Multihot Fluid Corrosion and Protection of Petroleum and Natural Gase Mining and Gathering System

The downhole and ground work conditions were simulated to test the influence of CO2 corrosion on ground pipelines and downhole pipe strings under high temperature and high pressure dynamic experiment conditions.And the CO2 in multihot fluid was genetated by enhanced oil recovery facility which was propelled by rocket dynamics.The results show that the maximum corrosion rate of N80 oil tube steel reached 0.459 mm/a under the pressure of 10 MPa at 60 ℃ for 24 h.And under the condition of 1 MPa and 50 ℃,the corrosion rate of A3 steel was 0.161 mm/a due to the influence of multihot fluid.The selection of corrosion inhibitors show that the effect of 9BS inhibitor was obvious,the corrosion inhibition rate was 94.59% at the dosage of 35 mg/L.