CEN/TC 219/WG 1 - Cathodic protection of buried and immersed metallic structures

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.

This document describes the general principles for the implementation and management of a system of cathodic protection against corrosive attacks on structures which are buried or in contact with soils, surface fresh waters or underground waters, with and without the interference of external electrical sources. It specifies the protection criteria to be achieved to demonstrate the cathodic protection effectiveness.
For structures that cannot be electrically isolated from neighbouring influencing structures, it may be impossible to use the criteria defined in the present document. In this case, EN 14505 will be applied (see 9.4 "Electrical continuity/discontinuity").
To assist in forming a decision whether or not to apply cathodic protection the corrosion likelihood can be evaluated using Annex A. Annex A summarizes the requirements of EN 12501-1 [2] and EN 12501-2 [3].
Cathodic protection of structures immersed in seawater is covered by EN 12473 and a series of standards more specific for various applications.
Cathodic protection for reinforced concrete structures is covered by EN ISO 12696.
This document is applicable in conjunction with:
-   EN ISO 15589-1 for application for buried or immersed cathodically pipelines,
-   EN 50162 to manage d.c. stray currents,
-   EN ISO 18086 to manage corrosion due to a.c. interference from high voltage power sources and a.c. traction systems,
-   EN 13509 for cathodic protection measurement techniques
-   EN 50443 to manage protection for touch and step voltage.

ISO 15589-1:2015 specifies requirements and gives recommendations for the pre-installation surveys, design, materials, equipment, installation, commissioning, operation, inspection, and maintenance of cathodic protection systems for on-land pipelines, as defined in ISO 13623 or EN 14161 for the petroleum, petrochemical, and natural gas industries, and in EN 1594 or EN 12007‑1 and EN 12007‑3 used by gas supply industries in Europe.
All contents of this part of ISO 15589 are applicable to on-land pipelines and piping systems used in other industries and transporting other media such as industrial gases, waters, or slurries.
ISO 15589-1:2015 applies to buried pipelines, landfalls of offshore pipeline sections protected by on-shore based cathodic protection installations, and to immersed sections of on-land pipelines such as river or lake crossings.
ISO 15589-1:2015 specifies requirements for pipelines of carbon steel, stainless steel, cast iron, galvanized steel, or copper. If other pipeline materials are used, the criteria to apply are defined under the responsibility of the pipeline operator.
ISO 15589-1:2015 does not apply to pipelines made of reinforced concrete for which EN 12696 can be applied.
NOTE          Special conditions sometimes exist where cathodic protection is ineffective or only partially effective. Such conditions can include shielding (e.g. disbonded coatings, thermal-insulating coatings, rocky soil, etc.) and unusual contaminants in the electrolyte.

ISO 15257:2017 defines five levels of competence (detailed in Clause 4) for persons working in the field of cathodic protection (CP), including survey, design, installation, testing, maintenance and advancing the science of cathodic protection. It specifies a framework for establishing these competence levels and their minimum requirements.
Competence levels apply to each of the following application sectors:
-      on-land metallic structures;
-      marine metallic structures;
-      reinforced concrete structures;
       inner surfaces of metallic structures containing an electrolyte.
These application sectors are detailed in Clause 5.
ISO 15257:2017 specifies the requirements to be used for establishing a certification scheme as defined in ISO/IEC 17024. It is not mandatory to apply all of the levels and/or application sectors. This certification scheme is detailed in Annexes A, B and C.

This European Standard defines the conditions necessary for an effective application of the cathodic protection method to mitigate corrosive attacks on the external surfaces of above ground storage steel tank bottoms in contact with soil, cushion or foundations.
This European Standard specifies the requirements for the design, implementation, commissioning, operation and maintenance of such a cathodic protection system.
This European Standard applies both for new and existing tanks.
NOTE 1   This European Standard is not applicable to reinforced concrete above ground storage tanks for which EN ISO 12696 applies.
NOTE 2   Detailed information concerning measurement techniques of cathodic protection given in EN 13509 are referred to in the present standard.
NOTE 3   Cathodic protection of internal surfaces of above ground storage steel tanks storing waters is addressed in EN 12499.
NOTE 4   Cathodic protection of external surfaces of buried tanks is addressed in EN 13636.

This document should be used for the cathodic protection of complex structures. It is applicable to structures, which are to be cathodically protected, but cannot be electrically isolated, whether for technical or safety reasons, from foreign metallic structures situated in the same electrolyte as the structure to be protected. Such a structure is referred to as a "complex structure".
This document is not applicable to structures that can be protected in accordance with EN 12954. When contacts with foreign structures or defective isolation from foreign structures exist, but can be corrected, the EN 12954 should be used instead of this document.  As an example pipeline network distribution systems are not considered to be complex structures
It is assumed in this document that the design, installation, commissioning, inspection and maintenance are entrusted to adequately trained, experienced, competent and reliable personnel in order to achieve effective and efficient cathodic protection.
Annexes A and B show the principle scheme of a complex structure with examples.

This document specifies the principles for the implementation of a system of cathodic protection against corrosive attacks on buried metal tanks and associated piping.
This document specifies conditions and parameters to be met in order to achieve cathodic protection, as well as rules and procedures for the design, installation, commissioning and maintenance for the protection of buried metal tanks and associated piping.
This document is applicable to the external surfaces of buried metallic tanks and associated buried piping.
NOTE   The protection of internal surfaces is covered by EN 12499.
This document is applicable to buried tanks and associated piping, even if they are earthed by their own local earthing device, which are electrically separated from any general earthing systems and other buried structures.
Therefore tanks which are covered by the present document include:
- industrial storage tanks, irrespective of their dimensions and the nature of the stored medium (liquid or gas, flammable or not, toxic or non-toxic, polluting or not);
- tanks used at petrol stations and on domestic or commercial premises, which contain flammable liquids or gases or polluting substances.
This document is not applicable to:
- above-ground storage tank floors in contact with the ground;
- reinforced concrete containers;
- buried storage tanks that are electrically connected to the whole or a part of an industrial complex;
- buried storage tanks electrically connected to any general earthing systems.
NOTE   Cathodic protection of the last two types of tanks is covered by prEN 14505.
Measurement techniques are described in detail in EN 13509.

This European Standard deals with the cathodic protection against corrosion of buried or immersed metallic structures, detailing the measuring methods to be used for assessing the effectiveness of cathodic protection as well as the measurements and measures taken to monitor cathodic protection during operation.
Throughout the text, the measurement techniques are described primarily for pipelines.
However, they are sufficiently general to apply to other kinds of buried or immersed (except offshore) structures.
General principles with regard to cathodic protection are described in EN 12954. Other measurement methods specific to particular cases are described in other European Standards e.g. prEN 50162.

This European Standard specifies methods used to evaluate the external corrosion hazards of well casings, as well as cathodic protection means and devices to be implemented in order to prevent corrosion of the external part of these wells in contact with the soil.
This European Standard applies to any gas, oil or water well with metallic casing, whether cemented or not.
However, in special conditions (shallow casing: e.g. 50 m, and homogeneous soil), EN 12954 can be used to achieve the cathodic protection and assess its efficiency.
This European Standard also describes techniques allowing determination of the current required for protection and ensuring correct operation of the cathodic protection devices installed.

This standard describes the general principles which allow the implementation of a system of cathodic protection against corrosive attacks on buried or immersed metal structures. This standard indicates parameters that should be met to achieve cathodic protection as well as rules and procedures that should be followed for design, installation commissioning and maintenance of the protective system. The phenomena of electrochemical corrosion which may occur on a metal structure when in contact with an electrolyte may become worse due to currents from external electric sources.

This European Standard is applicable to buried cathodically protected metallic structures that are influenced by a.c. traction systems and/or a.c. power lines.
In this document, a buried pipeline (or structure) is a buried or immersed pipeline (or structure), as defined in EN 12954.
In the presence of a.c. interference, the protection criteria given in EN 12954:2001, Table 1, are not sufficient to demonstrate that the steel is being protected against corrosion.
This European Standard provides limits, measurement procedures, mitigation measures and information to deal with long term a.c. interference for a.c voltages at frequencies between 16,7 Hz and 60 Hz and the evaluation of a.c. corrosion likelihood.
This European Standard deals with the possibility of a.c. corrosion of metallic pipelines due to a.c. interferences caused by inductive, conductive or capacitive coupling with a.c. power systems and the maximum tolerable limits of these interference effects. It takes into account the fact that this is a long-term effect, which occurs during normal operating conditions of the a.c. power system.
This European Standard does not cover the safety issues associated with a.c. voltages on pipelines. These are covered in national standards and regulations (see EN 50443).

This Technical Specification is applicable to buried or immersed cathodically protected metallic structures and influenced by a.c. traction systems and/or a.c. power lines.
   In the presence of a.c. interference, the criteria given in EN 12954:2001, Table 1, are not sufficient to demonstrate that the steel is being protected against corrosion.
   This Technical Specification provides limits, measurements procedures and information to deal with long term a.c. interference and evaluating a.c. corrosion likelihood.
   Even though short term interference can cause damage to buried pipelines (e.g. arc fusion), this Technical Specification does not deal with short term interference.