THE PROPERTIES OF MICROSPECTROFLUORIMETRY AND THERMAL MATURITY ASSESSMENT OF INDIVIDUAL OIL INCLUSIONS

摘要

The oil inclusions are called “minor reservoirs” which were trapped in the imperfections of diageneticrnminerals or healed cracks, and carry abundant information of hydrocarbon migration and accumulation. It is,rntherefore, that the properties of microspectrofluorimetric analysis for individual oil inclusions become one ofrnthe powerful tools of complicated hydrocarbon migration and accumulation with multi-sources and multistages.rnOn the basis of carding the mechanism of crude oils/oil inclusions emission fluorescence under UVrnexcitation (365nm), the microspectrofluorimetric analysis for single oil inclusion integrated with structuredrnlight illumination microscopic imaging technique (SLIMIT) has been employed in this research to insight therninfluence factors of microspectrofluorimetric properties for the same oil inclusion assemblage (OIA). Thernresults show that although both the chemical fractionation in the oil migration and accumulation and trappingrnfractionation during oil inclusion trapped are imposed on the properties of emission fluorescence of OIA,rnsuch as the peak wavelength altered within a small range (<20nm), the thermal maturities are the mainrncontrolling factor for the properties of OIA fluorescence. Consequently, it is essential to consider therninfluence factors, such as selective polar adsorption, oil cracking within inclusion and leakage of oilrninclusion, during the thermal maturity assessment of individual oil inclusions. In practice, the best way is tornuse SLIMIT to recognize the altered oil inclusions first and then exclude them in analysis, the fluorescentrnproperties of the rest oil inclusions are suitable for thermal maturity assessment, hydrocarbon chargingrnevents determination and tracing of hydrocarbon migration pathway.