Analysis And Research On Safe Operation Of Moisture Pipeline Flow In Sichuan Northwest Gas Mine

The corrosion characteristics of moisture gathering and transportation pipeline have the important effect on the safe and economical operation of the pipeline.In this paper,according to the research of three typical wet gas gathering and transportation lines that located in the northwest Sichuan gas field,carried out a study of flow corrosion and hydrate analysis,and obtained the corrosion law of the pipeline and the formation characteristics of the hydrate.The results of the study have some theoretical guidance on the safe and economical operation of the pipeline.Through the numerical simulation analysis,when the moisture gathering and transportation pipeline stably operates,the running pressure drop in the pipeline is slightly changed,and the flow pattern of upwelling section is slug flow,and the downhill section is stratified flow.The whole line pressure drop is affected by the terrain change.The corrosion rate of the pipeline is affected by the partial pressure of the acid gas and the Liquid Holdup,and for different pipeline,the location of maximum corrosion rate is different.With the increase of the running capacity,the pressure drop of the pipeline is fluctuating,and the variation law is affected by the degree of terrain fluctuation.The total amount of effusion in the pipeline is obviously decreased,and the position of the effluent changes,which affects the change of the maximum corrosion rate position.Make an analysis of unsteady operation of moisture gathering and transportation pipeline,with the continuous running time of the pipeline,the effluent in the pipeline increases,the running pressure drop increases,the pH value decreases,the corrosion rate in the pipeline increases,and after the different settling time,The pipeline operating pressure,temperature,pH value and corrosion rate and otherparameters tend to be stable.Programming and calculating the pressure drop and the temperature distribution along the pipeline according to the different environmental conditions and the gas composition,obtained the conclusion that the lowest temperature of the whole line of the three pipelines is in mid-February,and obtained the corresponding temperature distribution curve;drawing hydrate formation curve,combined with the temperature distribution,obtained three moisture gathering pipeline will not generate hydrate.It is suggested that the gas gathering and transportation pipeline in northwest Sichuan should be cleaned once a year,and the operation time should be choosed from the end of January to the beginning of February to avoid the occurrence of hydrate formation and clogging the pipeline accident and ensure the safe operation of the moisture gathering pipeline.