Peer-Reviewed Journal Details
Mandatory Fields
Ryder, A.G.; Przyjalgowski, M.A.; Feely, M.; Szczupak, B.; Glynn, T.J.;
Applied Spectroscopy
Time-Resolved Fluorescence Microspectroscopy for Characterizing Crude Oils in Bulk and Hydrocarbon- Bearing Fluid Inclusions
Optional Fields
fluorescence lifetime petroleum oils APT gravity alkane aromatic asphaltene sulfur polar
Time-resolved fluorescence data was collected from a series of 23 bulk crude petroleum oils and six microscopic hydrocarbon-bearing fluid inclusions (HCFI). The data was collected using a diode laser fluorescence lifetime microscope (DLFLM) over the 460700 nm spectral range using a 405 nm excitation source. The correlation between intensity averaged lifetimes ( ) and chemical and physical t parameters was examined with a view to developing a quantitative model for predicting the gross chemical composition of hydrocarbon liquids trapped in HCFI. It was found that is nonlinearly t correlated with the measured polar and corrected alkane concentrations and that oils can be classified on this basis. However, these correlations all show a large degree of scatter, preventing accurate quantitative prediction of gross chemical composition of the oils. Other parameters such as API gravity and asphaltene, aromatic, and sulfur concentrations do not correlate well with measure- t ments. Individual HCFI were analyzed using the DLFLM, and time resolved fluorescence measurements were compared with data t from the bulk oils. This enabled the fluid within the inclusions to be classified as either low alkane/high polar or high alkane/low polar. Within the high alkane/low polar group, it was possible to clearly discriminate HCFI from different locales and to see differences in the trapped hydrocarbon fluids from a single geological source. This methodology offers an alternative method for classifying the hydrocarbon content of HCFI and observing small variations in the trapped fluid composition that is less sensitive to fluctuations in the measurement method than fluorescence intensity based methods.
Grant Details
This work was supported by funding from the National Centre for Biomedical Engineering Science in NUI-Galway as part of the Higher Education Authority Programme for Research in Third Level Institutions, from Bank Zachodni/Allied Irish Bank in the form of a fellowship MAP, from Science Foundation Ireland under Grant no. [02/IN.1/M231], and in part by an Enterprise Ireland Research Innovation Fund Grant (IF/2001/061).
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