This document provides information on methods suitable for assessing the likelihood of leakage due to external corrosion of well casings and to evaluate the need for cathodic protection, as well as methods of providing cathodic protection to the external part of these wells in contact with the soil. It also defines requirements for monitoring of performance of CP systems.
Onshore and offshore wells are included in the scope. However, for offshore wells where protection is provided by anodes on the wellhead structure, it is recognized that it might not be practical to achieve full protection of well casings.
This document applies to any gas, oil or water well with metallic casing, whether cemented or not.
However, in special conditions (shallow casings: e.g. 50 m, and homogeneous soil), EN 12954 can be used to achieve the cathodic protection and assess its efficiency.
The general requirements of EN 12954 apply; this document details additional, specific, requirements for CP of well casings.
This document applies to production and injection wells. References later in this document to production also apply to injection.