Mud gas separator in mud treating

Oil/gas drilling rig poor boy degasser

Poor boy degasser is an efficient item to get rid of large quantities of toxic gas among drilling fluid. This blog will introduce more info on poor boy degasser about the basic structure, the simple principle and how to design a poor boy degasser.


Poor boy degasser structure

  • We all know, poor boy degasser is also called mud gas separator or gas buster. One glossary ever described it as a simple separator vessel used to remove free or entrained gas from fluids circulated in the wellbore, such as mud used during drilling operations. The gas buster typically comprises a vessel containing a series of baffles with a liquid exit on the bottom and a gas-vent line at the top of the vessel.


  • Above is a simple description on poor boy degasser. The oil and gas drilling rig poor boy degasser completely includes base support, main vessel, fluid inlet, baffles, drain valve, vent line, discharge output, pressure gauge, relief valve, and lay down legs.

If requested by clients, the vent line should be supplied together with degasser. Usually, there will be 30m or 50m for option.

Oil rig poor boy degasser principle

1. Oil rig poor boy degasser basic working principle is the drilling fluid flow into feed inlet. After going through baffles the air bubble will break down and flow up. The drilling mud will flow down till the discharge output. It is different with vacuum degasser.

2. We know, on poor boy degasser, there is necessary mud seal/mud leg. ?U tube on discharge output will result the mud seal. Its function and effect is to prevent discharged gas flow together with drilling fluid after degassing.

3. Usually, for oil and gas drilling rig, after the poor boy degasser the drilling fluid will flow to shale shaker for subsequent solids control process.


Above is the simple principle of poor boy degasser working. Following will be the design on poor boy degasser.

How to design poor boy degasser

Former content introduced basic principle and structure. So now the design is more simple and clearer.

First of all, the poor boy degasser is almost designed as vertical type. It is closed bottom vessel type. Poor boy degasser for oil and gas drilling rig includes 600mm, 800mm, 1000mm, and 1200mm diameter. ?The feed inlet usually is 5″, output discharge is 10″ or 8″, while the vent line will be 8″ diameter. But customizable dimension is available upon users’ demand.

The poor boy degasser feed inlet connected with choke manifold. The output line will be connected with shale shaker inlet line or flow divider. Vent line is connected to flare line.

Regarding to the liquid leg, we usually design it as 12 ft line. As we said before, the mud seal will prevent drilling mud with remain toxic. Sufficient mud seal will lead good performance.?Furthermore, there will be 4-5 baffles mounted on vessel wall.

Finally, is to design the support base. It can be fixed type or elevating/folding type. More and more clients prefer the folding base poor boy degasser for its flexibility and convenience at oil drilling job site.

If you need poor boy degasser, please contact OGEM Equipment. We have poor boy degasser for sale now.