(1) Hydrate nucleation stochasticit

(1) Hydrate nucleation stochasticity was studied in wax-free andwaxy w/o emulsions, which indicated that log-normal distribution could well fit the probability density histogram of CP hydratecritical time. The logarithmic mean values of CP hydrate criticaltime decreased with the increasing water cut but increased withthe increasing wax content in w/o emulsions.(2) Semi-empirical models were proposed to describe the inhibitioneffect of wax crystals on CP hydrate nucleation kinetics considering the mass transfer based on the Freundlich and Langmuiradsorption functions, respectively. The relative deviations between the statistical mean values and the predicted values forboth prediction models are within 10.0%, and the maximum andthe minimum deviation are 7.0% and 0.4% separately. Theaverage relative deviations between the calculated and experimental critical time are 4.19% and 2.19% for the two models. It ismore perfect to use Langmuir adsorption function to describe theeffect of wax crystals on the mass transfer limitation of the oil–water interface.(3) The increasing rate of CP hydrate slurry shows the two-stagecharacteristics in wax-free w/o emulsions, while four stagescould be clearly observed in waxy w/o emulsions. The maximum values of the viscosity rate and calculated hydrate effective volume fraction decreased with increasing wax content. Hydrategrowth time was gradually extended with wax content increased.(4) The measured yield stress and yield strain increased with theincreasing wax content at different water cuts, which is associated with the couple effect of capillary bridge between hydrateparticles, spatial network of wax crystals and water droplet coalescence. The yield stress increased significantly when theannealing time increased from 2 h to 4 h. Compared to theannealing time, the influence of stress ramp rate on the yieldstress was not notable. More effects are required to reveal themechanism of the yield properties of waxy hydrate slurry.