Gas hydrate formation probability distributions: Induction times, rates of nucleation and growth

Experimental study of growth kinetics of CO2 hydrates and multiphase flow properties of slurries in high pressure flow systems

“…Different researchers have proposed different denitions of hydrate induction time based on different experimental systems. [30][31][32][33][34][35] In this work, induction time is described from the macroscopic aspect, including critical nuclei stage and visible crystal stage. In other words, the induction time is determined by a start point and an end point that is easy to observe and characterized by the large amount of hydrate formation.…”

“…Therefore, through sensitivity analysis, the system water content has the most signicant inuence on the induction period of CO 2 hydrate formation, liquid loading take the second place, mass ow rate next, and initial pressure on induction time the weakest. Moreover, establishing an induction time model for oil-water systems based on classic nucleation theories 34,35 will be the focus of next step work. According to the similarity criterion in uid mechanics, it is supposed that the ow and plugging phenomenon as well as mechanisms in the ow loop will have similarities with the industrial pipelines.…”

Hydrate nucleation and growth on water droplets acoustically-levitated in high-pressure natural gas

“…Recently, May and co-workers (16,17) reported robust measurements of gas hydrate formation probability distributions using an improved technique based on a highpressure stirred automated lag time apparatus (HPS-ALTA), and compared their results with other experimental studies and the predictions of classical nucleation theory (CNT). (11) They found that careful nucleation rate measurements reported in the literature were broadly consistent, particularly those determined in well-mixed systems where the agreement was within a factor of three.…”

“…where J is a nucleation rate specific to the system sub-cooling T = Teqbm-T, and where Teqbm is the hydrate equilibrium temperature at p. This distribution is indeed observed if sufficient numbers of formation events are measured, particularly if the experimental system is well-mixed and devoid of mass transfer limitations. (16,(19)(20)(21) The nucleation rate scales with system size, and in principle should be proportional to either volume, V, in the case of homogenous nucleation (difficult to achieve in practice (22)), or to the area, A, of the interface upon which nucleation is occurring. However, a key limitation identified by Metaxas et al (16) upon analysing multiple hydrate formation experiments was the inability to identify the specific interface at which the nucleation was occurring.…”

Molecular properties of interfaces relevant for clathrate hydrate agglomeration

“…When natural gas and water molecules are both present at high pressure and low temperature, hydrates might form. The formation of hydrate plugs involves several processes, including hydrate nucleation, growth and agglomeration [12]. Large hydrate plugs could block pipelines and subsea flowlines, causing safety, environmental and economic threats [6].…”