Outlook on the Role of Natural Surfactants on Emulsion Stability and Gas Hydrate Antiagglomeration in Crude Oil Systems

Gas hydrates constitute a major flow assurance issue in the transportation of oil and gas from the reservoir to the point of sale via pipelines. They can reduce or arrest the hydrocarbon production in a short period of time. Gas hydrate mitigation strategies involve the application of surfactant-like molecules able to prevent the agglomeration of hydrate particles and thus reducing their tendency to plug the flowlines. Some crude oils, commonly referred to as nonplugging oils, show a natural hydrate antiagglomerant tendency. This property has been related to crude fractions, such as asphaltenes and acids that naturally behave as surfactants. Given that these natural surfactants play a key role in the stabilization of water-in-crude oil emulsions, it has been practically unavoidable to consider hydrate antiagglomeration as a phenomenon linked to the stability of crude oil emulsions. Although hydrate natural antiagglomeration is a result of complex mechanisms involving crude oil composition, physicochemical conditions of the system, and fluid dynamics, the concentration and interfacial activity of natural surfactants are paramount in understanding the whole antiagglomeration process.