Study On Uniform Distribution Method Of Corrosion Inhibitor In High Temperature And High Pressure Gas Collecting

With the development of natural gas, pipelines transportation industry has been more prosperous than before. The requirement of pipelines material has been improved gradually for coping the sever environment of natural gas exploration. As its convenience,carbon steel pipes have still been at the top position in the market even though there are more options for the selection of pipes material. Comparing to stainless steel material pipes, carbon steel pipes have been more vulnerable to fail if the natural gas would contain corrosive impurities such as CO2and H2S. Thus, it should be valued at the corrosion prevention of the pipe. It is common to see that inhibitor anti-corrosion technology has been applied widely in the corrosion prevention of the pipes. It has focused on absorption-filming inhibitor for the multiple choices of inhibitor.The chemical properties ofabsorption-filming inhibitorhave been studied for a long time, such as its characteristics, mechanism and concentration. The flow and distribution of it has been studied uncommonly in the pipes, but it could play an important role on the prevention of pipes. From the perspective of its injection process, it has been illustrated mainly that the flow and distribution of absorption-filming inhibitor in the pipeand how to makeitdistribute equally in the pipe, which basing on the background of sever CO2failure gas field.It has set up three types of model to solve the questions above by the application of ANSYS-CFX. They are tee-model, reducer-tee-model, and90°elbow-model. According to the analysis results, three conclusions have been found out. Firstly, the volume fraction of inhibitor on the top of the pipe is the least in the tee-model, and the parts around the pipes top are also less than the other parts of the pipe, where the sever CO2failure happened. Secondly, it is supposed that internal turbulent flow can make inhibitor distribute equally.Lastly, the distribution in the vertical pipe is the best;90°elbow’s distribution is worse than the vertical pipe; the horizontal pipe is the worst.According to the above analysis results, blades-model has been made to improve the distribution of inhibitor in the horizontal pipes which could make equal distribution nearly. It has been proven that the location of inhibitor injection should be placed on the vertical pipe in the horizontal-Ⅰ-model. As the horizontal-Ⅱ-model, it should be on the first horizontal pipe before the first90°elbow. After analyzing different velocity of inhibitor injection,0.6m/s、1.2m/s、2.4m/s、4.8m/s、9.6m/s and12m/s,12m/s is the best to make it distribute equally. The distribution effect will be better if the average diameter of inhibitor drops will be less.