ali Esmailzadeh - Chemical Science and Technology Research Division, Research Institute of Petroleum Industry (RIPI)P.O. Box: 14665-137, Tehran, I.R. IRAN
Khodadad Nazari - Chemical Science and Technology Research Division, Research Institute of Petroleum Industry (RIPI)P.O. Box: 14665-137, Tehran, I.R. IRAN
Ghasem khatinzadeh - Chemical Science and Technology Research Division, Research Institute of Petroleum Industry (RIPI)P.O. Box: 14665-137, Tehran, I.R. IRAN

Low dosage kinetic hydrate inhibitors (KHIs) commonly used to prevent hydrate blockages in offshore pipelines. These chemicals are designed such that they prevent hydrates from growing once nucleation has started. This is much different than thermodynamic inhibition (i.e. alcohol) in that the formation conditions of the hydrates are not altered. The KHI.s prevent hydrate crystals from growth by adsorption on the crystal surface and inserting the pendant group into the hydrate cages.Evaluations of KHIs in laboratory high pressure stirred vessel were carried at various initial pressure and temperature values.As constituents of pipeline natural gas (ethane mole ratio), the amount of kinetic hydrate inhibitor was calculated by HWHyd software. The commercial KHIs based on polyvinyl pyrrolidone forms more hydrate amount (ΔP), in relation to its second hydrate temperature. Furthermore, the performances of the commercial formulations are much better than the polyvinyl caprolactam

natural gas, hydrate, pipeline, polymeric kinetic hydrate inhibitor, polyvinylpyrrolidone