Poor Boy Degasser or Mud Gas Seperator, located downstream of the choke manifold, is a vertical vessel used to separate any gas from drilling fluid during well control situation. Once the gas has been separated, it can pass through the vent line in the derrick. Alternatively, as long as it’s a safe distance from the rig, it could even be vented.
Figure 1 – Poor Boy Degasser (Courtesy of H-Screening)
With mud’s separators, there are two main types. Also known as a ‘poor-boy’ and a ‘gas buster’, the more common of the two is called an atmospheric mud/gas separator. However, some mud/gas separators are designed to operate at moderate back pressure. Although these will mostly operate under 100 psig, it’s possible to come across those that work at the atmospheric gas vent line pressure plus the vent line friction drop. The simple diagram of poor boy degasser is show in figure 2.
Figure 2 – Poor Boy Degasser (Mud Gas Separator) Diagram Continue reading
Mud gas separator located at downstream of the choke manifold is one of the important well control equipment that you need to focus. It separates gas out of the mud after the gas comes out of hole. Gas will be vent to atmosphere via the vent line in derrick (offshore operation) or the line away from the rigs (land operation) and the mud will be returned back to the pit.
In the oilfield, people have several names for the mud gas separator as “poor boy degasser” or “gas buster”. While drilling, the mud gas separator should be lined up at all times and filled with the present mud weight currently used.
The concept of this equipment is density difference between liquid and gas. When the mud coming out from the choke manifold goes into the mud gas separator, mud will hit the baffle plates which are used to increase travelling time and allow gas to move out of the mud. Gas which has lower density than air will move up and mud will goes down due to gravity (see – Figure 1). Mud leg will provide hydrostatic pressure in order to prevent mud going through the separator into the rig. Continue reading