The Development Of Natural Gas DRAs And Drag Reduction Performance Test

With the rapid development of the world economy, natural gas has been receiving increasing attention in many countries because of its great development potential and less pollution .However, natural gas producing area is relatively dispersed ,and far from the main consumer ,it must be transported by natural gas pipelines.For pipeline transportation of natural gas,the roughness of inner surface of pipeline can be caused by machining accuracy,scraping mark,pipeline corrosion and friction corrosion which was engendered in pipeline processing or after being put into use in particular; it will result in the pressure loss in the process of natural gas transportation; Therefore, the main means to increase gas flow is to reduce roughness of gas pipeline so as to reduce the pressure loss.At present, pipeline coating drag-reducing technology is widely used to reduce the roughness at home and abroad , but the construction equipment of pipeline coating drag-reducing technology is complex and the expense is high; furthermore, the pipeline coating will keep off with time, as a result, the drag-reducing effects will decrease with time or even have a negative effects, while the original non-coated pipe, due to issues such as construction costs, could not be implemented.The gas DRAs technology can overcome the disadvantages of the inner coating technology and has wide application foreground. The chemicals with surface activity s were periodically injected into gas pipeline, the polar terminal was adsorbed onto the pipe iron wall surface to form the elastic film, so the pipe wall roughness was accordingly reduced and the drag-reducing effect was obtained.Preliminary study of our subject group in the research of DRA and the mechanism of drag reduction has made some progress,primarily we have developed a total of more than 10 kinds of gas drag-reducing agent,all of which have good drag-reducing potential, Some have been tested in the drag reduction test loop, and achieved the required drag reduction rate.This paper expatiated the current situation and development trend of gas pipeline,and analyzed mainly the innner coating and DRA technologies in gas pipeline. Based on drag-reducing mechanism of natural gas DRA, combined with the results of the preliminary work of our subject group, long-chain alkyl amide imidazoline was studied , through the online IR tracking on its synthetic process to study the relation of the reaction time and product yield as well as its reaction mechanism,and the final product was characterized with the static infrared, comparing with the online IR. The film-forming situation of the product compounds on the surface of the steel sheet was observed by SEM.We consulted with the literature to form the combination of the product with other compounds.The evaluation method of the drag-reducing property was established; we tested the drag-reducing property of synthetic product and its combination , analysed test results and gave the suggestion to eliminate the systematic error.