Methane hydrate formation and dissociation kinetics were investigated in seawater-saturated consolidated Ottawa sand-pack under sub-seafloor conditions to study the influence of effective pressure on formation and dissociation kinetics. To simulate a sub-seafloor environment, the pore-pressure was varied relative to confining pressure in successive experiments. Hydrate formation was achieved by...

This collaborative effort to compare the world’s leading gas hydrate reservoir simulators is designed primarily to exchange information and insight that will lead to the improvement in simulation capability of experimental and naturally occurring gas hydrate accumulations. The initial phase of the code comparison activity achieved the simulation of five problems of increasing complexity by five...

tivity phenomenon that is widely accepted as indicating the base of the gas-hydrate stability zone. The acoustic impedance difference between sediments invaded with gas hydrate above the BSR and sediments without gas hydrate, but commonly with free gas below, are accepted as the conditions that create this reflection. The relationship between BSRs and marine gas hydrate has become so well known...

The results of six high-precision constant energy molecular dynamics (MD) simulations initiated from methane-water systems equilibrated at 80 MPa and 250 K indicate that methane hydrates can nucleate via multiple pathways. Five trajectories nucleate to an amorphous solid. One trajectory nucleates to a structure-I hydrate template with long-range order which spans the simulation box across perio...

Hydrate formation is a phase transition which can occur during manufacturing processes involving water. This work considers the prevention of hydration of anhydrous olanzapine and hydrate conversions in the presence of water and polymers (polyethyleneglycol; hydroxypropylcellulose; polyvinylpyrrolidone) in forming pellets by wet extrusion and spheronisation. Anhydrous olanzapine was added to wa...

The effect of the concentration of kinetic hydrate inhibitors, polyvinylpyrrolidone (PVP), and polyvinylcaprolactam (PVCap) on the onset and growth of synthetic natural gas hydrates is investigated by measuring the hydrate onset time and gas consumption rate. Although the hydrate onset time is extended by increasing the concentration from 0.5 to 3.0 wt % for both PVP and PVCap, the growth rate ...

Methane hydrate nucleation and growth in porous model carbon materials illuminates the way towards the design of an optimized solid-based methane storage technology. High-pressure methane adsorption studies on pre-humidified carbons with well-defined and uniform porosity show that methane hydrate formation in confined nanospace can take place at relatively low pressures, even below 3 MPa CH4, d...

The kinetics of nucleation of one-component gas hydrates in aqueous solutions are analyzed. The size of the hydrate nucleus and the work for nucleus formation are determined as functions of the supersaturation Dm: Expressions for the stationary rate J of hydrate nucleation are derived. These expressions describe the JðDmÞ dependence for homogeneous nucleation and for heterogeneous nucleation at...

The investigation of surface tension is a very important task for gas hydrate studying. Surfactants can effectively reduce the surface tension, improve the gas storage capability of hydrate and increase the formation rate, shorten the induction time. The objective of this study were to obtain a better understanding of the role of surface tension on hydrate formation and build gas hydrate models...

Natural gas hydrates are solid hydrogen-bonded water crystals containing small molecular gases. The amount of natural gas stored as hydrates in permafrost and ocean sediments is twice that of all other fossil fuels combined. However, hydrate blockages also hinder oil/gas pipeline transportation, and, despite their huge potential as energy sources, our insufficient understanding of hydrates has ...