Fluorescence micro-spectrometry of synthetic and natural hydrocarbon fluid inclusions: crude oil chemistry,density and application to petroleum migration |
| |
| Institution: | 1. School of Geosciences, China University of Petroleum (East China), Qingdao 266580, China;2. Research Institute of Unconventional Oil & Gas and Renewable Energy, China University of Petroleum (East China), Qingdao 266580, China;3. Energy and Geoscience Institute (EGI), University of Utah, Salt Lake City, UT 84108, USA;1. Department of Geography and Geology, University of Turku, FIN-20014 Turku, Finland;2. Geological Survey of Finland (GTK), P.O. Box 96, FI-02151 Espoo, Finland;1. Department of Earth and Environmental Sciences, University of Iowa, Iowa City, IA 52242, USA;2. Evo-Eco-Paleo, UMR 8198 du CNRS, Université Lille 1, Villeneuve d''Ascq 59655, France;3. Department of Geology and Soil Sciences, Ghent University, Ghent 9000, Belgium;4. Kansas Geological Survey, University of Kansas, Lawrence, KS 66047, USA |
| |
| Abstract: | The fluorescence spectra of crude oils, synthesized as hydrocarbon fluid inclusions (hcfi) in NaCI crystals, have been recorded and correlated with crude oil chemical analysis. The crude oils represent a wide range in total hydrocarbons, saturate and aromatic fractions, and resin-asphaltene concentration. The fluorescence properties (Lambda max and Q) of the hydrocarbon fluid inclusions display a systematic red shift to longer wavelengths from 440 nm to 595 nm with increasing aromatic content and increasing concentration of NSO-bearing compounds. A positive correlation also exists between Lmax-Q and the thermal maturity parameters nC17/pristane and nC18/phytane. First order linear regression equations provide a method for constraining the chemical composition of natural hydrocarbon fluid inclusions. Lmax and Q correlate positively with oil density (°API), providing for an indirect method of estimating the API of a natural hydrocarbon fluid inclusion assemblage. Fluorescence spectra of non-biodegraded crude oils from the Upper Devonian Birdbear Formation, Saskatchewan, Canada, have been correlated with regionally widespread hcfi within carbonate carrier beds and reservoir rocks of the same formation. The two most dominant types of hcfi spectra match well with the fluorescence spectra from crude oils within the Birdbear Formation. A third, less common population of very-blue fluorescing hcfi (Lmax=415440 nm, Q ≤ 0.10) also occur within fractures, intercrystalfne cements or in fossil overgrowths. The Lmax-Q-API-chemical correlations establised for the synthetic hcfi suggests that the °API of these inclusions is probably > 45° and the saturate/aromatic ratio ranges from 3.2 to 5.1. Spectra from hcfi within quartz overgrowths and cements, fractures and carbonate cements from sandstone reservoirs in the Jeanne d'Arc Basin offshore Newfoundland, compared with fluorescence spectra of crude oils suggests that some of the reservoirs may have been filled by a relatively low maturity oil and then a higher maturity oil. This is reflected in the intermediate spectra of the crude oils relative to the spectra of two separate hcfi events. Other reservoirs appear to have been charged with a relatively high gravity oil which was later biodegraded. This is marked by a blue region spectra for the hcfi compared with a red-shifted spectra for the crude oil (°API = 19). The API of the original unaltered oil which charged the reservoir is estimated to be between 32 and 38° using the Lmax-Q-API relationship established for the synthetic hcfi. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
