Experimental study of Iranian natural gas hydrate formation using Persian Gulf seawater in the presence or absence of propanol as a thermodynamic inhibitor

Abstract

ABSTRACT Gas hydrates are crystalline compounds that are obtained from gas molecules trapped in cavities due to hydrogen bonding of water. Iran is among the countries that have rich reserves of natural gas and one of the issues related to the natural gas is gas hydrate formation that can cause problems in the oil and gas industry. However, in recent research hydrates’ formation is mentioned as an advantage for specific uses. But this phenomenon occurred in natural gas transmission pipelines causes an increasing pressure drop, obstruction of gas transmission pipelines. The purpose of this study is to examine the natural gas hydrate formation in the presence or absence propanol as the thermodynamic inhibitor in a closed system experimentally. In this research, for the formation of gas hydrates, natural gas of the Gachsaran region of Iran and the Persian Gulf Seawater (instead of pure water) has been used. In this study, solutions containing inhibitors were examined in three weight percentages of 5, 15 and 25 and their results were also compared with each other. The results of the experiments showed that under identical conditions, Gachsaran natural gas hydrates are formed in the presence of Persian Gulf seawater at a lower temperature than pure water. It was also found that by increasing the concentration of inhibitor, the equilibrium temperature of hydrate formation is reduced and more equilibrium pressure is needed for hydrate formation.