DEMULSIFIERS FOR CRUDE OIL BASED ON CONTROLLED MOLECULAR WEIGHT ALKYLACRYLIC-AMINOACRYLIC-CARBOXYACRYLIC RANDOM TERPOLYMERS.

Abstract

One of the major challenges currently facing the petroleum industry is the presence of large quantities of water and salts in oil streams, which cannot be efficiently removed by conventional dehydrating polymers. Furthermore, acid well stimulation operations cause the chemical degradation of demulsifiers such as polyethers and phenolic resins, drastically reducing their effectiveness in removing water and salts. Based on this, terpolymers have been developed that are combinations of a monomer derived from an alkyl acrylate, one derived from an aminoalkyl acrylate, and another derived from a carboxyalkyl acrylate. These terpolymers are synthesized by semi-continuous emulsion polymerization (under monomer-deficient conditions), which ensures both the homogeneity of the different chains and the randomness of the monomer distribution.Solutions of these random terpolymers have shown similar or superior efficiency to combinations (formulations) of two or three polyether block polymers when applied to light or heavy crude oils. Thus, alkylacrylic-aminoacrylic-carboxyacrylic terpolymers exhibit excellent performance as initiators of water-in-crude oil emulsion breakdown, coalescers of water droplets, and clarifiers of the remaining aqueous phase. Additionally, it is important to note that these novel alkylacrylic-aminoacrylic-carboxyacrylic terpolymers demonstrate a superior clarifying capacity for water extracted from crude oil compared to acrylic biopolymers [19], vinyl acrylics [12], and polyethers reported in the literature. The dehydrating capacity of these terpolymers is superior to that of commercially available polyethers and resins.In contrast to commercially available polyethers and dehydrating resins used as demulsifiers, the chemical structure of these new acrylic terpolymers gives them resistance to degradation induced by abrupt pH changes during acid well stimulation operations.

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