Advances in Analytical Technologies for Correlation of All Hydrocarbon Fluids, Oil Mixtures and Extracts
Classical geochemical technology developed decades ago retains value, but in most cases, applications simply retrace previous conclusions and do not open new opportunities. New technologies that deliver the resolving power necessary to distinguish hydrocarbon sources in greater detail and delineate co-sourced petroleum mixtures open new vistas in basin modeling. Here we reveal novel compound specific isotope analysis (CSIA) parameters to accomplish those goals. In order to perform CSIA the targeted compound classes must first be isolated from the petroleum. CSIAs of steranes, hopanes, C12-C40 isoprenoids and C7-C30+ alkanes, terrestrial terpanes (e.g. bicadinane and oleanane), naphthalenes, phenanthrenes and diamondoids are illustrated and examples from worldwide applications to perform source-differentiation are depicted. Laboratory mixtures from different end-member oils from Venezuela, Colombia and the US Gulf of Mexico, respectively, were prepared. Analyses of these mixtures show the power of those new methods for (1) recognition of mixes, (2) determination of all sources, and (3) determination of the relative input from each source. Methods to utilize asphaltenes for biodegraded-oil correlation are also revealed. Asphaltenes preserve original biomarkers and alkanes. Those compounds can be generated by hydrous pyrolysis and used for correlation. While fingerprints of these generated compounds might not match related non-biodegraded oil, the generated biomarkers and alkanes retain isotopic signatures from the kerogen and can be used for correlation by using CSIA methods. Diamondoids are a universal compound class for correlation. With a few exceptions, diamondoids are recalcitrant or inert to alteration by biodegradation and can be used to correlate severely biodegraded oil. They can be sequestered even from severely biodegraded oil or thermally altered condensate and used for correlation with any other petroleum liquids or extracts both by CSIA-D and by fingerprints of large diamondoid molecules (tria-, tetra-, pentamantanes, etc.), termed quantitative extended diamondoid analysis (QEDA).
AAPG Datapages/Search and Discovery Article #90189 © 2014 AAPG Annual Convention and Exhibition, Houston, Texas, USA, April 6–9, 2014