3S4: Case Study: Gas Turbine Varnish Removal by Chemical Wash: Challenges, Observations and Recommendations

Zulkiflee Ismail, Manager, Delta Engineering Services


Delta Engineering Services have been engaged by PGB to conduct chemical wash to remove varnish build up on the internal surfaces of the COGEN GTG LO circulation system. Collected contaminant are to be drained out together with the spent oil. PETRONAS Gas Berhad (PGB) is a leading gas infrastructure and utilities company with core businesses in gas processing, gas transportation, regasification, and utilities. PGB owns, operate and maintain 2 gas processing complexes, Gas Processing Kerteh (GPK) and Gas Processing Santong (GPS) with total gas processing capacity of 2,060 mmscfd. Subject facilities are cogeneration (COGEN) plants which consists of 2 unit Caterpillar Turbomach’s Solar Titan 130 gas turbine generators at GPK and another 2 unit at GPS.
The summary scope of work is to remove varnish from GTG at GPK and GPS COGEN to contractual requirement for the 4 unit GTG. Method of varnish removal shall be by chemical wash using Kluber Varnasolv and kidney loop filtration using Parker filter cart and work shall include washing, flushing, draining, inspection, packing for disposal of spent oil and fill-up of the COGEN lubrication oil system with new oil.

Varnish removal by chemical wash method:
1. Reason why chemical wash was selected
2. Methodology
3. Results, observations and way forward


Mr. Zulkiflee has 25+ years’ experience in the oil & gas industry in various roles and capacity. He started his career at PETRONAS Refinery as a maintenance engineer in Kerteh, Terengganu. His last role was as Regional Technical Manager covering Southeast Asia for a subsidiary of a Singapore public listed engineering company involved in fabrication of pump skid, pipeline pig signaler, pipeline leak repair clamp with focus on subsea repair and RO watermaker before joining Delta Engineering Services Sdn Bhd in 2015.

At Delta he is responsible in overseeing and growing its oil and fuel filtration and lubrication business in Malaysia with focus on East Coast region covering both upstream and downstream clients such as PETRONAS Carigali Sdn Bhd, Carigali Hess Operating, ExxonMobil, PETRONAS Gas Berhad to name a few. Supported by technical advisors from principal manufacturers represented by Delta in filtration and lubrication business, Delta have successfully completed lubrication oil filtration and circulation line chemical cleaning projects.