100MPa压力下温度和水对干酪根结构状态影响的实验研究

Experimental study of the influence of temperature and water on the structure state of kerogen at 100 MPa pressure

为了实验验证变质沉积物中的碳质物拉曼光谱地质温度计的可用性,利用冷封口式高温高压水热系统将焊封金管内的干酪根于100MPa压力和温度(250-700℃)、有水和无水条件下处理24小时,激光拉曼探针(LRM)分析表明,实验所得碳质物的一级和二级拉曼谱特征(拉曼峰的存在、峰的位置、宽度、高度和面积)随温度系统地变化,所得碳质物的D/O比值随温度升高而减小,但在D/O比-温度关系图上-500℃处有一拐点(极小)。实验条件下处理的干酪根的显微富利叶变换红外谱(micro-FTIR)分析表明,脂族C-H和芳族C-H吸收峰的相对强度在500℃左右急剧变化以及在700℃的实验产物中仍存在含氢的功能团。高温高压条件下,水的存在不利于碳质物的石墨化(有序化)。

In order to experimentally verify the feasibility of the Laman spectroscopic geothermometer of carbonaceous matter from metasediments, kerogen in a sealed gold capsule was held at 100 MPa pressure and at temperatures of 250 similar to 700degreesC under dry and hydrous conditions for 24 hours, using a cold-seal high pressure-temperature hydrothermal system. Laser Raman microspectroscopic study of the run products documented systematic changes in both the first- and second-order spectral features (the existence of the Raman peaks, the peak position, width, height and area) with temperature, and the D/O ratio values of the carbonaceous matter obtained decrease with increasing in temperature, but an inflection point (minimum) was observed at similar to 500degreesC in D/O ratio-temperature plot.. The micro-Fourier transform infrared spectroscopic analysis of the kerogen treated under run conditions showed that the relative intensity of the aliphatic C-H bands to the aromatic C-H stretching dramatically changed at temperature of similar to 500degreesC, as well as hydrogenated functional groups still existed in the 700degreesC run products. The presence of water is unfavorable to the graphitization (ordering) of carbonaceous matter.