Cathodic protection for deep well

[waterwellguy]

I am designing a deep injection well and would like to provide cathodic protection to protect against casing corrosion. The well will have casing to 2,750 feet. I will be using seamless, half-inch wall, mild steel casing. Any real challenges to protecting the entire casing string? More information just in case it is needed: fluid velocity abut 5 feet per second, fluid is treated effluent from the wastewater treatment plant, chlorides are around 1,200 mg/L, temperature is around 80 degrees.

 

[YLWEA]

I assume you already know that the CP won't protect the inside of the casing where the wastewater is. The OD of casing is routinely protected by CP, although others are better suited to provide details of things to consider and how to do it.

 

[unclesyd]

I would highly recommend that you get with a consultant/company that has experience and references in this area. I think they will save you a lot of grief and money in the long run. There are numerous expensive traps in deep well injection design and operation.

We have 3 (1700'-1999') and you would believe how many hours in design and permitting went into each. Ours are all SS, both the casing and process pipe, and a chromate solution in annulus.