同步荧光光谱多点函数拟合确定原油样品浓度技术

目前油田使用的定量荧光录井中存在二维发射光谱单一峰值浓度的定量测量范围小、多次稀释增大了人为误差和浪费的问题.利用同步扫描荧光光谱技术,在10^-4g/L至10g/L浓度范围内获取胜利油田原油样品在不同浓度下波长差为40nm的正己烷萃取液的同步光谱,发现不同的浓度下同步光谱不仅表现为峰高变化,峰位也有显著变化.选取了最具代表性的7个峰值,将光谱数据在非线性范围内进行多峰值的最小二乘法浓度响应函数拟合,多点同时定量,所得误差小于5%,重复率和准确率较高.图1表2参9

A new method for concentration determination of crude oil sample using multipoint function simulation of synchronous fluorescence spectrum

Fluorescence techniques are among the most important analytic methods in petroleum logging,but the present techniques in oilfields still have some drawbacks such as the limited concentration range and the lower accuracy.Crude oil samples in the Shengli Oilfield were investigated by using synchronous fluorescence spectroscopy(SFS).The obtained SFS spectra show that the shapes of the spectra change a lot with the change of the sample concentration.Based on the change of the peak height and position,a new method for concentration determination of crude oil sample using multipoint function simulation is introduced.Experiments show that,in the concentration range from 10-4 g/L to 10g/L,this method has a lower relative deviation fewer than 5% compared with the traditional fluorescence techniques.The results suggest that the newly developed method may become a useful means in petroleum logging.