The Effect Evaluation Method Research Of Well Casing Cathodic Protection Based On The Pulse Current

The outside corrosion of well casing is a form of casing failure,cathodic protection technology is one of the inhibiting metal corrosion method.Related research show that the pulse current protection technology has a more uniform distribution of current,,lower energy consumptiocathodic n and more advantages.however,pulse current cathodic protection technology has not thorough application in oil well casing,and evaluation and assessment methods for its protective effect rarely.First,we studied the theory of the well casing corrosion principles and protection methods,the principle of pulsed current cathodic protection technology,the criterion of protective effect.proposed a method of pulsed current cathodic protection effect evaluation which based on single well casing model.followed by this model,It is concluded that compared with dc current cathodic protection,the pulse current cathodic protection potential attenuation trend is gentle,protective effect is better,and has a deeper depth in a relatively stable protective potential scope,Thus there are certain research value.through the experiment,we investigated the influence of basic parameters of simulated well casing pulse current cathodic protection.Obtained when the output power is constant or change very small,pulse current cathodic protection parameters select 3500 Hz or higher frequency,50% or moderate duty ratio,the cathode can be better protected,and current consumption is lower,we also should select a moderate range of anode distance as far as possible.Finally,we evaluated the effect of modeling and simulation,By analyzing the well casing pulsed current cathodic protection of the Process parameters,system settings,protection,etc,summarized the well casing pulse current cathodic protection effect evaluation methods in actual environment.