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

This study presents the contents of S, V and Ni in the maltene fractio n (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 oi l-oil correlation studies, and are compared with previous work where t he 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 de termined in any of the oil fraction, coupled with the results of the d istribution of biomarkers. The absolute concentration of these element s may be used as indicators of alteration processes in the reservoir.