swab valve การใช้

• Some trees have a second swab valve, the two arranged one on top of the other.
• The Xmas trees have the unusual property of having two Swab valves, rather than just one.
• The valve at the top is called the swab valve and lies in the path used for well interventions like wireline and coiled tubing.
• However, avoiding delaying production for a day is usually too small a gain to be worth the extra expense of having a Christmas tree with a second swab valve.
• For such operations, a lubricator is rigged up onto the top of the tree and the wire or coil is lowered through the lubricator, past the swab valve and into the well.
• With only a single swab valve, the upper master valve is usually closed to act as the second barrier, forcing the well to be shut in for a day during rig down operations.