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

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.