Degassing devices for solids control2013-05-31
In solids control system, there are two kinds of degassing devices: Mud gas separators and Vacuum degassers.
Mud gas separators are the first units of solids control equipment arranged to treat mud. As such, they process all of the mud from the flowline before the mud reaches the primary shale shakers. The units have no moving parts and rely on the density difference between the gas and the mud for removal. The process is simple, yet very effective.
Vacuum degassers utilize negative pressure to withdraw entrained gases from the mud. In order for this to work, mud is pumped through a venturi, which develops a negative pressure, thus sucking mud into the unit. The mud then flows over dispersion plates, arranged either horizontally or vertically, creating thin sheets of gas-cut mud. These dispersion plates bring entrained gases closer to the surface for easy removal by a stand-alone vacuum pump. The choice between horizontally- or vertically-mounted units is typically based on the footprint requirements of the specific rig.
The handling capacity of vacuum degasser is less than the mud gas separator, but can eliminate gas more thoroughly. Generally the drilling fluid disposed by mud gas separator still contains minute bubbles, after through shale shaker, and enter into the vacuum degasser to dispose.