Numerical Simulation and Application of Internal Anticorrosion Parameter Optimization of Oil Field Temperature Resistant Anode Casing

Aiming at the problem of internal corrosion casing damage in Jurassic oil wells in oil fields, a temperature-resistant anode casing internal corrosion protection technology was developed with the goal of long-term protection of key corrosion sections. According to the relevant specifications of cathodic protection, four sets of simulation tests were built indoors to carry out 720 h casing polarization performance test. The effects of casing coating, medium solution and temperature on the protection effect of sacrificial anode were investigated, and the theoretical calculation and numerical calculation results were verified. The results showed that the tubing did not affect the protection of the casing by the tool. The increase of anode number had no effect on the protection potential distribution and output current. With the increase of anode spacing, protection potential decayed faster. When protection potential of anode midpoint reached -0.8 V, the distance was maximum effective protection distance. With the increase of sacrificial anode size, the effective protection distance did not change significantly. In the oilfield environment, the anode life was about 2-4 a. Through field performance optimization and structural improvement, 402 wells were implemented in total. The corrosion rate was reduced from 0.38 mm/a to 0.19 mm/a, and the validity period was more than 720 days.