THE EFFECTS OF FLUID-FLOW THROUGH POROUS-MEDIA ON THE DISTRIBUTION OF ORGANIC-COMPOUNDS IN A SYNTHETIC CRUDE-OIL

In a controlled laboratory simulation of petroleum migration, a 17-component mixture containing hydrocarbons and heterocyclic compounds was flowed through restricted mineral phases using a modified liquid chromatographic (LC) apparatus. The solid phases, tested in wet and dry conditions, consisted of quartz, quartz/montmorillonite and a reservoir rock sample containing quartz and clay minerals. The redistribution of hydrocarbon and other compounds along the migration paths was determined for replicate LC simulation runs of each solid phase and quantified using gas chromatographic (GC) analysis against an external standard. Liquid/solid chromatographic interactions enrich the earliest eluting fractions in saturated compounds and in lower molecular-weight compounds and, conversely, increase the concentrations of more polar compounds in the fraction which remain on the solid phases. The changes in compound composition are reproducible and verifiable outside the margin of error, despite the low levels of solid phase activity and short migration distances (15 cm) employed in this study. The results indicate specific parameters which may identify migration phenomena in the subsurface, e.g. trends in the quinoline concentration of a crude oil and trends in the ratio of a crude oil's concentration of n-C-16/dibenzothiophene or n-C-16/2-methylphenanthrene.