单个烃类包裹体组分及成熟度紫外拉曼光谱定量表征

Hydrocarbon inclusions are the key evidence for determining the stage of petroleum accumulations. However, due to the fractionation effect of petroleum, water washing in reservoir, and other factors, there are differences in composition and fluorescence characteristics of hydrocarbon inclusions in the same generation, and the analysis of individual hydrocarbon inclusions is often restricted, which lead to difficulties in the interpretation of analytical data. Ultraviolet (UV) Raman spectroscopy has become the most potential and effective method to identify and analyze single hydrocarbon inclusions because it can avoid the interference of fluorescence and improve the signal-to-noise ratio (SNR) of Raman spectrum. In this project, we plan to synthesize standard hydrocarbon inclusions as references by synthetic fluid inclusions technique with analyzed petroleum. UV Raman spectroscopy is used to analyze the standards (synthetic hydrocarbon inclusions) and obtain the Raman characteristics of the main components. Based on the content of components and maturity of petroleum, and Raman spectrum parameters of the main components in hydrocarbon inclusions, the method will be established for qualitatively and quantitatively determining the petroleum types, components and maturity of single hydrocarbon inclusion by UV Raman spectroscopy. The spatial distribution characteristics of different hydrocarbon molecules in inclusions were analyzed based on microspectral imaging technique. The effects of capture process on the heterogeneity of hydrocarbon inclusions during the same period are determined by comparing the known hydrocarbon compositions with hydrocarbon inclusions and the difference of parameters between hydrocarbon inclusions. We hope that breakthrough progress will be made in the analysis of individual hydrocarbon inclusion through this study.

烃类包裹体是划分油气成藏期次的重要依据，但由于油气分馏效应、水洗作用等因素导致同期烃类包裹体成分和荧光特征出现差异，加上单个烃类包裹体成分分析受到诸多因素制约，使得分析数据解释往往遇到麻烦。而紫外拉曼光谱技术可以避免荧光的干扰，提高了拉曼光谱信噪比，成为分析单个烃类包裹体最有潜力的有效方法。本项目拟采用人工合成包裹体技术制备已知组成和成熟度的标型烃类包裹体，利用紫外拉曼光谱技术分析标型样品并获取主要组分的拉曼特征；基于已知油气的组分、成熟度和主要组分的拉曼光谱参数，建立单个烃类包裹体油气类型、组分及成熟度的紫外拉曼光谱定性和定量表征方法；基于显微光谱成像技术分析不同烃类分子在包裹体中的空间分布特征；通过已知油气成分与烃类包裹体组分之间对比、以及单个烃类包裹体之间的各项参数对比，明确油气捕获过程对同期烃类包裹体非均一性的影响。通过本研究，以期在单个烃类包裹体分析方面取得突破性进展。

在系统统计分析各类有机分子拉曼光谱特征基础上，提出了不同类型烃类的拉曼光谱判识依据。采用人工合成流体包裹体技术合成具有不同成熟度、不同组分含量、不同金刚烷含量的标型烃类包裹体，利用紫外拉曼显微光谱技术对标型样品进行了系统分析，获得了不同标型烃类包裹体的典型拉曼光谱特征。通过对标型烃类包裹体紫外拉曼光谱和显微成像分析获取包裹体内部组成及其分布特征，基于已知油气的组分、成熟度和主要组分拉曼光谱特征，建立了单个烃类包裹体主要组分、金刚烷含量及成熟度的紫外拉曼光谱定量关系。通过对实际样品研究，在烃源岩排烃流体压力、油气成藏等方面取得重要进展，同时对油气包裹体紫外拉曼光谱分析技术存在的问题进行了探讨。主要成果包括：.（1）对原油成熟度有关的生物标志化合物进行了相关性分析，并结合拉曼光谱特征得到了一系列拉曼参数与生物标志物成熟度参数之间的定量公式。建立了原油的紫外拉曼光谱参数与原油中主要组分含量的关系，与芳烃含量呈较好的正相关性。.（2）对制作的标准浓度烃类包裹体样品进行了激光拉曼光谱测试，利用单金刚烷755.6 cm-1和双金刚烷706 cm-1标志峰，分别联合正己烷和甲苯在1140.5 cm-1和1604 cm-1的峰为内标参考峰，确定了一系列峰参数与金刚烷浓度的定量关系公式，双金刚烷具有更高的相关性。饱和烃对定量关系影响较大，芳烃影响较小。.（3）通过富有机质页岩中纤维状方解石脉的流体包裹体研究，获得了烃源岩幕式排烃和超压流体的直接证据。.（4）对沥青拉曼光谱进行了系统研究，并利用储层固体沥青拉曼光谱和流体包裹体特征研究了渤海湾盆地杨税务潜山和准噶尔盆地准中地区三工河组的油气成藏特征。.（5）以东营凹陷为例，结合各种光谱技术和地球化学分析，建立了荧光光谱定量表征不同成熟度的同源混合原油方法。