WATER/CRUDE OIL REMOVERS BASED ON ALKYLACRYLIC-CARBOXYALKYLACRYLIC RANDOM COPOLYMERS OF CONTROLLED MOLECULAR MASS

Nowadays, one of the major problems of the oil industry is the presence of large amounts of water and salts, which can not be efficiently removed by conventional dehydrating polymers. In addition, the acid stimulation operations of petroleum wells cause the chemical degradation of demulsifiers such as polyethers and phenolic resins, reducing drastically their efficiency as water and salt removers. Based on aforementioned, a series of new copolymers has been developed; these copolymers are combinations of an alkyl acrylate and a carboxyalkyl acrylate. These copolymers are synthesized by semi-continuous emulsion polymerization (under starved feed conditions), which ensures both the homogeneity of the different chains as well as the randomness of the monomers distribution. The solutions of one of these random copolymers have shown an efficiency similar or superior to combinations of two or three block copolymers (formulations), when they are applied in light or heavy crude oils. The acrylic-carboxyacrylic copolymers show good performance as water/oil emulsion breaker initiators, water droplet coalescers and clarifiers of the remaining aqueous phase. In addition, it is important to remark that these novel acrylic-carboxyacrylic copolymers show a higher clarification capacity in comparison with acrylic copolymers [19], vinyl acrylics [12] and polyethers. Dehydrating capacity of acrylic-carboxyacrylic copolymers is higher than polyethers and resins available in the market. Besides, unlike the commercial polyethers or resins, the chemical structure of the acrylic-carboxyacrylic copolymers are resistant to chemical degradation induced by abrupt changes in pH, when acid stimulation is carried out in wells.