激光共聚焦扫描显微镜测定烃类包裹体气液比的误差校正研究

通过烃类包裹体PVT模拟可以重建捕获温度和捕获压力,气液比是影响PVT模拟结果的重要参数,然而由于缺少烃类包裹体标准样品,一直未能深入研究激光共聚焦显微镜气液比测定精度的问题。本文利用人工合成包裹体技术合成了一种用于校正激光共聚焦扫描显微镜(LSCM)测定气液比的烃类包裹体标准样品,根据已知的合成烃类包裹体的油气组成、捕获温度和捕获压力计算出烃类包裹体的理论气液比,并利用LSCM测定烃类包裹体的实际气液比,通过计算实际测试值与理论值的差值以分析实际测定气液比的误差,实现对激光共聚焦扫描显微镜的误差标定。实验结果证实,高分辨率的LSCM测定烃类包裹体气液比的绝对误差小于0.5%,可以为包裹体PVT模拟提供精确参数。本研究肯定了LSCM测定烃类包裹体气液比方法的准确性,进一步证实了烃类包裹体的PVT模拟结果可以为油气成藏研究提供可靠数据。

Error Correction of Vapour/Liquid Ratio of Hydrocarbon Inclusions Measured by Confocal Laser Scanning Microscope

PVT simulation of hydrocarbon inclusions can be used to reconstruct trapping temperature and pressure. Vapour/liquid ratio is an important parameter affecting PVT simulation. However, due to the lack of a hydrocarbon inclusion standard, the accuracy of the vapour/liquid ratio measured by Confocal Laser Scanning Microscope (CLSM) has not been investigated. In this paper it is proposed that a synthetic hydrocarbon inclusion standard can be used for correcting CLSM and the theoretical vapour/liquid ratio of hydrocarbon inclusions can be calculated based on the known hydrocarbon composition, trapping temperature and pressure. The actual vapour/liquid ratio can be obtained by CLSM. The differences between the actual values and theoretical values can be used to calculate the error of actual vapour/liquid ratio, so as to complete the error calibration of CLSM. Experimental results confirm that the absolute error of CLSM with high resolution is less than 0.5%, and thus CLSM can provide accurate parameters for the PVT simulation of inclusions. This study affirms the accuracy of CLSM for determining the vapour/liquid ratio of hydrocarbon inclusions, and further confirms that PVT simulation of hydrocarbon inclusions can provide reliable data for hydrocarbon accumulation.