Influence Law of Pulse Current Cathodic Protection Parameters

Simulation system of oil well casing was established in NaCl solution, coupon test method was used to investigate the effect of square wave pulse current parameters (frequency, duty cycle) on protection effect of pulse current cathodic protection. The results showed that with the increase of square wave pulse current frequency and duty cycle, the cathodic polarization potential distribution curve negatively shifted gradually, the polarization amplitude increased gradually, the effective protection depth was obviously prolonged, the protection current was smaller in average. To improve the protection effect and reduce the current consumption, the middle range of duty ratio, high frequency and appropriate distance between the cathode and the anode should be chosen.