FT-IR measurements of petroleum fluid inclusions: methane, n-alkanes and carbon dioxide quantitative analysis
| Autor: | Régis Thiéry, Stéphane Teinturier, Jacques Pironon, M. Ayt Ougougdal, F. Walgenwitz, Georges Beaudoin |
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| Rok vydání: | 2001 |
| Předmět: | |
| Zdroj: | Geofluids. 1:2-10 |
| ISSN: | 1468-8123 1468-8115 |
| DOI: | 10.1046/j.1468-8123.2001.11002.x |
| Popis: | A recent advancement in petroleum geochemistry is to model fossil oil composition using microthermometric and volumetric data acquired from individual fluid inclusion analysis. Fourier transform infrared (FT-IR) microspectroscopy can record compositional information related to gas (CH4 and CO2) and alkane contents of petroleum inclusions. In this study, a quantitative procedure for FT-IR microspectrometry has been developed to obtain, from individual fluid inclusions, mol percentage concentrations of methane, alkanes and carbon dioxide as constraints to thermodynamic modelling. A petroleum inclusion in a sample from the Quebec City Promontory nappe area was used as standard to record a reference spectrum of methane. The analytical procedure is based on the measurement of CH4/alkane and CH4/CO2 band area ratios. CH4/alkane infrared band area ratio is obtained after spectral subtraction of the reference methane spectrum. This area ratio, affected by absolute absorption intensities of methane, methyl and methylene, provides a molar CH4/alkane ratio. Methyl/methylene ratio (CH2/CH3) ratio is obtained following procedures established in previous work. CO2/CH4 concentration ratio is estimated from relative absolute absorption intensities. Application to natural inclusions from different environments shows good correlation between FT-IR quantification and PIT (petroleum inclusion thermodynamic) modelling. |
| Databáze: | OpenAIRE |
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