From Surf Wiki (app.surf) — the open knowledge base
Mud Gas Separator

Mud Gas Separator is commonly called a gas-buster or poor boy degasser. It captures and separates the large volumes of free gas within the drilling fluid. If there is a "kick" situation, this vessel separates the mud and the gas by allowing it to flow over baffle plates. The gas then is forced to flow through a line, venting to a flare. A "kick" situation happens when the annular hydrostatic pressure in a drilling well temporarily (and usually relatively suddenly) falls below that of the formation, or pore, pressure in a permeable section downhole, and before control of the situation is lost.
It is always safe to design the mud/gas separator that will handle the maximum possible gas flow that can occur.
Types of Mud/Gas Separators
The principle of mud/gas separation for different types of vessels is the same.
- Closed bottom type
- Open bottom type
- Float type The closed-bottom separator, as the name implies, is closed at the vessel bottom with the mud return line directed back to the mud tanks. Commonly called the poor boy, the open-bottom mud gas separator is typically mounted on a mud tank or trip tank with the bottom of the separator body submerged in the mud. Fluid level (mud leg) is maintained in a float-type mud gas separator by a float/valve configuration. The float opens and closes a valve on the mud return line to maintain the mud-leg level. According to pedestal or base type there are:
- Fixed type
- Elevating type
Poor boy degassers are usually named according to the vessel diameter. Types include:
- MGS800
- MGS1000
- MGS1200
- MGS1400
The degasser type or configuration is typically customisable.
Principle of operation
The principle behind the mud gas separator is relatively simple. On the figure, the mud and gas mixture is fed at the inlet allowing it to impinge on a series of baffles designed to separate gas and mud. The free gas then is moved into the flare line to reduce the threat of toxic and hazardous gases and the mud then discharges to the shale shaker and to the tank.
Notes
References
- Dilling Fluids Processing Handbook {{ISBN. 0-7506-7775-9
- Mud Equipment Manual {{ISBN. 0-87201-614-5
- SPE Drilling Engineering, December 1991
- "Solids control Mud Gas Separators".
This article was imported from Wikipedia and is available under the Creative Commons Attribution-ShareAlike 4.0 License. Content has been adapted to SurfDoc format. Original contributors can be found on the article history page.
Ask Mako anything about Mud Gas Separator — get instant answers, deeper analysis, and related topics.
Research with MakoFree with your Surf account
Create a free account to save articles, ask Mako questions, and organize your research.
Sign up freeThis content may have been generated or modified by AI. CloudSurf Software LLC is not responsible for the accuracy, completeness, or reliability of AI-generated content. Always verify important information from primary sources.
Report