Rerearch On The Corrosion Meehanism And Corrosion Protection Tehnology For The Key Equipment Of Natural Gas Processing Plant In Yulin Gas Field

In the process of natural gas exploiting in Yulin gas field, the life of facilities were impacted by corrosion, which posed threats to the operation that required running safely. Therefore, this project studied the current corrosion situation, corrosion mechanism and corrosion protection technology for the equipment of natural gas processing plant in Yulin gas field. Followings were the main study contents and results:The project was based on the use of equipment of natural gas processing plant in Yulin gas field. It studied the current corrosion situation of the representative distillation column and coarse filters. Through the application of grey correlation analysis and orthogonal test method, the main factors of corrosion were found to be pH、the mineralization and HCO3-. Meanwhile, types of corrosion and corrosion product research illustrated the corrosion of the distillation column and the coarse filters were caused by electrochemical corrosion with the coexistence of the high mineralization (main factors of corrosion of Cl-)、the acid gas of high CO2and the dissolved oxygen, and CO2was the predominant corrosion element overall. Based on reasons and laws of corrosion, a series of inhibitors of "switchable" rosin-based imidazoline were synthesized for natural gas exploiting in Yulin gas field. Under simulated field conditions, this paper had explored inhibitors by combining the method of static coupon weightlessness and electrochemical workstation. The results showed that the corrosion inhibition efficiency was over80%and the satisfied anticorrosive results were achieved. The corrosion inhibiting mechanism of these compounds was discussed through analyzing the electrochemical data, which showed that this inhibitor belonged to the hybrid control corrosion inhibitor that based on cathode suppression.