5 research outputs found
TECHNICAL LIMITS FOR DEVELOPMENT OF NATURAL GAS HYDRATE DEPOSITS
In this work we have formulated the set criteria for cost-effective selection of technologies for industrial production of gas from a hydrate deposit, which rely on the properties of hydrate-bearing rock and the geologic properties of the gas hydrate deposit. For over forty years the world’s energy industry has been trying to effectively master vast unconventional resources of natural gas – the natural gas hydrates [1;3;4]. Specialists have accumulated during this period of time a great deal of knowledge about gas hydrates [8;10]. They established the conditions of hydrate formation in sedimentary rock and the conditions of formation and disappearance of gas hydrate deposits, and offered several classification methods for gas hydrate deposits. Specialists have proposed several methods to locate the gas hydrate accumulations on land and offshore and determined the probable areas where gas hydrate deposits may exist. More than 220 gas hydrate deposits were found to-date, and methods to calculate the amount of gas in a hydrate deposit were developed [1;12]. The principles of gas production from a hydrate deposit were formulated and real experience of commercial natural gas production from a hydrate deposit was gained. However, until now there were no set economic criteria for selection of effective technologies for industrial development of gas hydrate deposits. This results in periodic development of various models not applicable to specific geologic conditions.Non UBCUnreviewe
Structure H and Structure I Hydrate Equilibrium Data for 2,2-Dimethylbutane with Methane and Xenon
Gas hydrates phase equilibria for structure I and II hydrates with chloride salts at high salt concentrations and up to 200 MPa
Gas hydrates phase equilibria for structure I and II hydrates with chloride salts (NaCl, CaCl2, KCl and MgCl2) were measured at high salt concentrations and up to 200 MPa. The measured equilibrium data represent three-phase (Solution - Hydrate - Vapor) or four-phase (Solution - Hydrate - Salt precipitated - Vapor) equilibrium depending on the salt concentration. The hydrate phase boundary with salts was shifted to lower temperatures and higher pressures when the experimental system was below the salt saturation concentration, while the boundaries were unchanged at salt concentrations above saturation, corresponding to quadruple points. The experimental data were compared with hydrate equilibrium predictions calculated by commonly used predictive tools to assess the reliability of these tools for the brines and conditions considered. The comparison demonstrates that predictive tools exhibit large deviation to the measured data, especially at high pressures and high salinity conditions. (C) 2017 Elsevier Ltd.113sciescopu
Gas Hydrates Phase Equilibria and Formation from High Concentration NaCl Brines up to 200 MPa
Gas
hydrate phase equilibrium and kinetics at high NaCl concentrations
(near and at saturation in solution) and very high pressures (up to
∼200 MPa) are investigated to study the interplay of hydrate
formation and salt precipitation. Limited experimental data above
80 MPa exist for hydrate phase equilibrium in high salinity systems.
This study reveals the unusual formation of gas hydrates under these
extreme conditions of high salinity and very high pressure. In particular,
the results demonstrate that hydrates can form from saturated salt
solutions, and the formation of hydrates and salt precipitation are
competing effects. It is determined that hydrates will remain in equilibrium
with a saturated salt solution, with the amount of salt precipitation
determined by the amount of hydrates formed. These data are essential
fundamental data for gas hydrates applications in the oil and gas
production flow assurance and seawater desalination