprehensively understand the relationship between Raman parameters of organic matter and its maturity evolution. 5. Find the relationship between the Raman maturity of organic materials and hydrocarbon generation kinetics to make its application in the geological condition. Through the study in this project, it is expected to be a comprehensive understanding of the relationship between Raman analysis of organic materials and its maturity evolution. Therefore, it has important scientific significance and application value.

拉曼光谱在研究有机质成熟度演化方面的应用得到了人们越来越多的关注。但是低成熟度有机质在拉曼测试过程中产生大量的荧光，目前常规的测试方法难于准确检测得到有机质的拉曼特征峰参数，严重阻碍了拉曼光谱在研究有机质成熟度演化方面的应用。本项目通过在有机质拉曼测试过程中引入纳米材料的拉曼表面增强(SERS)技术和量子计算，重点解决几个问题：1.纳米材料在低成熟度有机质样品拉曼测试过程中的荧光洇灭技术；2.通过样品的特殊破碎和纳米材料混合方法解决在拉曼测试过程中有机质样品均一性问题；3.改进数据收集和处理方案，提高有机质拉曼测试精度； 4.引入量子计算，全面认识有机质拉曼参数与其成熟度演化的关系；5.将有机质拉曼成熟度与生烃动力学结合起来，使其在地质方面得到合理的应用。通过本项目的研究，可望在有机质拉曼分析与其成熟度演化的关系有一个全面的认识。因此，具有重要的科学意义和应用价值。

拉曼技术在有机质成熟度方面的应用越来越得到众多专家的关注。但是目前专家在检测有机质成熟度时仅能相对较准确的获得成熟度高的有机质拉曼参数。而低成熟度有机质在拉曼检测过程中会产生大量的荧光，这些荧光会抬升有机质拉曼谱图中的基线，甚至掩盖到有机质的两个特征峰D和G峰，同时荧光在有机质拉曼谱图中的峰型并不固定，导致研究人员很难获得低成熟度有机质准确的拉曼参数，严重影响到拉曼技术在有机质成熟度方面的应用。.本项目研究内容主要包含：1.针对低成熟度有机质的表面增强拉曼光谱的实验操作流程和有关纳米材料的研制；2.针对国内外的典型的煤和II型页岩的低成熟度有机质的拉曼成熟度研究；3.有机质拉曼成熟度在地质方面的应用（这里以海底滑坡为例）。.重要结果：经过大量的对比实验，1.我们发现纳米银是能够对有机质表面增强拉曼最有效的纳米材料；2.有机质在表面增强拉曼图谱中特征峰位置不会被改变，但是信号会明显增强，而荧光会受到一定程度的抑制；3.有机质的拉曼成熟度演化仅与其类型有关，而与采样地点无关，煤和II型干酪根的拉曼成熟度演化明显不同。.关键数据：我们获得煤的拉曼成熟度与拉曼参数的关系为Ramcoal%=0.24835+8.38036×10^(-7) EXP(0.05817×Δ_((G-D)))；II型干酪根的拉曼成熟度与拉曼参数的关系为RamkerogenII%=0.60055+〖1.20807×10〗^(-13) EXP(0.1126×Δ_((G-D)))。纳米银初始粒径15.5~21.2nm，两年之后38.6~42 nm。.科学意义：1.拉曼检测与传统镜质体的检测相比具有客观、准确、简易、高效的特点，获得高精度低成熟度有机质拉曼参数可以完善有机质的拉曼成熟度模型；2.传统的镜质体在低成熟度有机质的成熟度变化不明显，而有机质拉曼参数对低成熟度有机质的成熟度改变则较为敏感，可以借此对有机质刚开始变质时的成熟度改变进行对比。