| Fluorescence analysis technique,with its special capability of detecting polycyclic aromatic hydrocarbons(PAHs) in crude oil,has been widely used in the field of oil logging.After being introduced into China from former Soviet Union in 1930s,the technique has experienced three development stages:qualitative,semi-quantitative and quantitative analysis stage,with significant improvements on its technical means. But there are still some defects in application of this technique.The measurement of emission spectrum is comparatively easy and fast,but with limited concentration range and lower accuracy.A new method based on synchronous fluorescence spectrum analysis of crude oil has been established by the Optics & Optoelectronics Laboratory of Ocean University of China,which can effectively solve the problem mentioned above,and meet all the need of oil logging on both accuracy and efficiency.But the extraction agents conventionally used nowadays are with high toxicity and relatively poor fluorescence property,they can hardly meet all the need of quantitative analysis.In order to solve this problem,in this thesis,some relative experimental investigations have been made to find an idea extraction agent with the purpose to improve the accuracy of fluorescence quantitative analysis.This thesis consists of three main parts and applies the research approach of experimental comparison.The first part makes introductions of relative contents which provide theoretical foundation,research thought,and experimental method of this thesis.Theoretical explanation and literature review are made first by means of introducing basic theories,relative fluorescence detection techniques,and development of fluorescence analysis method in petroleum exploration as well as usage of extraction agents in oil logging in history.Then an introduction about origin and characters of crude oil samples used in experiments,properties and parameter settings of instruments,data processing and 3D spectra formation is made. There were more than ten types of organic solvents used in the developing history of fluorescence oil logging,and they are chosen as research objects in this thesis. Comprehensive comparison experiment is made at two aspects of solubility and fluorescence property.Solutions of the same crude oil sample with concentration range from 10g/L to 10-4g/L were prepared using different types of extraction agents. Through the comparison experiments of emission spectrum and synchronous spectrum about fluorescence property of both the extraction agents and solutions, isopropanol is chosen as an idea extraction agent in fluorescence quantitative analysis.Then as an idea extraction agents,isopropanol is used to prepare solution of different crude oil samples with concentration range from 10g/L to 10-4g/L.Samples from different well districts or different well numbers and samples with similar physical characteristics were chosen to ensure the representativeness of the comparison experiment.It is found that the fluorescence spectra of various crude oil are obviously different,and these differences are not affected by the similarities of districts,burial time,geological conditions and physical characteristics.This means it's feasible to identify different kinds of crude oil by means of analyzing their fluorescence spectral with proper data processing method.These contents compose of main work in the second part of this thesis.At the last part of this thesis,summarizes of all the work are made and some possible future developments are brought forward to make certain improvements in data processing and feature extraction include new information extracting method, pattern recognition techniques and new achievements of chemometrics.With these improvements,the newly developed methods may become a useful means in petroleum logging.
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