In this work we investigated the behavior of methane hydrates dispersed in crude oils from different fields at temperatures below 0°C. In case of crude oil emulsion the size of water droplets is in the range of 50÷100μm. The size of hydrate particles formed from droplets is the same. The self-preservation is not expected in this field. However, the self-preservation of hydrates with the size of...

[1] We develop a theory that relates gas hydrate saturation in marine sediments to the depth of the sulfate‐ methane transition (SMT) zone below the seafloor using steady state, analytical expressions. These expressions are valid for systems in which all methane transported into the gas hydrate stability zone (GHSZ) comes from deeper external sources (i.e., advective systems). This advective co...

The presence of structure H (sH) methane hydrate in natural environments, in addition to the well-known structure-I (sI) and II (sII) hydrates, has recently been documented. Methane in the presence of condensates (C5-C7) forms sH hydrate at lower pressure than the sI hydrate. Thus, the occurrence of sH methane hydrate is likely to have both beneficial and negative practical implications. On the...

Hydrate-based technologies have excellent application potential in gas separation, storage, transportation, and seawater desalination, etc. However, the long induction time slow formation rate are critical factors affecting of hydrate-based technologies. Micro-nano bubbles (MNBs) can dramatically increase hydrates owing to their advantages providing more nucleation sites, enhancing mass transfe...

Ocean storage of CO2 was proposed by Marchetti as one of greenhouse gas control technologies, where CO2 is captured from flue gas of fossil fuels and injected into deep seafloor below the depth of 3500m to be sequestered from the atmosphere as shown in Fig. 1. In the last decade of the twenties century, there was a great progress in study on the ocean storage. Aya and his colleagues and Nishika...

Hydrate-based Carbon dioxide (CO2) separation was widely concerned because of its simple process and low energy consumption. Mechanical stirring could promote gas-liquid-hydrate three-phase contact hydrate formation but consumed lots energy. Therefore, it necessary to develop more efficient technologies. Nickel foam (Ni–F) is an excellent hydrogen (H2) storage material with properties porous st...

Antifreeze proteins (AFPs) prevent ice growth by binding to a specific ice plane. Some AFPs have been found to inhibit the formation of gas hydrates which are a serious safety and operational challenge for the oil and gas industry. Molecular dynamics simulations are used to determine the mechanism of action of the winter flounder AFP (wf-AFP) in inhibiting methane hydrate growth. The wf-AFP ads...

The main purpose of this study is to investigate the production behaviors of gas hydrate at site DK-2 in the Qilian Mountain permafrost using the novel five-spot well (5S) system by means of numerical simulation. The whole system is composed of several identical units, and each single unit consists of one injection well and four production wells. All the wells are placed horizontally in the hyd...

A number of laboratory experiments have investigated the rates and mechanisms of hydrate formation in coarse-grain porous media. They have shown the importance of initial water saturation and salinity on forming methane hydrates in mostly excess gas systems. Many of these experiments were conducted in a sample holder fitted within a MRI instrument that allowed for a unique method of monitoring ...

Gas hydrates were first discovered by Sir HumphryDavy in 1810 [1]. Clathratehydrates are crystalline compounds, formed by the smaller molecules (guest), entrapped within the cavities of a rigid “cage-like” lattice of water molecules (host) at low temperature (typically less than 300K) and high pressure (typically more than 0.6MPa) conditions [2]. The small molecules of gasses, such as methane (...