Thermodynamic Inhibitors for Hydrate Plug Melting

Abstract

Abstract: The hydrate melting efficiency of thermodynamic inhibitors has been shown to depend on hydrate plug properties, inhibitor properties, and the turbulence of the liquid system in question. Inefficient mixing of inhibitor and water, lack of contact between inhibitor and hydrate, and a solid or gel precipitation in the melting region have been demonstrated to give low melting efficiency. MeOH seems to be the most efficient inhibitor for melting porous plugs, but may not melt a plug with low porosity. MEG has the ability to penetrate into a compact plug and cause melting. However, when used at high concentrations, MEG may freeze out as a solid or gel, which can lead to reduced hydrate melting efficiency. At high pressures and in the presence of a hydrocarbon liquid, MEG solutions were shown to freeze out at temperatures more than 30°C higher than values given in the literature. TEG seems to easily freeze and become inefficient for melting hydrate plugs.