Gas compressor oils must be inert to the gas with which they are in contact.
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Gas Compressor Oils
Gas compressor oils must be inert to the gas with which they are in contact. In the case of hydrocarbon gases, the oil must not absorb it to any great extent, as this will change the lubrication properties.
They have a similar job to perform as an air compressor, but often with a more hazardous or aggressive gas. Operating temperatures are generally much lower than for air compressors.