This paper presents a thermodynamic analysis of a gas transmission system consisting compressor stations and pipeline sections. It has been assumed that the compressor station comprises a gas turbine-driven compressor and a gas cooler, and the irreversibility of the processes associated with the gas transmission was investigated. The exergy method was used to determine the amount of work supplied to the components of the pipeline system and the amount of work that is lost during the gas transmission. For the case study, the Yamal-Europe pipeline is chosen. In this study, a nonisothermal, steady-state gas flow model was used for comparing the performance of the gas transmission system under different cooler operating set points. The pipeline flow and the compressor station processes were governed by the equations which include real-gas model based on virial equation of state. (c) 2010 Elsevier Ltd. All rights reserved.