Research In Gathering Pipeline With CO2Corrosion And Material Selection Technology

In this paper, the CO2corrosion behaviors of the gathering pipeline materials (13Cr,06Cr13,22Cr,316L, L360,16Mn) were studied. In the first stage of laboratory study, by simulating water medium, corrosion behaviors of the materials were researched in different partial pressure of CO2, including the Cl-environment. The results show that, when the partial pressure of CO2was IMPa and the concentration of Cl-was1000mg/L,22Cr and316L did not occur obvious corrosion,1Cr13appeared moderate corrosion,06Crl3, L360and16Mn occurred extremely serious corrosion; When the partial pressure of CO2was5MPa and the concentration of Cl-was10000mg/L,22Cr and316L occurred slight corrosion,13Cr was seriously corroded, L360and16Mn occurred extremely serious corrosion, yet glass fiber reinforced plastic was not seen obvious corrosion, and the corrosion rate of material in the liquid phase is generally higher than that in the gas phase. In the second stages of laboratory study, by using field liquid medium (YK6H and YK9X gas wells), corrosion behaviors of the materials were researched in different partial pressure of CO2in the gas-liquid two phase. The results show that, in field liquid medium of YK9X well,22Cr and316L occurred slight corrosion,13Cr was moderate corroded,16Mn and L360occurred extremely serious corrosion; in field liquid medium of YK6H well,22Cr and316L appeared slight corrosion,13Cr occurred moderate corrosion,16Mn and L360were extremely serious corroded, and the corrosion rate in the gas phase was lower than that in the liquid phase, moreover the corrosion rate in high CO2partial pressure is higher than that in low CO2partial pressure. Finally, in this paper, on the basis of laboratory study, the real gathering pipeline of oil field were experimented. The results show that:high-pressure glass fiber reinforced plastic pipe can be used in serious corrosion area, dual-metal composite pipe (lined with316L) and13Cr are suitable in some areas of the serious corrosion,16Mn and L360are not suitable for the gathering pipeline containing CO2.