Ways for optimizing and increasing reliability of centrifugal compression systems in oil and gas industry: Case study in Sultanate of Oman

Rotating equipments reliability and performance have evolved in the recent decays. Manufactures continue to produce more sophisticated machines. Those equipments form a central part of any oil and gas plant. Compressors in particular considered being a major investment for any company. For any operator, keeping the compressors performance and reliability is a very major task which requires an intense OPEX spending in some cases. This study was conducted to focus on the common issues which are related to centrifugal compressors in Oil and Gas Industries with the aim to increase the reliability and performance of this type of compressors and to form a kickoff for compressors low performance root cause analysis. Also, it will serve as a quick reference for engineers and operators to troubleshoot and optimize compression system. The common compressors issues identification and short listing of this study was not limited to literature review instead a detailed analysis of an existing centrifugal compressor system was carried out and common issues were reported. These issues were shortlisted to focus only on the process related aspects which are liquid carry over, surge, improper system configuration, variation on inlet gas properties and pressure impacts on the performance. An existing compression system has been selected to study the effects of the listed issues. The performance and reliability of these compressors were checked and monitored for the last three years. To meet the objective of this study, a detailed analysis was conducted to solve these issues and optimizing the system. The study includes theoretical analysis and field troubleshooting and trials). Theoretical aspects of the work with regard to the compressor efficiency, power consumption as well as other important issues are examined based on thermodynamic analysis of the systems. The theoretical analysis concluded that the reliability and performance of the compressor system can be increased through a number of recommendations including optimization of the suction and discharge pressure, continuous process monitoring, enhancing inter stage scrubbers' efficiency and maintaining the gas molecular weight through compressors stages. In addition, some recommendations are given which are applicable during the design stage such as recycle line location, drain system design, seal system design and scrubbers internals accessibility. The recommendations of the theoretical analysis are under long term field trials to ensure their applicability and sustainability. The results from this study are projected to be generalized for similar type of compression system in the industry. This paper will be of interest to anyone who designs or operates multistage compression systems.