Some Aspects of Prevention of Crystalline Hydrates Formation at Gas Distribution Stations

Abstract

The existing methods for natural gas dehydration both in fields and at compressor stations cannot always provide standatdized values of natural gas dehydration. The analysis of operation of gas distribution systems shows that dehydration units are improperly placed and are often installed out of condensation and freezing zones. This is due to the lack of consideration of phase transitions impact in gas throttling on its temperature condition. Due to insufficient natural gas dehydration, crystalline hydrates can be formed on wellbores, distribution lines and main gas pipelines and at its reduction, disturbing the operation of the equipment of compressor stations, gas distribution stations, deranging instrumentation and automation. The issues of reliability of gas pipeline systems considering the formation of crystalline hydrate plugs in pipelines have been studied. The analysis of the methods and devices preventing hydrates formation and eliminating existing crystalline hydrate plugs has shown that to provide normalized parameters of the transported gas it is necessary to perform additional water vapor, condensate drops and crystalline hydrate particles removal from natural gas at gas distribution stations during winter months. Currently applied methods used to deal with crystalline hydrate plugs in main gas pipelines require significant expenses and do not effectively ensure the reliability of pipelines operation. An energy-efficient design of an integrated treatment unit which provides an additional natural gas treatment at GDS, increases the reliability of gas pipelines protection against hydrate blockage and improves the efficiency of gas supply systems as a whole have been proposed at the Department of Heat and Gas Supply and Ventilation of the SWSU.