V/NI-RATIO IN MALTENE AND ASPHALTENE FRACTIONS OF CRUDE OILS FROM THE WEST VENEZUELAN BASIN - CORRELATION STUDIES

This study presents the contents of S, V and Ni in the maltene fraction (hydrocarbons plus resins) extracted from fifteen crude oils samples, belonging to the Mara and Mara Oeste fields of the Maracaibo basin, Venezuela. Results are discussed according to their implications in oil-oil correlation studies, and are compared with previous work where the same analytical parameters have been used for total oil and for its asphaltene fraction. Results obtained suggest that the V/Ni ratio may be used as a correlation parameter and as a genetic indicator when determined in any of the oil fraction, coupled with the results of the distribution of biomarkers. The absolute concentration of these elements may be used as indicators of alteration processes in the reservoir.