Side effects of low dosage hydrate inhibitor application in the multi phase sea line

The South Pars Gas Field phases 2 & 3 in Iran is wet scheme base design: no process is performed offshore, all the produced fluids (gas, condensate, glycolated-water) are directly sent to shore through two 32 multi-phase pipelines. In the presence of free water during the ransporting, there is a risk of hydrate formation. In order to avoid hydrate formation, MEG as a thermodynamic hydrate inhibitor is injected to well production .Furthermore, due to amines additives presence in MEG solution, it can also act as a corrosion inhibitor. Liquids separated in the slug catchers are sent respectively to the condensate stabilization unit. The function of this unit is to remove the lightest components of the raw feed and to produce stabilized condensate. MEG is sent to glycol regeneration unit and is stored in lean MEG tanks for transferring to offshore via two 4 piggy back lines. Corrosion inhibitor and LDHI (KHI) mode was considered as a backup solution in case of piggy-back line rapture, or main MEG injection pumps failure. This plant has good experiences on usage of KHI/CI and excellent protection from corrosion and hydrate side was gained .But during this mode some problem were observed in downstream units ,even caused to produce off spec product. In this work some major problems related to KHI and CI injection and investigation results will be described.

کلیدواژه ها:

Low Dosage Hydrate Inhibitor ، Sea line ، MEG