Gas hydrate model and free gas model are established, and two-phase theory (TPT) for numerical simulation of elastic wave velocity is adopted to investigate the unconsolidated deep-water sedimentary strata in Shenhu area, South China Sea. The relationships between compression wave (P wave) velocity and gas hydrate saturation, free gas saturation, and sediment porosity at site SH2 are studied, r...

An hybrid absorption-hydration method was adopted to recover C2H4 from C2H4/CH4 binary gas mixtures and the hydrate formation conditions of C2H4/CH4 mixtures was studied experimentally in diesel in water (w/o) emulsions. Span 20 at a concentration of 1.0 wt% in the aqueous phase was added to form water in diesel emulsions before hydrate formation and then hydrate in diesel slurry was separated ...

We study phase transitions of small two dimensional Lennard Jones drops via microcanonical molecular dynamics in a broad energy range. We found that the caloric curve can be extended to high energies to comprehend high evaporation rates and highly non-equilibrium phenomena such as multifragmentation. Multifragmentation appears as a constant temperature region in the caloric curve like the solid...

We show that if a holomorphic Hamiltonian system is holomorphically integrable in the non-commutative sense in a neighbourhood of a non-equilibrium phase curve which is located at a regular level of the first integrals, then the identity component of the differential Galois group of the variational equations along the phase curve is Abelian. Thus necessary conditions for the commutative and non...

The presence of dry friction in mechanical systems induces the existence of an equilibrium set, consisting of infinitely many equilibrium points. The local dynamics of the trajectories near an equilibrium set is investigated for systems with one frictional interface. In this case, the equilibrium set will be an interval of a curve in phase space. It is shown in this paper that local bifurcation...

Gas hydrate blockage in pipelines during offshore production becomes a major problem with increasing water depth. In this work, a series of experiments on gas hydrate formation in a flow loop was performed with low flow rates of 0.33, 0.66, and 0.88 m/s; the effects of the initial subcooling, flow rate, pressure, and morphology were investigated for methane hydrate formation in the flow loop. T...

Recent advances in the molecular dynamics simulations of spontaneous nucleation and growth of methane hydrate show that an amorphous phase of the hydrate is first reached. However, the amorphous hydrate has not been well described, due to the insufficient identification of cage structures. Here, we develop a method, called "face-saturated incomplete cage analysis", which can identify all face-s...

Clathrate hydrates are crystalline compounds composed of hydrogen-bonded water molecules that form polyhedral cavities and trap small guest molecules such as methane, carbon dioxide, cyclopentane (CP), and tetrahydrofuran (THF). Understanding the formation and dissociation of clathrate hydrates is of significant importance to addressing some global challenges such as greenhouse gas mitigation a...

Stability condition is of critical importance for methane hydrate exploitation, transportation, and reserves. This study measured the stability conditions in fine-grained sediment with different dry densities (ρd = 1.40, 1.50 1.60 g/cm3) various initial water saturations by multi-step heating method. The experimental result showed that formation required lower temperature and/or higher pressure...