Perpustakaan Digital ITB

The formation of gas hydrates has been one of major production problems in oil and gas industry, especially in cold environment where gas hydrates can possibly form. Technically, gas hydrates are crystalline solids that are formed by gas molecules that are trapped inside water molecule cages. When the producing fluids contain enough gas and free water, with the right condition these crystalline solids can form inside production line. Moreover, the formation of gas hydrates inside pipeline should be treated immediately because they can cause production problems related to flow assurance such as plugging. Gas hydrates plugging can block pipelines and they can also lead to a pipe blast when the pressure rises. In this paper, the author will discuss about sensitivity study to prevent the occurrence of gas hydrate inside pipeline in “X” gas field. There are two basic gas hydrates prevention methods that will be discussed in this paper. First method is by injecting chemical that acts as gas hydrates inhibitor into pipeline through three injection spots. Inhibitors that were used to prevent the formation gas hydrates in this paper include Methanol, Ethylene Glycol, Diethylene glycol and Triethylene glycol. The second method is by using heat to prevent gas hydrate formation and keep the fluid above the temperature of gas hydrates formation. As the base case, the flow lines are located above ground with various elevations and 60.62°F ambient temperature. Heating methods that will be discussed in this paper include burying pipe into the ground with different depths and adding pipe thermal insulator with different thickness. This study was done by doing several simulations using PIPEPHASE software where the author conduct a sensitivity study by changing some parameters so the fluid will not flow into the zone with pressure and temperature where gas hydrates can be form.