Impact of Thermodynamic Model on the Simulation of natural Gas Dehydration Unit

At the wellhead, reservoir fluids almost invariably contain water and consequently natural gas is produced saturated with water. There are some vital reasons for dehydration of natural gas which made it necessary for each gas processing unit. A typical natural gas dehydration plant, which employs triethyleneglycol (TEG) as the dehydrating agent, is simulated using a steady state simulator (HYSYS) to explore the effects of the thermodynamic model employed in the simulator on the reliability of the whole simulation process. The three most commonly used EOS in the simulation of TEG dehydration units are Peng–Robinson (PR), PRSV (Soave and Vera modification of PR equation of state) and Lee-Kesler-Plocker. Solvent circulation rate, water content in the dehumidified natural gas, purity of the regenerated TEG, and reboiler heat duty are the parameters for comparing different case studies. In this study results of the simulation of dehydration plant are compared with the field data. Very diverse results have been obtained from the different models. None of these models give an acceptable result for all criteria.

Keywords:

Natural gas dehydration , thermodynamic model , TEG