Common Anti-corrosion Methods for Offshore Tubing and Casing

The corrosion of oil casing is related to the partial pressure of corrosive gas, ambient temperature, water content, salinity, flow rate, pH value and other factors. The corrosion characteristics of oil and gas fields in different sea areas are different. The temperature of the developed oil layers of most oilfields in the Bohai Sea is between 60? and 150?, and the partial pressure of CO2 is between 0 and 1.5MPa. The pH value of the formation water is basically above 7.5, and the Cl- of the formation water is generally low, basically below 5000 ppm. The partial pressure of CO2 in gas wells in the East China Sea is between 0.3 and 1.5 MPa, and the temperature is basically between 100? and 150?. The pH value of the formation water is basically above 7.5, and the Cl- of the formation water is generally low, basically below 5000ppm. The temperature of the development zone in the eastern South China Sea oilfield is mostly between 65°C and 132°C, and the partial pressure of CO2 is mostly lower than 0.4MPa, with the highest being 1.68MPa. Some oil fields contain high levels of hydrogen sulfide. The pH of the formation water is basically below 7, and the Cl- of the formation water is relatively high, between 15,000 and 25,000 ppm. The development horizon temperature and CO2 partial pressure of the western South China Sea oilfield are mostly distributed in the area of 59?