How to evaluate a Mud gas separator

The mud gas separator is used in a ‘kick’ situation to separate large volumes of free gas invaded in the drilling fluid.

 Function of Mud gas separator

 Mud gas separator also called poor boy degasser, Gus buster, which is designed to provide effective separation of the drilling mud and invaded gas from the well by venting the gas and returning the mud to the mud pits. Small amounts of entrained gas can then be handles by a

liquid gas separator
liquid gas separator

vacuum-type degasser located in the mud pits. The mud/gas separator controls gas cutting during kick situations, during drilling with significant drilled gas in the mud returns, or when trip gas is circulated up.

 Mud leg height is an important parameter for the mud gas separator, you need to clear it during evaluation.

 What is Mud leg?

The mud leg in the separator is controlled by adjusting the fluid level in the mud tank or by moving the separat6or up or down within the tank. Mud tank height can restrict the maximum mud leg obtainable for open-bottom mud gas separator.

 Mud leg is an important part for mud gas separator, it is also called Fluid level. Fluids level is maintained in a float mud gas separator by a float/valve configuration. The float opens and closed a valve on the mud return line to maintain the mud leg level. Valves can be operated by manual linkage system connected from the float to the valve, or the valve can be air-operated with the rig air. Mud leg height can be controlled by adjusting the float assembly.

 There are some inherent problems in the use of float-type mud gas separators. The manual linkage separator has experienced problems with linkage failure resulting in improper opening or closing of the mud return line valve. Air-operated valves fail to function if rig air is lost, resulting in no control of fluid level within the separator. Mud-return-line valves are prone to plug with solids, preventing mud flow back to the mud pits.

 Gas Flow calculation is another important issue to evaluate the mud gas separator.  

Usually we need to calculate the following items.

1 The maximum exhaust per second

2 The maximum exhaust per hour

For the calculation, we need to provide the dimension of vent lines, which is shown in the sketch.

Welcome to discuss the technical specification with GN technician, so we can improve our design to suit for international market use.

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