ExxonMobil, with a US office in Texas, has released best practice guidance for oil and gas operators in selecting environmentally acceptable lubricants that help limit environmental impact without compromising performance. When purchasing such lubricants, ExxonMobil suggests considering three things:
1. Lubricant base stock: Those based on synthetic esters perform well across a wide range of temperatures, have a high viscosity index, possess good lubricity, provide excellent corrosion protection and have high oxidative stability.
2. Lubricant compatibility: Most based on synthetic esters are compatible with mineral oils, so long as less than 2% of the previous oil change remains. Using a compatible lubricant when converting from mineral oil products will also reduce the need for solvent flushing.
3. Lubricant performance: Those based on synthetic esters possess very good low and high temperature properties and can have good hydrolytic stability depending on the ester.