Mud Gas Separator is commonly called a gas-buster or poor boy degasser

Degasser

A degasser is a device used in drilling to remove gasses from drilling fluid which could otherwise form bubbles.-Degasser:For small amount of entrained gas in a drilling fluid, the degasser can play a major role of removing small bubbles that a liquid film has enveloped and entrapped...

. It captures and separates large volume of free gas within the drilling fluid

Drilling fluid

In geotechnical engineering, drilling fluid is a fluid used to aid the drilling of boreholes into the earth. Often used while drilling oil and natural gas wells and on exploration drilling rigs, drilling fluids are also used for much simpler boreholes, such as water wells. Liquid 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 and vent it to a flare

Gas flare

A gas flare, alternatively known as a flare stack, is an elevated vertical conveyance found accompanying the presence of oil wells, gas wells, rigs, refineries, chemical plants, natural gas plants, and landfills....

. A "KICK" situation happens when the annular

Annulus (oil well)

The annulus of an oil well refers to any void between any piping, tubing or casing and the piping, tubing, or casing immediately surrounding it. It is named after the corresponding geometric concept...

 hydrostatic pressure

Fluid statics

Fluid statics is the science of fluids at rest, and is a sub-field within fluid mechanics. The term usually refers to the mathematical treatment of the subject. It embraces the study of the conditions under which fluids are at rest in stable equilibrium...

 in a drilling well temporarily (and usually relatively suddenly) falls below that of the formation, or pore

Pore water pressure

Pore water pressure refers to the pressure of groundwater held within a soil or rock, in gaps between particles . Pore water pressures in below the phreatic level are measured in piezometers...

, pressure in a permeable section downhole

Downhole oil water separation technology

Downhole oil–water separation technology is an emerging technology that separates oil and gas from produced water at the bottom of the well, and re-injects most of the produced water into another formation which is usually deeper than the producing formation, while the oil and gas rich stream are...

, 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

According to pedestal or base type there are

• Fixed type
• Elevating type

Poor boy degasser in China is usually named according to vessel diameter.So the type also including

• FLQ800 or ZYQ800
• FLQ1000
• FLQ1200
• FLQ1400

Usually, the degasser type or configuration is customizable

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.