Corrosion on well casings can come in the form of generalcorrosion or as more localized corrosion in areas where elementssuch as aquifers, soil conditions or salt caps can accelerate thecorrosion rate. Cathodic protection has been used successfully fordecades as a means to protect casing strings in production anddisposal wells.
Factors such as well depth, casing size, soil corrosivity andelectrical continuity must be considered during the designprocess. Anode systems that are sized or installed incorrectlycan degrade rapidly, leading to premature depletion, requiringreplacement in order to adequately manage active corrosion.
Proper protection of well casings can provide years of trouble-freeoperations and minimize required maintenance. Inspectionof the casings is generally expensive, with access for inspectiontools often limited by surface equipment and the casing hanger. Apurpose-built cathodic protection system prevents corrosion andtypically represents 1 to 3 percent of the cost of a well. Once installed, ongoing monitoringof the cathodic protection system can be performed withoutproduction interruption.
With over 40 years of experience in designing and installingsystems that provide long-term protection, Corrpro’s well casingsolutions meet both NACE and API guidelines and are very similarto conventional deep anode groundbed (DAGB) systems.
Wells withadequate cathodic protection have far fewer leaks and failuresthan unprotected wells.