PARAFFIN DEPOSITION IN OIL PRODUCTION - OIL COMPOSITION AND PARAFFIN INHIBITORS ACTIVITY

Several commercial paraffin inhibitors were evaluated with highly para ffinic crudes. Pour point depression was observed in some of the studi ed crudes in the presence of any product, while others showed insignif icant changes in this parameter. Crudes characterization was achieved with physico-chemical analysis (pour point, cloud point and API gravit y) and hydrocarbon analysis (thin layer chromatography with flame ioni zation detection, wax content, gel permeation chromatography and high temperature simulated distillation). A correlation between crude oil c omposition and paraffin inhibitors activity was found. The normal / cy clo+iso-paraffins ratio of the crudes that were not affected by the pa raffin inhibitors was found higher compared to the others. The molecul ar weight distribution of the crudes which responded to modifiers, sho wed a bimodal character and a concentration of components with more th an 24 carbon atoms lower than 39 % wt. On the other hand, the crudes i nsensitive to the action of the inhibitors displayed monomodal molecul ar weight distributions with larger contributions of heavy components (more than 52 % wt). Doping experiments supporting the former findings , permitted to asses the inefficiency of commercial paraffin inhibitor s for crudes rich in C24+ alkanes.