Analysis Of Impurity Composition And Improvement Of Filter Element Structure In Coalbed Methane Pipeline

In the process of coalbed methane gathering,solid and liquid impurities are potential danger of coalbed methane gathering and transportation system due to their damages to pipelines,compressors,instruments,valves etc.In order to remove these impurities efficiently,it is necessary to analyze the components of impurities in the pipeline,finding out the source and developing a suitable filter elements.This dissertation uses a variety of component analysis methods to analyze the impurity components.Each analysis method is authenticated by each other,and the components of the impurities at each sampling point are obtained quantitatively and qualitatively.At the same time,based on the fact that there are a lot of magnetic substances in the impurities,the structure of filter element is improved by designing framework,inlaying permanent magnet and arranging filter material.The improved filter element and the on-site filter element were tested in the laboratory and the gas gathering station respectively to compare the filtration performance.The results show that:1)Components of impurities at each sampling point are different.Generally speaking,samplings of the gas gathering station near the gas production well contain a small amount of sand gravel,soil and other components(about 10%);due to the influence of gas qualities of each well,the impurities in some gas stations have more pipeline corrosion products Fe CO₃ and Fe S caused by acid gases such as CO₂ and H₂S;the solid impurities are mainly pipeline corrosion,but less than65%;2)Under the laboratory condition,filtration efficiency of dust(particle size?1?m)of improved filter element is 99.99%,and the filtration efficiency of liquid drop(particle size?0.3?m)is 99.93%.Both efficiencies are higher than that of the original filter element,also meets the requirements of relevant standards;3)under the field condition,the efficiency is improved by 19.53%.The results provide suggestions for the analysis methods of impurities in coalbed methane,and a reference direction for the purification of coalbed methane.