Investigation on Hydrate Formation and Growth Characteristics in Dissolved Asphaltene-Containing Water-In-Oil Emulsion.

Abstract

Clarifying the effect of asphaltene on hydrate formation and growth is of great significance to the operation safety in deepwater petroleum fields. To investigate the influence of low-concentration dissolved asphaltenes on the formation kinetics and growth process of hydrates in water-in-oil emulsions, experiments with asphaltene concentrations ranging from 50 to 1000 ppm were carried out using a high-pressure visual reactor. At a low concentration, the adsorption of asphaltene monomers on the oil-water interface or nanoaggregates in the bulk barely affected the nucleation of hydrate and the induction time of hydrate formation. However, it would hinder the microscopic mass transfer process and heat transfer process between gas molecules and then mitigate the initial rate of hydrate formation. Therefore, the dissolved asphaltenes could not be used as antiagglomerants (AAs) to efficiently inhibit the aggregation of hydrate particles at low concentrations under our experimental conditions, causing extensive hydrate agglomeration and deposition in the reactor.