We report the results of systematic investigations of the influence of thermal history and other factors on crystallization of a model clathrate hydrate (cyclopentane hydrate) studied as water-in-oil and oil-in-water emulsions to remove the nucleation influence of substrates other than ice and hydrates. Hydrate and ice seem to form simultaneously under the conditions of these experiments, with ...

Neutron diffraction runs and gas-consumption experiments based on pressure-volume-temperature measurements are conducted to study the kinetics of methane hydrate formation from hydrogenated and deuterated ice powder samples in the temperature range of 245-270 K up to high degrees of transformation. An improved theory of the hydrate growth in a polydisperse ensemble of randomly packed ice sphere...

Blockage of pipelines by formation and accumulation of clathrate hydrates of natural gases (also called gas hydrates) can compromise project safety and economics in oil and gas operations, particularly at high pressures and low temperatures such as those found in subsea or arctic environments. Cyclopentane (CyC5) hydrate has attracted interest as a model system for studying natural gas hydrates...

This proposal is for an IODP program to constrain models for the formation of deep sea gas hydrate in subduction zone accretionary prisms. The objectives include the deep origin of the methane, its upward transport, its incorporation in gas hydrate, and its subsequent loss to the seafloor. The main attention is on the widespread seafloor-parallel layer of dispersed hydrate located just above th...

In this work the effect of electrolytes on hydrate formation was investigated. To do so, a new model was used in predicting the hydrate formation conditions in presence of both single and mixed electrolyte solutions. The new model is based on the van der Waals - Platteeuw hydrate equation of state. In order to evaluate the values for the activity of water in electrolyte solutions t...

Iran's proved natural gas reserves are the world's second largest reserves. Mainly, because of different climate changes and different reservoirs characterizations, studying the behavior of producing outcome fluids and their transportation, is of major interest. One of the main problems occur in the gas reservoirs is related to the hydrate formation while producing from a well, either in produc...

Gas hydrates are crystalline solids formed from mixtures of water and low molecular weight compounds, referred to as hydrate formers, that typically are gases at ambient conditions (1). Generally, hydrates are formed in the laboratory from two-phase systems by contacting a hydrate former or formers in the gas or liquid phase with liquid water and increasing the pressure until crystalline hydrat...

iran's proved natural gas reserves are the world's second largest reserves. mainly, because of different climate changes and different reservoirs characterizations, studying the behavior of producing outcome fluids and their transportation, is of major interest. one of the main problems occur in the gas reservoirs is related to the hydrate formation while producing from a well, either in produc...

The phase diagram for methane + water is explained, in relation to hydrate applications, such as in flow assurance and in nature. For natural applications, the phase diagram determines the regions for hydrate formation for twoand three-phase conditions. Impacts are presented for sample preparation and recovery. We discuss an international study for “Round Robin” hydrate sample preparation proto...

The stability of hydrate frameworks is influenced by guest molecules capable of hydrogen bonding with surrounding water molecules. Four remarkable features from the ammonium fluoride incorporation into a crystalline hydrate matrix provide important information on the thermodynamic stability, formation kinetics, structural characteristics, and molecular behavior in clathrate hydrate systems.