Discussion of the State-of-the-Art Instrumentation in Petroleum Geochemistry

SENTFLE, J. T., E. TEGELAAR, E. JORDAN, and C. LANDIS, ARCO Oil and Gas Company, Plano, TX

In reviewing the development of analytical approaches of the last two decades, it is apparent that significant effort has been directed toward high resolution methods characterizing very small fractions of sedimentary organic matter. This is exemplified by the development of gas chromatography-isotope ratio mass spectrometry. On-line combustion, coupled with gas chromatography and isotope ratio mass spectrometry (GC-C-IRMS), allows the organic geochemist to collect more data from a single sample than has been available previously. Carbon isotope ratio data can be gathered on individual compounds in a saturate fraction or a whole oil, allowing the utilization of subtle relationships involving alkanes, isoprenoids, biomarkers, or other compounds in the investigation of genetic relations ips, maturation, migration, biodegradation, or correlations. The future of this technology includes the coupling of GC-C-IRMS with pyrolysis, or the development of on-line catalysis for the analysis of H/D ratios or nitrogen isotope ratios.

In addition to high resolution, data intensive characterization of smaller amounts of material, we envision that efforts will be focused upon development of methods for molecular characterization of greater fractions of the sedimentary organic matte, especially the complex high molecular weight fractions such as kerogens and asphaltenes. Potential areas of development include: (1) improved methods for the isolation of kerogens, (2) development of rapid kerogen characterization methods describing precursor-product relationships, (3) determination of kerogen heterogeneity by integration of microscopical and chemical techniques such as laser pyrolysis-GC-MS, (4) kerogen distribution in sediments, and (5) description of the maturation characteristics of kerogens emphasizing the product ge eration and evolution during catagenesis.

AAPG Search and Discovery Article #91004 © 1991 AAPG Annual Convention Dallas, Texas, April 7-10, 1991 (2009)