INJECTION OF MONOETHYLENE GLYCOL TO PREVENT HYDRATE FORMATION IN DEEPWATER GAS-FIELD FLOWLINE

• Main Author: Parubak, Enos
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/32702
• Institution: Institut Teknologi Bandung

The presence of hydrates in oil and deep-sea gas operations is a fairly frequent issue, in order to ensure that flow assurance does not suffer during the operation. This study analyzed the sensitivity of the hydrate compound formation process in a pipeline system with a diameter of 9.5 "with a length of about 72,000 ft (22 km) in deep sea gas field, in actual condition and production rate assumption. Based on the simulation results for the actual production flow rate, the hydrate is formed at a distance of about 17991 ft (5.48 km) from the wellhead that is in the first segment of the well head to the Pipeline End Manifold (PLEM). Hydrate formation occurs at a distance approaching the wellhead for an increased flow rate and also in the first segment. In this analysis, there was also a study of the addition of Monoethylene Glycol (MEG) inhibitors to prevent the formation of hydrate compounds. Fluid flow modeling was performed under steady conditions with CH4 levels of about 87%, pressure of 1900 psig, temperature 125oF, and H2O 22 BPD (0.27% mol) content and 85 MMSCFD flow rate as base condition. In this basic condition, the MEG addition of 55 barrels per day (0.22% mole) is applied according to the actual condition to prevent hydrate. To determine the optimal amount of MEG addition, optimization of MEG amount at 0.175%, 0.195% and 0.215% mole for each production flow rate was performed. In addition MEG 0.175% lowered the hydrate forming temperature from 68.8oF to 3.32oF. Similarly, for increasing MEG doses, the greater the decrease in hydrate formation temperature. The addition of MEG 0.175% mole at each production flow rate gives the difference of hydrate formation temperature without MEG (subcooled degree) of 65.48oF, and greater with increasing MEG dosage, so as to be safe from the risk of hydrate.