prEN ISO 10426-1

• Abstract:

  ISO 10426-1:2009 specifies requirements and gives recommendations for six classes of well cements, including their chemical and physical requirements and procedures for physical testing.; ISO 10426-1:2009 is applicable to well cement classes A, B, C and D, which are the products obtained by grinding Portland cement clinker and, if needed, calcium sulfate as an interground additive. Processing additives can be used in the manufacture of cement of these classes. Suitable set-modifying agents can be interground or blended during manufacture of class D cement.; ISO 10426-1:2009 is also applicable to well cement classes G and H, which are the products obtained by grinding clinker with no additives other than one or more forms of calcium sulfate, water or chemical additives as required for chromium (VI) reduction.

• Status: Not Published
• Publication Date: 18-Oct-2027
• ICS: 91.100.10 - Cement. Gypsum. Lime. Mortar
• Technical Committee: CEN/TC 12 - Materials, equipment and offshore structures for petroleum and natural gas industries
• Drafting Committee: CEN/TC 12 - Materials, equipment and offshore structures for petroleum and natural gas industries
• Current Stage: 4060 - Closure of enquiry - Enquiry
• Start Date: 21-Jul-2026
• Completion Date: 21-Jul-2026
• Ref Project: oSIST prEN ISO 10426-1:2026 - Oil and gas industries including lower carbon energy - Cements and materials for well cementing - Part 1: Specification (ISO/DIS 10426-1:2026)

• Revises: EN ISO 10426-1:2009/AC:2010 - Petroleum and natural gas industries - Cements and materials for well cementing - Part 1: Specification - Technical Corrigendum 1 (ISO 10426-1:2009/Cor 1:2010)
• Effective Date: 25-Feb-2026
• Revises: EN ISO 10426-1:2009/AC:2018 - Petroleum and natural gas industries - Cements and materials for well cementing - Part 1: Specification - Technical Corrigendum 2 (ISO 10426-1:2009/Cor 2:2012)
• Effective Date: 25-Feb-2026
• Revises: EN ISO 10426-1:2009 - Petroleum and natural gas industries - Cements and materials for well cementing - Part 1: Specification (ISO 10426-1:2009)
• Effective Date: 25-Feb-2026

prEN ISO 10426-1 is a CEN draft standard in the ISO/CEN process for cements and materials for well cementing in the oil and gas industries including lower carbon energy. It specifies requirements and recommendations for eight classes of well cements, covering chemical and physical requirements, physical testing, and a supplement to API Spec 10A for product and environmental declaration data.

What does prEN ISO 10426-1 specify?

prEN ISO 10426-1 specifies the requirements for well cements used in well cementing and organizes them around the cement classes used in practice. It also sets out how the document supplements API Spec 10A, 25th edition (2019), which is the base specification it builds on.

The scope covers classes A, B, C, D, G, H, K and L. In practical terms, that means a supplier needs to identify the cement class being offered and follow the production route and additive limits tied to that class.

Classes A, B, C and D are Portland-cement-based products. Classes G and H are clinker-based products with only calcium sulfate, water or chemical additives used for chromium (VI) reduction. Classes K and L are composite well cements made with specified composite constituents, either by intergrinding or by later blending.

The document is organized into:

• Clause 1 Scope
• Clause 2 Normative references
• Clause 3 Terms and definitions
• Clause 4 Supplements to API Spec 10A, with:
  • 4.1 General requirements
  • 4.2 Determining The Global Warming Potential (GWP) of Well Cements

What are the key requirements of prEN ISO 10426-1?

prEN ISO 10426-1 uses API Spec 10A, 25th edition (2019), as the baseline and adds specific supplements where this document says otherwise. For users, that means conformity work starts with API Spec 10A and then checks the extra conditions in clause 4.

1) The API Spec 10A requirements apply first

Clause 4.1 says the requirements in API Spec 10A, 25th edition (2019), apply, except for the exceptions in 4.2. In practice, manufacturers and labs need to treat API Spec 10A as the main compliance reference and then add the extra environmental reporting requirements.

2) Product-specific EPDs are required on request

Clause 4.2 requires well cement manufacturers to maintain and provide, on request, a product-specific Type III Environmental Product Declaration (EPD). For a buyer or auditor, that means the product must be backed by a declaration that can be checked and shared.

3) The EPD must follow recognized environmental rules

Clause 4.2 says the EPD shall conform to ISO 14025, with more specific requirements set by ISO 21930 or EN 15804 for construction materials. In practice, this gives the declaration a defined format and method, so environmental claims are not free-form statements.

4) The climate data must come from cradle-to-gate LCA

Clause 4.2 requires the EPD to be based on a cradle-to-gate (A1-A3) Life Cycle Assessment (LCA) conforming to ISO 14040 and ISO 14044. That means the environmental calculation covers production up to the factory gate, which is the point most users need for product comparison and procurement.

5) Independent verification is required

Clause 4.2 says the EPD shall be independently verified and published by an established Program Operator. In practice, the declaration is not just an internal company document - it must pass external review and be issued through a recognized program.

6) The Product Category Rules must be available

Clause 4.2 requires the PCR used for cement production to be made available upon request. For users, that matters because it shows the rules behind the calculation and lets them check whether comparable products were assessed on the same basis.

7) The scope of the cement classes matters for formulation

Clause 1 separates Portland-cement-based classes, clinker-based classes with chromium (VI) reduction additives, and composite well cements. For manufacturers, that affects raw material selection, allowable additives, and how the product is classified on a certificate or data sheet.

What terms does prEN ISO 10426-1 define?

prEN ISO 10426-1 uses terms and definitions from API Spec 10A, 25th edition (2019), and adds the following key concepts in clause 4.2.

• Well cements - cements intended for well cementing, where the cement must support the well structure and meet the class-specific requirements in the document.
• Type III Environmental Product Declaration (EPD) - a standardized environmental declaration for a product, used here to report well cement environmental information in a verifiable format.
• Life Cycle Assessment (LCA) - the method used to calculate environmental impacts from raw-material supply through production to the factory gate.
• Product Category Rules (PCR) - the detailed rules that tell a product group how its environmental declaration is to be calculated.
• Global Warming Potential (GWP) - the climate-impact measure used in clause 4.2 for well cements.
• Program Operator - the body that publishes the verified EPD under the chosen EPD program.

Who uses prEN ISO 10426-1?

prEN ISO 10426-1 is used by well cement manufacturers, drilling and completion fluid specialists, test laboratories, quality managers, sustainability teams, buyers, and project specifiers. It helps them choose the correct cement class, test it, document it, and support environmental reporting.

In oil and gas work, it is relevant where well cement is formulated, manufactured, tested, purchased, or specified. It is also relevant where product-specific EPDs are requested as part of procurement or environmental review.

What changed in prEN ISO 10426-1 from the previous edition?

prEN ISO 10426-1 is the fourth edition. It cancels and replaces ISO 10426-1:2009 and Technical Corrigendum 1 (2010), and the foreword says the text has been technically revised.

The foreword states one main change: Determining The Global Warming Potential (GWP) of Well Cements. It also says the edition was updated to reference API Spec 10A, 25th edition (2019), together with Addendum 1 and Addendum 2.

Which standards are used with prEN ISO 10426-1?

prEN ISO 10426-1 names these standards and documents as part of its framework:

• API Spec 10A, 25th edition (2019) - the base cement specification that this document supplements.
• ISO 14025 - the framework for Type III environmental declarations.
• ISO 21930 - the core rules for environmental product declarations of construction products and services.
• EN 15804 - the European core rules for construction product EPDs.
• ISO 14040 - the principles and framework for LCA.
• ISO 14044 - the requirements and guidelines for LCA.

What does the prEN ISO 10426-1 document contain?

prEN ISO 10426-1 contains a short technical specification rather than a long method handbook. The text includes the scope, the reference framework, the terms and definitions clause, and a clause that supplements API Spec 10A.

Clause 4.2 is the most distinctive part because it links well cement supply to product-specific EPDs, verified environmental declarations, cradle-to-gate LCA, and PCR. The foreword also explains the relationship to the previous edition and to API Spec 10A.

SLOVENSKI STANDARD
01-julij-2026
Naftna in plinska industrija, vključno z nizkoogljično energijo - Cementi in materiali
za cementiranje vrtin - 1. del: Specifikacija (ISO/DIS 10426-1:2026)
Oil and gas industries including lower carbon energy - Cements and materials for well
cementing - Part 1: Specification (ISO/DIS 10426-1:2026)
Öl- und Gasindustrie einschließlich kohlenstoffarmer Energieträger - Zemente und
Materialien für die Zementation von Tiefbohrungen - Teil 1: Anforderungen (ISO/DIS
10426-1:2026)
Titre manque - Partie 1: Titre manque
Ta slovenski standard je istoveten z: prEN ISO 10426-1
ICS:
75.180.10 Oprema za raziskovanje, Exploratory, drilling and
vrtanje in odkopavanje extraction equipment
91.100.10 Cement. Mavec. Apno. Malta Cement. Gypsum. Lime.
Mortar
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
International
Standard
ISO/DIS 10426-1
ISO/TC 67/SC 3
Oil and gas industries including
Secretariat: UNI
lower carbon energy — Cements
Voting begins on:
and materials for well cementing —
2026-04-28
Part 1:
Voting terminates on:
2026-07-21
Specification
ICS: 75.020; 91.100.10
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
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Reference number
ISO/DIS 10426-1:2026(en)
DRAFT
ISO/DIS 10426-1:2026(en)
International
Standard
ISO/DIS 10426-1
ISO/TC 67/SC 3
Oil and gas industries including
Secretariat: UNI
lower carbon energy — Cements
Voting begins on:
and materials for well cementing —
Part 1:
Voting terminates on:
Specification
ICS: 75.020; 91.100.10
THIS DOCUMENT IS A DRAFT CIRCULATED
FOR COMMENTS AND APPROVAL. IT
IS THEREFORE SUBJECT TO CHANGE
AND MAY NOT BE REFERRED TO AS AN
INTERNATIONAL STANDARD UNTIL
PUBLISHED AS SUCH.
This document is circulated as received from the committee secretariat.
IN ADDITION TO THEIR EVALUATION AS
BEING ACCEPTABLE FOR INDUSTRIAL,
© ISO 2026
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
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Published in Switzerland Reference number
ISO/DIS 10426-1:2026(en)
ii
ISO/DIS 10426-1:2026(en)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 2
4 Supplements to API Spec 10A, 25th edition (2019) . 2
4.1 General requirements .2
4.2 Determining The Global Warming Potential (GWP) of Well Cements .2

iii
ISO/DIS 10426-1:2026(en)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee
has been established has the right to be represented on that committee. International organizations,
governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely
with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives,
...