Estudo do desempenho de aditivos orgânicos na inibição da precipitação de asfaltenos em petróleos de campos brasileiros

Abstract

The growing demand non-conventional oils has increasingly stimulated the study of the heavy fractions that make up this characteristic type of oil. Asphaltenes, substances of high molecular mass, with complex molecular structure, are stabilized by resins in the crude oil. Currently, they represent a source of problems in the industry since transport and processing operations, asphaltene molecules tend to aggregate, encrusting tubing, reducing its useful diameter, clogging equipment and generating high operational costs to correct the consequences caused by its precipitation due to variations in pressure, composition and temperature. A method most commonly employed to minimize this problem is the use of chemical additives in petroleum in order to retard or reduce the deposition process of these compounds in the petroleum production steps. In this work, the precipitation start point (onset) using n-heptane as the precipitating solvent in a concentration range of 30 to 90% (w/w) solvent was determined experimentally by gravimetric analysis. Crude oil was characterized by SARA fractionation (Saturated, Resin, Aromatic, Asphaltenes) using the DBR methodology. Ten organic additives were tested at a concentration of 1000 ppm in the oil with the objective of evaluating their efficiency in inhibiting the precipitation of asphaltene compounds. Four of these additives showed good inhibition potential: eugenol, salicylic acid, aniline and floroglucinol.