[1] We have made direct comparisons of the dissolution and rise rates of methane and argon bubbles experimentally released in the ocean at depths from 440 to 830 m. The bubbles were injected from the ROV Ventana into a box open at the top and the bottom, and imaged by HDTV while in free motion. The vehicle was piloted upwards at the rise rate of the bubbles. Methane and argon show closely simil...

The LArge Reservoir Simulator (LARS) was developed to investigate various processes during gas hydrate formation and dissociation under simulated in situ conditions of relatively high pressure and low temperature (close to natural conditions). To monitor the spatial hydrate distribution during hydrate formation and the mobility of the free gas phase generated during hydrate dissociation, a cyli...

• CH 4 hydrate formation rates were measured in varied temperatures, pressures and flow regimes. Five growth regimes identified with physical mechanisms proposed. The affect on the integrity of growing films rates. Hydrate exponentially increase chemical potential driving forces. Semi-empirical equations derived to describe this exponential relationship. To underpin increasing interest practica...

[1] Log and core data document gas saturations as high as 90% in a coarse-grained turbidite sequence beneath the gas hydrate stability zone (GHSZ) at south Hydrate Ridge, in the Cascadia accretionary complex. The geometry of this gassaturated bed is defined by a strong, negative-polarity reflection in 3D seismic data. Because of the gas buoyancy, gas pressure equals or exceeds the overburden st...

At present, the formation mechanism of gas hydrate (hereinafter referred to as hydrate) plugging in wellbore during deepwater drilling is not clear, so there are problems such overuse inhibitors and low utilization efficiency inhibitors. Therefore, view risk under different working conditions drilling, research was carried out on area deposition plugging. Taking an atmospheric well South China ...

Long offsets and subsea tie-backs are becoming attractive scenarios for exploration and production of offshore hydrocarbon resources. Flow assurance associated with these field development scenarios is critical. As offshore oil and gas production pushes into deeper water, the risk of hydrate plugging of pipelines and flowlines continues to grow, as does the cost of remediating any such plugs. C...

Concerns about the potential effects of rising carbon dioxide levels in the atmosphere have stimulated interest in a number of carbon dioxide sequestration studies. One suggestion is the sequestration of carbon dioxide as clathrate hydrates by injection of carbon dioxide into methane hydrate. Energy-supply research estimates indicate that natural gas hydrates in arctic and sub-seafloor formatio...

The small hydrate concept (SHC) was proposed to predict the generated excess pore water pressure due to dissociation of gas hydrate within sandy soils. This concept was then used to calculate excess pore water pressure in the Storegga slide of which gas hydrate dissociation may have contributed. Since the excess pore water pressure calculated by the SHC resulted in the considerable loss of stif...