Evaluation of the Efficiency of Additives on the Destabilization of Petroleum Emulsions

摘要

The demulsification process is extremely important in the petroleum industry because the natural formation of water-in-oil (w/o) emulsions hinders the performance and increases the cost of the production and processing of crude oil. Commercially produced polymers have been widely used as additives to destabilize these emulsions, among them block copolymers of poly(ethylene oxide) and poly(propylene oxide), or PEO-PPO block copolymers. This article reports the performance of a series of commercial demulsifiers based on silicone polyethers, containing PEO or PEO-PPO block copolymers in their chains. The stability of the w/o emulsions, with and without the additives, was evaluated by determining the water/oil interfacial tension, the compressibility of the films formed at these interfaces and the gravitational separation of oil and water by the bottle test. The results show that the addition of these additives reduced the interfacial tension of the systems, indicating the adsorption of their molecules at this interface. All the additives promoted the breakdown of the w/o emulsions, but those with higher molar masses and chains of PEO-PPO block copolymers were the most efficient.