The combustion characteristics of both pure propane hydrates and the mixtures of hydrates and quartz sands were investigated by combustion experiments. The flame propagation, flame appearance, burning time and temperature in different hydrate layers were studied. For pure propane hydrate combustion, the initial flame falls in the “premixed” category. The flame propagates very rapidly, mainly as...

This paper reports an experimental study of the formation of a mixed O(3)+ O(2)+ CO(2) hydrate and its frozen storage under atmospheric pressure, which aimed to establish a hydrate-based technology for preserving ozone (O(3)), a chemically unstable substance, for various industrial, medical and consumer uses. By improving the experimental technique that we recently devised for forming an O(3)+ ...

Gas hydrates dominated by methane naturally occur in deep marine sediment along continental margins. These compounds form in pore space between the seafloor and a sub-bottom depth where appropriate stability conditions prevail. However, the amount and distribution of gas hydrate within this zone, and free gas below, can vary significantly at different locations. To understand this variability, ...

Vast quantities of natural gas are held in hydrate form in geologic reservoirs in sub-oceanic sediments and arctic permafrost zones (KVENVOLDEN, 1988; SLOAN, 1998), where conditions of high pressure and low temperature are within the hydrate stability region. In 1995, the U.S. Geological Survey (USGS) conducted a study to assess the quantity of natural gas hydrate resources in the United States...

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 ...

[1] The mechanical behavior of hydrate-bearing sediments subjected to large strains has relevance for the stability of the seafloor and submarine slopes, drilling and coring operations, and the analysis of certain small-strain properties of these sediments (for example, seismic velocities). This study reports on the results of comprehensive axial compression triaxial tests conducted at up to 1 ...

The structures and the guest-host distributions of iso-propylamine (i-PA) and n-propylamine (n-PA) hydrates with hydrogen as a secondary guest were identified by powder X-ray diffraction and Raman spectroscopic analysis. The structure of 11.1 mol% i-PA + H2 hydrate was identified to be hexagonal (space group P63/mmc) with a few unindexed diffraction peaks, while 5.6 mol% i-PA + H2 hydrate had a...

Natural gas hydrates (NGH) are potential energy resource and distributed in unconsolidated marine sediments. CH4–CO2 swapping combined with depressurization is a promising method for simultaneously enhancing CH4 recovery CO2 storage NGH. This was previously studied on CH4/CO2 mixed consolidated sediments but no such studies available In this study, we investigated dissociation characteristics o...

We investigated structural changes, phase diagram, and vibrational properties of hydrogen hydrate in filled-ice phase C(2) by using first principles molecular dynamics simulation. It was found that the experimentally reported "cubic" structure is unstable at low temperature and/or high pressure: The "cubic" structure reflects the symmetry at high (room) temperature where the hydrogen bond netwo...

Interfacial interactions between liquid-solid and solid-solid phases/surfaces are of fundamental importance to the formation of hydrate deposits in oil and gas pipelines. This work establishes the effect of five categories of physical and chemical modification to steel on clathrate hydrate adhesive force: oleamide, graphite, citric acid ester, nonanedithiol, and Rain-X anti-wetting agent. Hydra...