scope:

This standard presents acknowledged procedures for the control of external corrosion of steel well casings by applying cathodic protection. This standard is intended to be a guide for establishing minimum requirements for corrosion control when cathodic protection is practical and cost-effective.

This standard does not designate practices for specific situations. The complexity of some casing spacing, subsurface proximity to other casings, and environmental conditions preclude standardizing the application of cathodic protection. Deviation from this standard may be warranted in specific situations, provided those in responsible charge can demonstrate that the objectives expressed in this standard have been achieved.

This standard does not include corrosion control methods based on chemical control of the environment.

This standard applies only to well casing exteriors and not to internal corrosion, or to corrosion of other surface or downhole equipment.

The provisions of this standard should be applied under the direction of competent persons knowledgeable in the physical sciences, principles of engineering, and mathematics. They may have acquired knowledge by professional education and related practical experience and should be qualified to practice corrosion control for well casings by the use of cathodic protection. Such persons may be registered professional engineers recognized as being qualified as corrosion specialists in the appropriate fields of corrosion control by NACE International. Their professional activities should include suitable experience in well casing corrosion control practices.