Differences Between Drilling Vacuum Degasser and Liquid-Gas Separator

Drilling fluid degassing equipment is critical to ensuring drilling safety and efficiency. The vacuum degasser and liquid-gas separator are two common devices, differing in function, working principle and characteristics. TR Solids Control, a professional solids control equipment manufacturer, analyzes the differences to guide equipment selection for drilling operations.

Liquid-Gas Separator: Primary Defender Against Gas-Invaded Drilling Fluid

As a primary degassing device for gas-invaded drilling fluid, it plays an irreplaceable role in drilling fluid treatment system. Liquid-Gas Separator mainly designed to remove large bubbles (≥Φ3mm) from gas-cut drilling fluid, as well as hazardous hydrogen sulfide and other toxic gases, serving as vital safety device to prevent blowouts in oilfield drilling.

Its internal structure features unique baffles that extend gas residence time in the tank for optimized separation. When gas-invaded mud enters the tank tangentially through the inlet pipeline, the tank’s pressure design and baffle structure force the fluid to swirl. Centrifugal force and gravity enable preliminary gas-liquid separation: gas rises to the top, passes through demister to filter out liquid particles, and is then led to safe area via dedicated exhaust pipeline for combustion and emission. The degassed heavy mud settles at the tank bottom and re-enters the solids control system for reuse. This fast, continuous process stabilizes drilling fluid performance and gains valuable time for wellhead pressure control, making it the first line of defense for drilling safety.

Vacuum Degasser: Deep Purifier for Drilling Mud

A key device in the drilling solids control system for removing harmful gases from drilling mud, the vacuum degasser targets smaller micro-bubbles in the mud. It can also function as a large-scale mud agitator to facilitate drilling fluid performance adjustment.

Its working principle is completely different from that of the liquid-gas separator. A vacuum pump creates vacuum inside the degasser main body, and atmospheric pressure presses the mud into the device. The impeller inside the degasser spins and flings the gas-invaded mud toward the inner wall, causing bubbles in mud to burst and achieve degassing. This method enables deep removal of micro-bubbles, purifies drilling fluid thoroughly, improves its performance and boosts drilling efficiency. With negative-pressure environment to force bubble rupture, its degassing efficiency reaches over 95%.

Key Differences Summary

Function: The liquid-gas separator focuses on primary degassing of gas-invaded drilling fluid, mainly handling large bubbles and toxic gases as a critical safeguard against blowouts. The vacuum degasser specializes in deep removal of micro-bubbles and harmful gases, and also has an agitator function.

Working Principle: The liquid-gas separator relies on centrifugal force and gravity for preliminary gas-liquid separation; the vacuum degasser uses a vacuum environment to burst bubbles in the mud.

The two devices work in coordinated and progressive manner to ensure smooth and safe drilling operations. Rational equipment selection based on actual drilling needs can significantly improve drilling fluid treatment efficiency and enhance overall drilling quality.

TR Solids Control provides customized liquid-gas separators, vacuum degassers and other drilling fluid degassing equipment for diverse drilling conditions. Manufactured with high-quality corrosion-resistant materials, all equipment complies with API standards and HSE management system requirements, delivering reliable support for safe and efficient oilfield drilling.