Operating Strategy of Oil - Flooded Screw Compressor Experiencing Oil Dilution in Fuel Gas System

Abstract

Two 2,900 kW (3,900 hp) oil – flooded twin screw compressors deliver fuel gas from sour gas processing system to Gas Turbine Generators (GTG) at Banyu Urip oil production facility in Indonesia. The compressors operate with Polyalkylene Glycol (PAG) lubricant, which is hydroscopic. Water content in process gas that has direct contact in the compressor may contaminate the PAG lubricant and thus make it necessary to control lubricant water content to prevent reduction of viscosity. While over contamination of the PAG lubricant by water may cause costly damages, the solution will also require significant downtime and high capital expense. This case study optimizes compressors operating strategy to avoid significant downtime and cost of improving the sour gas processing system. Controlling hermodynamic parameters around the compressors maintain acceptable lubricant water content and viscosity until upgrades could be made in the gas processing system.