Surge Mapping of Compressors to Enhance Energy Efficiency and Integrity

Abstract ADNOC Gas Processing Ruwais NGL Plant carried out a field surge testing of one of its Centrifugal type Refrigeration compressor units in order to accurately evaluate the real surge points. Centrifugal compressors used in Gas processing plants are critical machineries consuming significant amount of energy. Unavailability of the compressor due to any failure will cause revenue loss and downtime to the plant operators. Often failure of the compressor system happens due to unstable operation caused by surge. Manufacturers build surge control systems to protect the machinery during the project stages through simulation. However, inaccurate surge map or shifting of surge control lines during plant operation may result in energy losses or machinery damage. Surge test establishes the baseline for machine to help understand future issues better, for machinery protection, safe operation and efficiency. Performing high risk surge testing activity in a safe and successful manner during plant operation and re-mapping resulted in optimal utilization of existing assets without the need for costly upgrades. This innovative technique can lead to impressive improvements and benefits on equipment integrity, performance, energy efficiency, emissions and profitability. This best practice has great potential for transferability across Oil & Gas industry as such compressors and control systems are common across the industry. This paper highlights the methodology of accurate mapping of surge control lines in a safe manner during plant operation to enhance energy efficiency of the machine by reduced gas recycles and to enhance machine integrity by avoiding early surge possibilities.