Blowdown – Definition and Pronunciation
What is Blowdown?
Blowdown is the depressuring of a reservoir through production of gas. This can occur with either gas or oil reservoirs at any stage in their lifecycle.
Examples of Blowdown
Liquid released is collected in a surge drum that is held under a nitrogen or product vapour blanket. Liquid collected is normally returned to the loading line or drained to blowdown, and vapours are usually vented to the vapour recovery system or to a flare.
From “Equipment and cargo system of LNG onshore terminals”.
The difference between opening pressure and reseat pressure is called blow down and is usually expressed as a percentage. For a set pressure of less than 100 mbar the blow down is to be 10-15 % and over 100 mbar the blowdown is to be 3-7 % (in accordance with SIGTTO 2.2 d).
From “LNG Carrier Pressure Relief Systems”.
Liquids that are released during startup or shutdown or other transient periods are routed to the flare knock out drums by liquid blowdown headers separately from the main flare headers.
From “Manual about Liquefied Natural Gas Plant Relief and Flare Systems Design”.
Pronunciation of Blowdown
