Results of the experimental study of effects of the composition and pressure of gas on thermal conductivity and heat capacity of frozen and thawed sand saturated with different gases (nitrogen, methane, carbon dioxide, and a mixture of gases (50 % CH4 + 50 % CO2)) have been presented. In the experiments, the maximum gas pressure was set below the pressure of formation of gas hydrate. The experiments were carried out in a specially designed system with a pressure chamber, which enabled measurements of thermophysical characteristics of the pressurized sediments at temperatures below and above freezing. The first ever data on the effect of gas pressure on thermal conductivity and heat capacity in the freezing sand saturated with different gases were obtained. The experiment results revealed that thermophysical characteristics of the unfrozen gas-saturated sand samples are practically independent of the composition and pressure of gas. It has been established that a pressure increase in some saturating gases (N2, CH4, a mixture of gases CH4 + CO2, and CO2 ) was responded by a reduction in thermal conductivity of the frozen sand sample, against an increase in heat capacity. Carbon dioxide as highly soluble gas affecting the composition of unfrozen pore water, has the greatest influence on changes in the thermophysical parameters.
|Translated title of the contribution||Influence of the composition and pressure of gas on thermophysical properties of gas-saturated frozen and thawed sands|
|Number of pages||7|
|Publication status||Published - 2020|