Vacuum Degasser: How to Use a Vacuum Degasser in Drilling Mud System

In modern oil and gas drilling operations, the vacuum degasser plays a critical role in maintaining drilling fluid stability. When gas invades the drilling mud, it reduces mud density, affects rheological properties, and may even lead to well control risks.

A vacuum degasser is designed to efficiently remove free gas from drilling fluid and restore its original performance.

In this article, we will explain how to use a vacuum degasser properly, including startup procedures, operating steps, precautions, and maintenance tips.

What Is a Vacuum Degasser?

A vacuum degasser is a solids control device installed after the shale shaker. Its main function is to remove entrained gas from gas-cut drilling fluid using negative pressure.

When gas enters the mud system, it can cause:

• Reduction in mud density

• Pump cavitation

• Poor separation performance of desander/desilter

• Decreased centrifuge efficiency

• Potential well control hazards

Installing a vacuum degasser helps ensure system stability and drilling safety.

Position of Vacuum Degasser in Solids Control System

In a standard drilling solids control system, the vacuum degasser is installed in the following sequence:

Shale Shaker → Vacuum Degasser → Desander → Desilter → Decanter Centrifuge

This layout ensures gas removal before fine solids separation, protecting downstream equipment.

How to Use a Vacuum Degasser

1. Pre-Start Inspection

Before starting the vacuum degasser, check the following:

• Power supply and motor wiring

• Vacuum pump condition

• Belt tension (if belt-driven)

• Mechanical seals

• Inlet and outlet valves

• Ensure suction pipe is submerged in mud

Proper inspection prevents mechanical damage and ensures stable vacuum performance.

2. Start-Up Procedure

Step 1: Turn on the main motor.
The vacuum pump begins creating negative pressure inside the tank.

Step 2: Check the vacuum gauge.
Normal working vacuum range:

• -0.03 MPa to -0.05 MPa

If vacuum cannot reach this range:

• Check for air leakage

• Inspect seals

• Verify vacuum pump condition

Step 3: Open the mud inlet valve.
Mud enters the vacuum tank where:

• Gas rapidly expands under negative pressure

• Gas bubbles break

• Gas is discharged through the exhaust port

Degassed mud flows out from the bottom discharge outlet.

3. During Operation

Monitor the following:

• Continuous gas discharge from exhaust port

• Stable vacuum level

• Smooth mud flow

• No abnormal vibration or noise

If no gas is discharged, the mud may have low gas content, which is normal.

Important Operating Precautions

Avoid Dry Running

Never operate the vacuum degasser without mud supply.
Dry running can damage:

• Mechanical seals

• Impellers

• Vacuum pump

Immediately stop the machine if mud supply stops.

Use in Gas-Invasion Situations

When drilling through gas-bearing formations, start the vacuum degasser early.

Waiting until mud density drops significantly may:

• Affect well control

• Reduce separation efficiency

• Impact centrifuge performance

Ensure Smooth Discharge

Degassed mud must flow freely to the next solids control stage to prevent overflow or pressure build-up.

How a Vacuum Degasser Improves System Efficiency

A properly operated vacuum degasser helps:

• Restore mud density

• Improve pump performance

• Increase desander and desilter efficiency

• Protect decanter centrifuge

• Reduce overall operational risk

It is especially critical in deep wells, gas wells, and underbalanced drilling projects.

Vacuum Degasser Maintenance Tips

To extend service life:

• Regularly inspect mechanical seals

• Check vacuum pump oil level

• Clean exhaust pipeline

• Avoid long-term idle operation without cleaning

• Perform routine system inspection

Proper maintenance reduces downtime and improves reliability.

Conclusion

The vacuum degasser is an essential component of any drilling mud solids control system. Correct operation ensures efficient gas removal, stable mud performance, and safer drilling operations.

If you are looking for a reliable vacuum degasser for oil and gas drilling, choose a manufacturer with strong engineering support and proven field experience.