Refrigeration

Natural Gas Processing & NGL Compressor Lubricants

Natural gas processing compressor lubricants are selected according to gas composition, compressor design and the actual pressure and temperature conditions at each point in the processing plant. NGL-rich gas can contain significant concentrations of ethane, propane, butane and heavier hydrocarbons. Where these gases come into direct contact with the lubricant, they can dissolve into the oil and reduce its operating viscosity. Heavier hydrocarbon gases and increasing pressure can increase this dilution effect, making in-service viscosity an important consideration in rich-gas compression. NEXT Lubricants supplies compressor lubricants for feed and residue gas compression, NGL recovery, hydrocarbon dew-point control, fractionation support and refrigeration compressors used throughout natural gas processing facilities.

Compression process

Natural Gas Processing & NGL: Process, Applications & Compressor Role

Natural gas processing plants remove water and other unwanted components and recover natural gas liquids such as ethane, propane and butane from the incoming gas stream. The remaining dry or residue gas is then prepared for pipeline transport.

Compressors operate at several points throughout the plant and can handle very different gas compositions. Rich feed gas can create significant lubricant-dilution challenges where the gas contacts the oil, while lean residue-gas duty is generally less severe from a hydrocarbon-solubility perspective. Compressor design and the location of the lubricant system must therefore also be considered.

Feed & Residue Gas Compression

Feed-gas compressors raise incoming gas to the pressure required for processing, while residue-gas compressors handle the leaner gas remaining after NGL recovery for downstream transport or export.

NGL Recovery & Fractionation

Compression supports natural-gas-liquid recovery and process stages associated with deethanizing and fractionation, where recovered hydrocarbons are separated into products such as ethane, propane and butanes.

Hydrocarbon Dew-Point Control

Gas-processing facilities control hydrocarbon dew point to prevent heavier hydrocarbons from condensing after the treated gas leaves the plant. Compressors associated with these processes can handle streams close to condensation conditions.

Gas-Plant Refrigeration

Mechanical refrigeration, commonly including propane refrigeration, is used in many processing facilities to cool natural gas and support NGL recovery. Lubricant selection for the refrigeration compressor itself follows the refrigerant and compressor operating conditions.

Cryogenic NGL Recovery

Cryogenic processing can recover large fractions of ethane and almost all propane and heavier hydrocarbons from the natural-gas stream. Where lubricated compression forms part of the process, low-temperature conditions and compressor design become additional lubricant-selection factors.

Lubrication Considerations

CO₂ refrigeration places different demands on compressor lubricants from conventional HFC, HFO and ammonia refrigeration. The most important considerations are refrigerant solubility, operating viscosity, pressure, low-temperature behavior, oil return and moisture control.

Gas Dilution and Operating Viscosity

Where process gas contacts the lubricant, heavier hydrocarbons can dissolve into the oil and reduce its viscosity. The degree of dilution depends on gas composition, pressure, temperature and lubricant chemistry. Selection should therefore target adequate in-service viscosity, not fresh-oil ISO grade alone.

Liquid Hydrocarbon Carry-Over

Condensate or other hydrocarbon liquids entering the compressor can reduce lubricant viscosity and disrupt the lubricating film. Lubricant selection cannot correct a mechanical liquid-carryover problem, so suction separation and actual operating conditions must also be evaluated.

Gas Composition Across the Plant

Feed, intermediate and residue streams can differ considerably in methane, ethane, C3+ hydrocarbons, water and other components. A lubricant suitable for lean residue gas is therefore not automatically suitable for an NGL-rich process compressor.

Compressor Design

Lubricant exposure to the process gas depends on compressor design. Lubricated reciprocating cylinders and oil-injected compressors experience direct gas-oil interaction, while some centrifugal compressors use dry gas seals and separate oil-lubricated bearings.

products

Recommended NEXT Natural Gas Processing & NGL Compressor Lubricants

NEXT GPL PAG

Light–Medium Hydrocarbon Compression

Base Oil: PAG

ISO Range: 32 – 680

View Product →

NEXT GPL PAG-WS

Medium–Heavy / High-Dilution Hydrocarbon Compression

Base Oil: PAG-WS

ISO Range: 32 – 460

View Product →

NEXT GPL PAG-EO

Heavy Hydrocarbon / Very Low-Dilution Compression

Base Oil: PEG

ISO Range: 32 – 220

View Product →

NEXT GPL PAO

Light to Medium Hydrocarbon Compression Lubricant

Base Oil: PAO

ISO Range: 32 – 320

View Product →

NEXT GPL MIN

Light Hydrocarbon / Wet-Gas Compression

Base Oil: Mineral

ISO Range: 32 – 680

View Product →

Cross reference tool

1 Select competitor brand

2 Enter oil code or name

Enter a competitor oil above to get started

Results will appear here instantly

Specifications

Product code

Oil type

ISO viscosity grade

Applications

Specifications

Oil type

ISO viscosity grade

Equivalence

View product page →

No equivalent found

We don't have a listed match for "".
Our technical team can help identify the right product.

Contact Our Experts

Recommendation

Technical Support, Compatibility and Cross-Reference Documentation

Changing compressor lubricant brands requires confidence that the replacement lubricant is suitable for both the compressor and the existing oil in the system.

NEXT Lubricants provides technical support for lubricant conversions and replacement projects.

Over more than 10 years, we have built an internal database comparing the compatibility and performance of NEXT lubricants with many commonly used industrial compressor oils.

Frequently Asked question

What type of oil is used in natural gas processing compressors?

Natural gas processing compressors can use mineral, PAO, PAG, water-soluble PAG or PEG lubricants depending on gas composition, compressor design and operating conditions. Rich hydrocarbon streams may require greater dilution resistance, while lean processed gas can often use PAO or mineral chemistry where permitted by the OEM.

Why does NGL-rich gas reduce compressor oil viscosity?

Heavier hydrocarbons can dissolve into compressor oil where the process gas contacts the lubricant. This reduces the viscosity of the gas-oil mixture and can decrease lubricating-film thickness. The degree of dilution depends on gas composition, pressure, temperature and lubricant chemistry.

Does NGL-rich gas always require a higher ISO viscosity grade?

No. A higher starting viscosity is one possible way to compensate for gas dilution, but a more dilution-resistant lubricant chemistry may be the better solution. The correct approach depends on the gas composition, compressor, pressure, temperature and required in-service viscosity. Ariel likewise recommends considering either heavier ISO grades or synthetic lubricants resistant to dilution depending on the application.

Can I use one lubricant across the entire natural gas processing plant?

Not necessarily. Feed gas, NGL-rich process streams and lean residue gas can have very different compositions and lubricant-dilution behavior. Different compressor designs can also expose the lubricant to the gas differently, so selection should be made compressor-by-compressor rather than applying one oil automatically across the plant.

What is the difference between PAG, PAG-WS and PEG for NGL-rich gas?

Standard PAG provides good dilution resistance for lighter hydrocarbon service. PAG-WS uses EO/PO chemistry for greater resistance with heavier hydrocarbons, while NEXT GPL PAG-EO is a PEG lubricant designed for very low hydrocarbon solubility where severe dilution is the primary concern.

Does propane refrigeration in a natural gas plant use the same lubricant as the process-gas compressors?

Not necessarily. Propane refrigeration is a separate compressor duty with its own refrigerant, evaporating temperature, compressor design and lubricant requirements. Its role in NGL recovery belongs on this page, while detailed lubricant selection for the refrigeration compressor is covered under Hydrocarbon Refrigeration.

What information is most important when selecting a natural gas processing compressor lubricant?

The most important inputs are the compressor manufacturer and type, complete gas composition, suction and discharge pressures, suction and discharge temperatures and any liquid carry-over history. For rich gas, C3+ composition is particularly useful when evaluating potential lubricant dilution.

Related Applications

Explore Other Gas Compression Applications

Natural Gas Gathering

Lubricants for compressors handling raw, wet and variable-composition gas from wells and field gathering systems.

Natural Gas Transmission & Storage

Lubricants for compressors handling treated natural gas in pipelines, underground storage and transmission infrastructure.

Cryogenic Compression

Lubricants for very-low-temperature process gas and cryogenic compression applications.

Sour Gas Compression

Lubricants for gas streams containing significant H₂S, CO₂ and other acid-gas components.