Viscosity, surface tension, and other physical-chemical characteristics of three crude oils arising from Chicontepec, Mexico

Three dead crude oil samples, arising from Chicontepec, Veracruz (Mexico), were characterized in terms of water content; sediment volume; the fraction of insoluble components in pentane; the fraction of saturated, polar, and aromatic compounds; and the acid and base numbers. In addition, the API density, viscosity at various temperatures, and surface tension were measured for each crude. At the end, some correlations between oil composition and surface properties and viscosity are presented. Viscosity and surface tension of these samples are correlated with the fraction of n-pentane insoluble components (asphaltenes) and inversely correlated with the fraction of aromatic compounds. The acid components in the crude oils are correlated with surface tension while the basic components are negatively correlated with it. Finally the base number is correlated with viscosity.