Types of Mud Gas Separators2013-03-13
Three types of mud gas separators commonly are used today: closed bottom, open bottom, and float type. The principle of mud gas separation within each type of vessel is identical. Differences can be found in the method of maintaining the mud leg.
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. Mud leg is maintained in the separator by installation of an inverted U-shaped bend in the mud return line. Fluid level can be adjusted by increasing/decreasing the length of the U-shaped bend.
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. The fluid level (mud leg) in the separator is controlled by adjusting the fluid level in the mud tank or by moving the separator up or down within the tank. Mud-tank height can restrict the maximum mud leg obtainable for open-bottom mud gas separators.
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. Valves can be operated by a manual linkage system connected from the float to the valve, or the valve can be air-operated with rig air. Mud-leg height can be controlled by adjusting the float assembly.