显微荧光光谱参数及其在单个油包裹体族组分和成熟度预测中的应用——以柴北缘冷湖地区为例

The composition of individual oil inclusion is crucial to process and mechanism study of hydrocarbon migration and accumulation. People have done much previous research work and put forward destructive testing, thermal dynamics simulation, microscopic spectra analysis techniques on composition of individual oil inclusion. However, these techniques are deeply immature. In these methods, microscopic fluorescence spectra test has advantages of high spatial resolution, simplicity of operator and non-destructive. Besides, fluorescence spectral parameters λmax and Q650/500 are in good correlations with the density, viscosity and relative content of gross compositions. Fluorescent color and maturity are better correspondence also. Howerer, now it only stays at stage of qualitative analysis. To this problem, this project intends to select Lenghu area in the North Qaidam Basin where oil source is single , crude oil composition and maturity of the family has a large distribution range as the study area, then construct fluorescence spectrum parameters with geochemical significance. On this basis, the standard relational curves and standard relational plate between fluorescence spectrum parameters and oil gross components , maturity will be built combined with the existing spectral parameters. Then, a new method to estimate the gross components and maturity of individual oil inclusion will be built. This method will provides evidence of inclusions for migration and accumulation of oil and gas research.

单个油包裹体的组分对油气运移成藏过程和机理研究至关重要。前人对它开展了大量研究，并提出了破坏性测试、热动力学模拟、显微光谱分析等方法，但这些方法均存在一定的问题。这些方法中，显微荧光光谱测试具有高空间分辨率、操作简单，无损的优势，且光谱参数λmax和Q650/500与原油的密度、粘度、族组分的相对含量相关性较好，荧光颜色与成熟度对应性也较好。然而，显微荧光光谱目前却不能对单个油包裹体的族组分和成熟度进行定量分析。针对这一问题，本项目拟选择油源单一、原油族组分和成熟度具有较大分布范围的柴北缘冷湖地区作为研究区，构建具有地化意义的光谱参数，并结合现有光谱参数，建立它们与原油族组分、成熟度的标准关系曲线和标准关系图版，进而建立一种预测单个油包裹体族组分和成熟度的方法，从而为油气的运移成藏研究提供包裹体证据。

单个油包裹体的组分对油气运移成藏过程和机理研究至关重要,但其测试分析确是一个世界性难题。本项目拟利用高分辨率、无损的显微荧光光谱技术，探索荧光光谱与原油族组分和成熟度的关系，进而解决单个油包裹体的组分难题。为排除源的干扰，本项目选择油源单一、原油族组分和成熟度具有较大分布范围的柴北缘冷湖地区作为研究区，开展了原油族组分荧光光谱响应实验、荧光光谱与原油族组分、成熟度相关性及其应用研究。此外，还对项目开展过程中发现的新科学问题开展研究。结果表明：（1）原油荧光光谱与族组分和浓度有关并优先受控于成熟度；（2）原油荧光光谱参数之间具有相关性；（3）光谱参数与原油族组分（成熟度）间具有明显的相关性，可用于预测单个油包裹体族组分和成熟度；（4）通过透射光图片校正、荧光光谱相近性、油水包裹体共生判别，可显著提高最小捕获压力计算准确度；（5）湖相沉积碳酸盐可限定古湖水的同位素组成，依此可准确判识储层内方解石胶结物的成因。氧同位素对地质环境具有敏感性，因而可用于成岩流体示踪;(6) 钙质夹层并非都是碳酸盐矿物沉淀后“一步而蹴”的，也可形成于成岩阶段经多期水岩作用后形成。这些成果认识对于盆地流体和油气运移成藏均具有重要的参考价值。