The discovery that methane from dissociation of gas-hydrates could be an important factor in the global carbon cycle resolves the major discrepancy in estimates of the increase of terrestrial biomass from the Last Glacial period to the present. Carbon isotope budgeting using the marine carbon isotopic record results in an estimate centered around 500 GtC; whereas palaeovegetation reconstruction...

Paleooceanographic evidence has been used to postulate that methane from oceanic hydrates may have had a significant role in regulating global climate, implicating global oceanic deposits of methane gas hydrate as the main culprit in instances of rapid climate change that have occurred in the past. However, the behavior of contemporary oceanic methane hydrate deposits subjected to rapid tempera...

In this communication, a thermodynamic model is presented to predict the dissociation conditions of structure H (sH) clathrate hydrates with methane as help gas. This approach is an extension of the Klauda and Sandler fugacity model (2000) for prediction of phase boundaries of sI and sII clathrate hydrates. The phase behavior of the water and hydrocarbon system is modeled using the Peng-Robinso...

This article provides a detailed analysis of issues related to the complications while drilling in hydrate-bearing rocks permafrost areas. The goal paper is develop recommendations for preventing gas occurrence hydrate deposits and eliminate leakiness intercasing space well. results modeling effect mud injection on temperature field well are presented. It revealed that most significant role pla...

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...

Structural changes and preferential cage occupancies were examined for ethane hydrate and ethane-methane mixed gas hydrates with five compositions in a pressure range of 0.2 to 2.8 GPa at room temperature. X-ray diffractometry and Raman spectroscopy showed the following structural changes. The initial structure, structure I (sI), of ethane hydrate was retained up to 2.1 GPa without any structur...

Gas hydrates form when water and natural gas combine at low temperatures and high pressures — for example, in regions of permafrost and in marine subseafloor sediments. They exist in abundance worldwide and some estimates suggest that the total amount of natural gas bound in hydrate form may exceed all conventional gas resources, or even the amount of all hydrocarbon energy — coal, oil and natu...

In 1811 Sir Humphry Davy, who gained fame for both his research on the methane-laden atmospheres in British coal mines and his synthesis of various new elements and compounds, witnessed the first chlorine hydrate crystallizing. At that time he probably did not imagine that 185 years later methane hydrates would fuel heated debates under the gothic vaults of a former Dominican monastery in Gent....

A new predictive computational method for classifying clathrate hydrate promoter molecules is presented, based on the interaction energies between potential promoters and the water networks of sII and sH clathrates. The motivation for this work is identifying promoters for storing hydrogen compactly in clathrate hydrates. As a first step towards achieving this goal, we have developed a general ...