Review of Gas Compression System Design and Operating Efficiency at the Escravos Gas Processing Plant, Delta State, South South Nigeria

Gas compression is a fundamental process unit in gas processing plants, and its design efficiency and operational reliability directly determine both the commercial output and energy consumption of natural gas processing facilities. This study reviews the design basis and operating efficiency of gas compression trains at the Escravos Gas Processing Plant in Delta State, South South Nigeria, operated by Chevron Nigeria Limited under the Escravos Gas to Liquids project framework. Technical performance data for centrifugal compressor trains in the lean oil absorption and fractionation sections were collected from plant operations reports spanning 2020 to 2023. Isentropic and polytropic efficiencies were calculated for each compression stage using measured suction and discharge pressures, temperatures, and gas flow rates. Analysis indicates that three of the six assessed compressor trains operate at polytropic efficiencies below 78 percent, compared to design efficiencies of 83 to 86 percent, primarily due to impeller fouling from condensed heavy hydrocarbon carry-over. Performance degradation curves are constructed for each affected train, and the revenue impact of efficiency losses is quantified at approximately 12 million USD annually in under-utilised processing capacity. Maintenance scheduling recommendations are provided, including on-line water washing intervals and impeller inspection trigger criteria. Keywords: gas compression, isentropic efficiency, Escravos Gas Plant, Delta State, compressor fouling.