EN 15112:2022
(Main)External cathodic protection of well casings
External cathodic protection of well casings
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.
Äußerer kathodischer Korrosionsschutz von Bohrlochverrohrungen
Dieses Dokument enthält Informationen über Verfahren, die geeignet sind, die Wahrscheinlichkeit von Leckagen aufgrund von Außenkorrosion von Bohrlochverrohrungen zu beurteilen und die Notwendigkeit eines kathodischen Korrosionsschutzes zu bewerten, sowie über Verfahren zur Bereitstellung eines kathodischen Korrosionsschutzes für den äußeren Teil dieser Bohrlöcher, der das Erdreich berührt. Es definiert auch Anforderungen an die Überwachung der Wirksamkeit von kathodischen Korrosionsschutzsystemen (CP system, en: cathodic protection system).
Der Anwendungsbereich umfasst sowohl Onshore- als auch Offshore-Bohrlöcher. Bei Offshore-Bohrlöchern, wo der Schutz durch Anoden an der Bohrlochkopfanlage erfolgt, ist es allerdings unter Umständen nicht praktikabel, einen vollständigen Schutz der Bohrlochverrohrungen zu realisieren.
Dieses Dokument ist anzuwenden für jede Gas-, Öl- oder Wasserbohrung mit metallischer Verrohrung, unabhängig davon, ob sie einzementiert ist oder nicht.
Unter besonderen Bedingungen jedoch (flachgründige Verrohrungen: z. B. 50 m und homogenes Erdreich) kann EN 12954 angewendet werden, um kathodischen Korrosionsschutz zu erreichen und dessen Wirksamkeit zu beurteilen.
Es gelten die allgemeinen Anforderungen in EN 12954; in diesem Dokument werden zusätzliche, spezifische Anforderungen für den kathodischen Korrosionsschutz von Bohrlochverrohrungen beschrieben.
Dieses Dokument ist anzuwenden für Förder- und Injektionsbohrlöcher. Spätere Verweisungen in diesem Dokument auf die Förderung gelten auch für die Injektion.
Protection cathodique externe des cuvelages de puits
Le présent document fournit des informations relatives aux méthodes appropriées d'évaluation du risque de fuite due à la corrosion externe des cuvelages de puits et d'évaluation du besoin en courant de protection cathodique ; il intègre également des méthodes permettant d'appliquer une protection cathodique à la partie extérieure de ces puits qui est en contact avec le sol. Il définit également les exigences relatives à la surveillance des performances des systèmes de protection cathodique.
Les puits à terre et en mer relèvent du domaine d'application. Cependant, lorsque la protection des puits en mer est assurée par des anodes placées sur la structure de tête de puits, c'est un fait reconnu que l'obtention d'une protection totale des cuvelages de puits peut s'avérer souvent difficile pour des raisons pratiques.
Le présent document s'applique à tous les puits de gaz, de pétrole ou d'eau à cuvelage métallique, cimenté ou non.
Néanmoins dans certaines conditions particulières (cuvelages de faible profondeur [par exemple 50 m] et sols homogènes), l'EN 12954 peut être utilisée pour réaliser la protection cathodique et évaluer son efficacité.
Les exigences générales énoncées dans l'EN 12954 s'appliquent ; le présent document décrit en détail les exigences spécifiques supplémentaires qui concernent la protection cathodique des cuvelages de puits.
Le présent document s'applique aux puits de production et aux puits d'injection. Les références relatives à la production citées plus loin dans le document s'appliquent également à l'injection.
Zunanja katodna zaščita globinskih zaščitnih cevi
Ta dokument določa metode za vrednotenje tveganj za zunanjo korozijo globinskih zaščitnih cevi ter sredstva in naprave za katodno zaščito, ki jih je treba uvesti za preprečevanje korozije zunanjega dela globinskih zaščitnih cevi, ki so v stiku z zemljo.
Ta dokument se uporablja za vse globinske zaščitne cevi za plin, olje ali vodo s kovinskim ohišjem, ki so cementirane ali necementirane.
V posebnih razmerah (plitve zaščitne cevi: npr. 50 m in homogena tla) se lahko za vzpostavitev katodne zaščite in ocenjevanje njene učinkovitosti uporablja standard EN 12954.
General Information
Relations
Standards Content (Sample)
SLOVENSKI STANDARD
01-julij-2022
Nadomešča:
SIST EN 15112:2006
Zunanja katodna zaščita globinskih zaščitnih cevi
External cathodic protection of well casings
Äußerer kathodischer Korrosionsschutz von Bohrlochverrohrungen
Protection cathodique externe des cuvelages de puits
Ta slovenski standard je istoveten z: EN 15112:2022
ICS:
25.220.40 Kovinske prevleke Metallic coatings
77.060 Korozija kovin Corrosion of metals
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EN 15112
EUROPEAN STANDARD
NORME EUROPÉENNE
May 2022
EUROPÄISCHE NORM
ICS 23.040.99; 77.060 Supersedes EN 15112:2006
English Version
External cathodic protection of well casings
Protection cathodique externe des cuvelages de puits Äußerer kathodischer Korrosionsschutz von
Bohrlochverrohrungen
This European Standard was approved by CEN on 13 March 2022.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2022 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 15112:2022 E
worldwide for CEN national Members.
Contents Page
European foreword . 4
Introduction . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 6
4 Cathodic protection personnel competence . 9
5 Description and assessment of corrosion risks .10
5.1 General .10
5.2 Description of corrosion risks .10
5.3 Corrosion risk assessment .11
5.3.1 Data collection during initial survey .11
5.3.2 Data collection during drilling .11
5.3.3 Data collection in service .11
5.3.4 Data collection during workover.12
6 Prerequisites for application of cathodic protection .12
6.1 General .12
6.2 Electrical continuity .12
6.3 Electrical isolation .13
6.3.1 General .13
6.3.2 Particular situations .13
6.4 Cathodic protection equipment .14
6.5 Groundbeds .14
6.6 Safety requirements .14
7 Design of the cathodic protection .15
7.1 General .15
7.2 Voltage drop profile method .15
7.3 Polarization curve method .15
7.4 Simulation of the cathodic protection for a well .16
7.5 Design based on historical data .16
8 Measurement of the well-casing-to-soil potential at the wellhead .16
8.1 General .16
8.2 Measuring points .16
8.3 Method used for potential measurement - Interpretation .17
8.4 CP System testing, commissioning and documentation .17
9 Additional cathodic protection equipment .18
10 CP System Monitoring, inspection and maintenance .18
Annex A (informative) Voltage drop profile .19
A.1 General .19
A.2 Principle .20
A.3 Method .20
A.4 Analysis of the curves . 21
A.5 Practical considerations . 22
Annex B (informative) Polarization curve method applied to a well . 23
B.1 General . 23
B.2 Practical considerations . 24
Annex C (informative) Calculation of the potential shift at the bottom of the well casing and
the well casing to soil resistance . 25
C.1 Purpose . 25
C.2 Principle . 25
C.3 Definition of terms and coefficients used in the equations . 26
C.3.1 Symbols and definitions . 26
C.3.2 Characteristics of a segment k . 28
C.3.3 Coefficients used in the attenuation equations . 28
C.4 Calculation - General attenuation equations . 29
C.4.1 General attenuation equations . 29
C.4.2 Method for solving the equations system . 29
C.4.3 Calculation procedure. 30
C.5 Calculation procedure example . 31
Bibliography . 34
European foreword
This document (EN 15112:2022) has been prepared by Technical Committee CEN/TC 219 “Cathodic
protection”, the secretariat of which is held by BSI.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by November 2022, and conflicting national standards shall
be withdrawn at the latest by November 2022.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN 15112:2006.
In comparison with the previous edition, the following technical modifications have been made:
— Requirements for CP personnel competences have been included.
— Additional requirements for insulation between the casing and other pipelines or well casings.
— In Annex A, the method to determine the CP current need has been simplified.
— Annex C (Calculation of the potential shift at the bottom of the well casing and the well casing to soil
resistance) has been revised.
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia,
Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland,
Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of North
Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United
Kingdom.
Introduction
Gas, oil and water well casings are usually cemented for the purpose of anchoring the pipes in the
borehole and isolating the various geological layers from each other. This is necessary to avoid liquid
exchanges between these.
Steels in contact with the cement are generally passivated, and thus, protected from external corrosion,
except if the cement contains chloride ions. However, it is not always possible to obtain a continuous
cementation on all the external steel surfaces. These bare residual surfaces can be in contact with more
or less aggressive layers. Furthermore, these surfaces can constitute electrochemical cells with the
cemented metallic parts. The anodic areas, which are the poorly cemented parts, correspond to corrosion
areas.
In general, external corrosion effects are rare, particularly on recent wells, since most of them are well
cemented. However, cementation failures sometimes occur during the execution of borehole cementation
programmes, and studies have shown that, corrosion phenomena being progressive, the mean time for
the appearance of leaks is dependent on different factors such as geological formation, thickness of the
layers and of the steel casing.
Experience has also shown that the situation can be significantly improved by applying external cathodic
protection to the well casings.
Environmental aspects with regard to gas, oil or water wells should be considered when deciding on
whether or not to apply cathodic protection.
1 Scope
This document provides information on methods suitable for assessing the likelihood of leakage due to
external corr
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