EN ISO 10426-1:2006

SLOVENSKI STANDARD
01-januar-2007
1DGRPHãþD
SIST EN ISO 10426-1:2000
SIST EN ISO 10426-1:2000/A1:2004
Industrija za predelavo nafte in zemeljskega plina - Cementi in materiali za
cementiranje vrtin - 1. del: Specifikacija (ISO 10426-1:2005)
Petroleum and natural gas industries - Cements and materials for well cementing - Part
1: Specification (ISO 10426-1:2006)
Erdöl- und Erdgasindustrie - Zemente und Materialien für die Zementation von
Tieflochbohrungen - Teil 1: Anforderungen (ISO 10426-1:2006)
Industries du pétrole et du gaz naturel - Ciments et matériaux pour la cimentation des
puits -- Partie 1: Spécifications (ISO 10426-1:2006)
Ta slovenski standard je istoveten z: EN ISO 10426-1:2006
ICS:
75.180.10 Oprema za raziskovanje in Exploratory and extraction
odkopavanje 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.

EUROPEAN STANDARD
EN ISO 10426-1
NORME EUROPÉENNE
EUROPÄISCHE NORM
October 2006
ICS 91.100.10; 75.020 Supersedes EN ISO 10426-1:2000
English Version
Petroleum and natural gas industries - Cements and materials
for well cementing - Part 1: Specification (ISO 10426-1:2005)
Industries du pétrole et du gaz naturel - Ciments et Erdöl- und Erdgasindustrie - Zemente und Materialien für
matériaux pour la cimentation des puits -- Partie 1: die Zementation von Tieflochbohrungen - Teil 1:
Spécifications (ISO 10426-1:2005) Anforderungen (ISO 10426-1:2005)
This European Standard was approved by CEN on 6 October 2006.
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 Central Secretariat 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 Central Secretariat has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,
Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania,
Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: rue de Stassart, 36  B-1050 Brussels
© 2006 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 10426-1:2006: E
worldwide for CEN national Members.

Foreword
The text of ISO 10426-1:2005 has been prepared by Technical Committee ISO/TC 67
"Materials, equipment and offshore structures for petroleum and natural gas industries” of the
International Organization for Standardization (ISO) and has been taken over as EN ISO 10426-
1:2006 by Technical Committee CEN/TC 12 "Materials, equipment and offshore structures for
petroleum, petrochemical and natural gas industries", the secretariat of which is held by AFNOR.

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 April 2007, and conflicting national
standards shall be withdrawn at the latest by April 2007.

This document supersedes EN ISO 10426-1:2000.

According to the CEN/CENELEC Internal Regulations, the national standards organizations of
the following countries are bound to implement this European Standard: Austria, Belgium,
Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary,
Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland,
Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.

Endorsement notice
The text of ISO 10426-1:2005 has been approved by CEN as EN ISO 10426-1:2006 without any
modifications.
INTERNATIONAL ISO
STANDARD 10426-1
Second edition
2005-12-15
Petroleum and natural gas industries —
Cements and materials for well
cementing —
Part 1:
Specification
Industries du pétrole et du gaz naturel — Ciments et matériaux pour la
cimentation des puits —
Partie 1: Spécifications
Reference number
ISO 10426-1:2005(E)
©
ISO 2005
ISO 10426-1:2005(E)
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©  ISO 2005
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ii © ISO 2005 – All rights reserved

ISO 10426-1:2005(E)
Contents Page
Foreword. iv
Introduction . v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions. 2
4 Requirements . 3
4.1 Specification, chemical and physical requirements . 3
4.2 Sampling frequency, timing of tests and equipment. 8
5 Sampling procedure . 9
6 Fineness tests . 9
6.1 Procedure . 9
6.2 Requirements . 9
7 Preparation of slurry for free fluid, compressive strength and thickening time tests . 10
7.1 Apparatus . 10
7.2 Procedure . 11
8 Free-fluid test (free water). 11
8.1 Apparatus . 11
8.2 Calibration . 16
8.3 Procedure . 17
8.4 Calculation of percent free fluid. 17
8.5 Acceptance requirements. 18
9 Compressive strength tests . 18
9.1 Apparatus . 18
9.2 Procedure . 19
9.3 Test procedure (derived from ASTM C109). 20
9.4 Compressive strength acceptance criteria . 20
10 Thickening-time tests. 21
10.1 Apparatus . 21
10.2 Calibration . 27
10.3 Procedure . 30
10.4 Thickening time and consistency . 35
10.5 Specification acceptance requirements.35
11 Marking . 35
12 Packing . 36
13 Bentonite . 36
Annex A (informative) Calibration procedures for thermocouples, temperature-measuring
systems and controllers . 37
Bibliography . 39

ISO 10426-1:2005(E)
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.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of technical committees is to prepare International Standards. Draft International Standards
adopted by the technical committees are circulated to the member bodies for voting. Publication as an
International Standard requires approval by at least 75 % of the member bodies casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. ISO shall not be held responsible for identifying any or all such patent rights.
ISO 10426-1 was prepared by Technical Committee ISO/TC 67, Materials, equipment and offshore structures
for petroleum, petrochemical and natural gas industries, Subcommittee SC 3, Drilling and completion fluids,
and well cements.
This second edition cancels and replaces the first edition (ISO 10426-1:2000), of which has it constitutes a
minor revision. It also incorporates the Amendment ISO 10426-1:2000/Amd.1:2002.
ISO 10426 consists of the following parts, under the general title Petroleum and natural gas industries —
Cements and materials for well cementing:
⎯ Part 1: Specification
⎯ Part 2: Testing of well cement
⎯ Part 3: Testing of deepwater well cement formulations
⎯ Part 4: Preparation and testing of foamed cement slurries at atmospheric pressure
⎯ Part 5: Determination of shrinkage and expansion of well cement formulations at atmospheric pressure
A future Part 6, describing methods for determining the static gel strength of cement formulations, is under
preparation.
iv © ISO 2005 – All rights reserved

ISO 10426-1:2005(E)
Introduction
The first edition of this part of ISO 10426 was based on API Specification 10A, 22nd edition, January 1995.
This was in turn adopted by API as API Specification 10A, 23rd edition, April 2002. This second edition of this
part of ISO 10426 incorporates ISO 10426-1:2000/Amendment 1:2002 with the intent that the 24th edition of
API Specification 10A will be identical to this part of ISO 10426.
Users of this part of ISO 10426 should be aware that further or differing requirements may be needed for
individual applications. This part of ISO 10426 is not intended to inhibit a vendor from offering, or the
purchaser from accepting, alternative equipment or engineering solutions for the individual application. This
may be particularly applicable where there is innovative or developing technology. Where an alternative is
offered, the vendor should identify any variations from this part of ISO 10426 and provide details.
In this part of ISO 10426, where practical, U.S. Customary units are included in brackets for information.
INTERNATIONAL STANDARD ISO 10426-1:2005(E)

Petroleum and natural gas industries — Cements and materials
for well cementing —
Part 1:
Specification
1 Scope
This part of ISO 10426 specifies requirements and gives recommendations for eight classes of well cements,
including their chemical and physical requirements and procedures for physical testing.
This part of ISO 10426 is applicable to well cement classes A, B, C, D, E and F, 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 classes D, E and F.
This part of ISO 10426 is also applicable to well cement classes G and H, which are the products obtained by
grinding Portland cement clinker with no additives other than calcium sulfate or water.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO 3310-1, Test sieves — Technical requirements and testing — Part 1: Test sieves of metal wire cloth
ISO 13500, Petroleum and natural gas industries — Drilling fluid materials — Specifications and tests
ASTM C109/C109M, Standard Test Method for Compressive Strength of Hydraulic Cement Mortars
(Using 2-in or [50-mm] Cube Specimens)
ASTM C114, Standard Test Methods for Chemical Analysis of Hydraulic Cement
ASTM C115, Standard Test Methods for Fineness of Portland Cement by the Turbidimeter
ASTM C183, Standard Practice for Sampling and the Amount of Testing of Hydraulic Cement
ASTM C204, Standard Test Method for Fineness of Hydraulic Cement by Air Permeability Apparatus
ASTM C465, Standard Specification for Processing Additions for Use in the Manufacture of Hydraulic
Cements
ASTM E220, Standard Test Method for Calibration of Thermocouples by Comparison Techniques
ASTM E1404, Standard Specification for Laboratory Class Conical Flasks
DIN 12385, Laboratory glassware, conical flasks, wide neck
ISO 10426-1:2005(E)
EN 196-2, Methods of testing cement — Part 2: Chemical analysis of cement
EN 196-6, Methods of testing cement — Part 6: Determination of fineness
EN 196-7, Methods of testing cement — Part 7: Methods of taking and preparing samples of cement
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
additive
material added to a cement slurry to modify or enhance some desired property
NOTE Properties that are commonly modified include: setting time (by use of retarders or accelerators), fluid loss,
viscosity, etc.
3.2
Bearden unit of consistency
B
c
measure of the consistency of a cement slurry when determined on a pressurized consistometer
3.3
bulk density
mass per unit volume of a dry material containing entrained air
3.4
cement
Portland cement
ground clinker generally consisting of hydraulic calcium silicates and aluminates and usually containing one or
more forms of calcium sulfate as an interground additive
3.5
cement class
designation achieved using the ISO system of classification of well cement according to its intended use
3.6
cement grade
designation achieved using the ISO system for denoting the sulfate resistance of a particular cement
3.7
cement blend
mixture of dry cement and other dry materials
3.8
clinker
fused materials from the kiln in cement manufacturing that are interground with calcium sulfate to make
cement
3.9
compressive strength
force per unit area required to crush a set cement sample
3.10
consistometer
device used to measure the thickening time of a cement slurry under temperature and pressure
2 © ISO 2005 – All rights reserved

ISO 10426-1:2005(E)
3.11
filtrate
liquid that is forced out of a cement slurry during a fluid loss test
3.12
free fluid
coloured or colourless liquid which has separated from a cement slurry
3.13
neat cement slurry
cement slurry consisting of only cement and water
3.14
pressure vessel
vessel in a consistometer into which the slurry container is placed for the thickening time test
3.15
slurry container
slurry cup
container in a pressurized consistometer used to hold the slurry for conditioning purposes or for the thickening
time test
3.16
thickening time
time for a cement slurry to develop a selected B
c
NOTE The results of a thickening time test provide an indication of the length of time a cement slurry remains
pumpable under the test conditions.
4 Requirements
4.1 Specification, chemical and physical requirements
4.1.1 Classes and grades
Well cement shall be specified using the following Classes (A, B, C, D, E, F, G and H) and Grades (O, MSR
and HSR).
A processing additive or set-modifying agent shall not prevent a well cement from performing its intended
functions.
a) Class A
The product obtained by grinding Portland cement clinker, consisting essentially of hydraulic calcium
silicates, usually containing one or more forms of calcium sulfate as an interground additive. At the option

of the manufacturer, processing additives may be used in the manufacture of Class A cement, provided
such materials in the amounts used have been shown to meet the requirements of ASTM C465.
This product is intended for use when special properties are not required and is available only in ordinary
(O) grade (similar to ASTM C150, Type I).
b) Class B
The product obtained by grinding Portland cement clinker, consisting essentially of hydraulic calcium
silicates, usually containing one or more forms of calcium sulfate as an interground additive. At the option
of the manufacturer, processing additives may be used in the manufacture of Class B cement, provided
such materials in the amounts used have been shown to meet the requirements of ASTM C465.
ISO 10426-1:2005(E)
This product is intended for use when conditions require moderate or high sulfate-resistance and is
available in both moderate sulfate-resistant (MSR) and high sulfate-resistant (HSR) grades (similar to
ASTM C150, Type II).
c) Class C
The product obtained by grinding Portland cement clinker, consisting essentially of hydraulic calcium
silicates, usually containing one or more forms of calcium sulfate as an interground additive. At the option
of the manufacturer, processing additives may be used in the manufacture of Class C cement, provided
such materials in the amounts used have been shown to meet the requirements of ASTM C465.
This product is intended for use when conditions require high early strength and is available in ordinary
(O), moderate sulfate-resistant (MSR) and high sulfate-resistant (HSR) grades (similar to ASTM C150,
Type III).
d) Class D
The product obtained by grinding Portland cement clinker, consisting essentially of hydraulic calcium
silicates, usually containing one or more forms of calcium sulfate as an interground additive. At the option
of the manufacturer, processing additives may be used in the manufacture of Class D cement, provided
such materials in the amounts used have been shown to meet the requirements of ASTM C465. Further,
at the option of the manufacturer, suitable set-modifying agents may be interground or blended during
manufacture.
This product is intended for use under conditions of moderately high temperatures and pressures and is
available in moderate sulfate-resistant (MSR) and high sulfate-resistant (HSR) grades.
e) Class E
The product obtained by grinding Portland cement clinker, consisting essentially of hydraulic calcium
silicates, usually containing one or more forms of calcium sulfate as an interground additive. At the option
of the manufacturer, processing additives may be used in the manufacture of Class E cement, provided
such materials in the amounts used have been shown to meet the requirements of ASTM C465. Further,
at the option of the manufacturer, suitable set-modifying agents may be interground or blended during
manufacture.
This product is intended for use under conditions of high temperatures and pressures and is available in
moderate sulfate-resistant (MSR) and high sulfate-resistant (HSR) grades.
f) Class F
The product obtained by grinding Portland cement clinker, consisting essentially of hydraulic calcium
silicates, usually containing one or more forms of calcium sulfate as an interground additive. At the option
of the manufacturer, processing additives may be used in the manufacture of Class F cement, provided
such materials in the amounts used have been shown to meet the requirements of ASTM C465. Further,
at the option of the manufacturer, suitable set-modifying agents may be interground or blended during
manufacture.
This product is intended for use under conditions of extremely high temperatures and pressures and is
available in moderate sulfate-resistant (MSR) and high sulfate-resistant (HSR) grades.
4 © ISO 2005 – All rights reserved

ISO 10426-1:2005(E)
g) Class G
The product obtained by grinding Portland cement clinker, consisting essentially of hydraulic calcium
silicates, usually containing one or more forms of calcium sulfate as an interground additive. No additives
other than calcium sulfate or water, or both, shall be interground or blended with the clinker during
manufacture of Class G well cement, with the following exception. In order to comply with Directive
2003/53/EC of the European Parliament and of the Council, it is permitted until 2009-12-31 to include
chemical additives, as required, for chromium(VI) reduction, provided that such additives do not prevent
the well cement from performing its intended purpose.
This product is intended for use as a basic well cement and is available in moderate sulfate-resistant
(MSR) and high sulfate-resistant (HSR) grades.
h) Class H
The product obtained by grinding Portland cement clinker, consisting essentially of hydraulic calcium
silicates, usually containing one or more forms of calcium sulfate as an interground additive. No additives
other than calcium sulfate or water, or both, shall be interground or blended with the clinker during
manufacture of Class H well cement, with the following exception. In order to comply with Directive
2003/53/EC of the European Parliament and of the Council, it is permitted until 2009-12-31 to include
chemical additives, as required, for chromium(VI) reduction, provided that such additives do not prevent
the well cement from performing its intended purpose.
This product is intended for use as a basic well cement and is available in moderate sulfate-resistant
(MSR) and high sulfate-resistant (HSR) grades.
A well cement which has been manufactured and supplied in accordance with this part of ISO 10426 may be
mixed and placed in the field using water ratios or additives at the user’s discretion. It is not intended that
manufacturing compliance with this part of ISO 10426 be based on such field conditions.
4.1.2 Chemical requirements
Well cements shall conform to the respective chemical requirements of classes and grades referenced in
Table 1.
Chemical analyses of hydraulic cements shall be carried out as specified in ASTM C114 (or EN 196-2).
4.1.3 Physical and performance requirements
Well cement shall conform to the respective physical and performance requirements referenced in Table 2
and specified in Clauses 6, 7, 8, 9 and 10.
ISO 10426-1:2005(E)
Table 1 — Chemical requirements
Cement class
A B C D, E, F G H
Ordinary grade (O)
Magnesium oxide (MgO), maximum, % 6,0 NA 6,0 NA NA NA
a
Sulfur trioxide (SO ), maximum, % 3,5 NA 4,5 NA NA NA
Loss on ignition, maximum, % 3,0 NA 3,0 NA NA NA
Insoluble residue, maximum, % 0,75 NA 0,75 NA NA NA
Tricalcium aluminate (C A), maximum, % NR NA 15 NA NA NA
Moderate sulfate-resistant grade (MSR)
Magnesium oxide (MgO), maximum, % NA 6,0 6,0 6,0 6,0 6,0
Sulfur trioxide (SO), maximum, % NA 3,0 3,5 3,0 3,0 3,0
Loss on ignition, maximum, % NA 3,0 3,0 3,0 3,0 3,0
Insoluble residue, maximum, % NA 0,75 0,75 0,75 0,75 0,75
b b
Tricalcium silicate (CS) maximum, % NA NR NR NR 58 58
b b
minimum, % NA NR NR NR 48 48
Tricalcium aluminate (CA), maximum % NA 8 8 8 8 8
Total alkali content, expressed as sodium oxide
c c
NA NR NR NR 0,75 0,75
(Na O) equivalent, maximum, %
High sulfate-resistant grade (HSR)
Magnesium oxide (MgO), maximum, % NA 6,0 6,0 6,0 6,0 6,0
Sulfur trioxide (SO), maximum, % NA 3,0 3,5 3,0 3,0 3,0
Loss on ignition, maximum, % NA 3,0 3,0 3,0 3,0 3,0
Insoluble residue, maximum, % NA 0,75 0,75 0,75 0,75 0,75
b b
Tricalcium silicate (CS) maximum, % NA NR NR NR 65 65
b b
minimum, % NA NR NR NR 48 48
b b b b b
Tricalcium aluminate (C A), maximum, % NA 3 3 3 3 3
Tetracalcium aluminoferrite (C AF) plus twice the
4 b b b b b
NA 24 24 24 24 24
tricalcium aluminate (C A), maximum, %
Total alkali content expressed as sodium oxide (Na O)
2 c c
NA NR NR NR 0,75 0,75
equivalent, maximum, %
NR = No Requirement; NA = Not Applicable
a
When the tricalcium aluminate content (expressed as C A) of the cement is 8 % or less, the maximum SO content shall be 3 %.
3 3
b
The expressing of chemical limitations by means of calculated assumed compounds does not necessarily mean that the oxides are
actually or entirely present as such compounds. When the ratio of the percentages of Al O to Fe O is 0,64 or less, the C A content is
2 3 2 3 3
zero. When the Al O to Fe O ratio is greater than 0,64, the compounds shall be calculated as follows:
2 3 2 3
C A = (2,65 × % Al O ) – (1,69 × % Fe O )
3 2 3 2 3
C AF = 3,04 × % Fe O
4 2 3
C S = (4,07 × % CaO) – (7,60 × % SiO ) – (6,72 × % Al O ) – (1,43 × % Fe O ) – (2,85 × % SO )
3 2 2 3 2 3 3
When the ratio of Al O to Fe O is less than 0,64, the C S shall be calculated as follows:
2 3 2 3 3
C S = (4,07 × % CaO) – (7,60 × % SiO ) – (4,48 × % Al O ) – (2,86 × % Fe O ) – (2,85 × % SO )
3 2 2 3 2 3 3
c
The sodium oxide equivalent (expressed as Na O equivalent) shall be calculated by the formula:
Na O equivalent = (0,658 × % K O) + (% Na O).
2 2 2
6 © ISO 2005 – All rights reserved

ISO 10426-1:2005(E)
Table 2 — Summary of physical and performance requirements
Well cement class A B C D E F G H
Mix water, % mass fraction of cement (Table 5)
46 46 56 38 38 38 44 38
Fineness tests (alternative methods) (Clause 6)

Turbidimeter (specified surface, minimum 150 160 220 NR NR NR NR NR
m /kg)
Air permeability (specified surface, minimum 280 280 400 NR NR NR NR NR
m /kg)
Free fluid content, maximum % (Clause 8) NR NR NR NR NR NR 5,9 5,9
Compressive Schedule Final Final Minimum compressive strength
strength test number, curing curing
MPa (psi)
temp. pressure
(8-h curing Table 6
time) °C (°F) MPa (psi)
(Clause 9)
NA 38 (100) atm. 1,7 1,4 2,1 NR NR NR 2,1 2,1
(250) (200) (300) (300) (300)
NA 60 (140) atm. NR NR NR NR NR NR 10,3 10,3
(1 500) (1 500)
6S 110 (230) 20,7 NR NR NR 3,4 NR NR NR NR
(3 000) (500)
8S 143 (290) 20,7 NR NR NR NR 3,4 NR NR NR
(3 000) (500)
9S 160 (320) 20,7 NR NR NR NR NR 3,4 NR NR
(3 000) (500)
Compressive Schedule Final Final Minimum compressive strength
strength test number, curing curing
MPa (psi)
temp. pressure
(24-h curing Table 6
time) °C (°F) MPa (psi)
(Clause 9)
NA 38 (100) Atm. 12,4 10,3 13,8 NR NR NR NR NR
(1 800) (1 500) (2 000)
4S 77 (170) 20,7 NR NR NR 6,9 6,9 NR NR NR
(3 000) (1 000) (1 000)
6S 110 (230) 20,7 NR NR NR 13,8 NR 6,9 NR NR
(3 000) (2 000) (1 000)
8S 143 (290) 20,7 NR NR NR NR 13,8 NR NR NR
(3 000) (2 000)
9S 160 (320) 20,7 NR NR NR NR NR 6,9 NR NR
(3 000) (1 000)
ISO 10426-1:2005(E)
Table 2 (continued)
Well cement Class A B C D E F G H
Pressure Specifi- Maximum Thickening time (min./max.)
temperature cation test consistency
min
thickening Schedule
(15 min
time test number
to 30 min
(Clause 10) Tables 9 stirring
a
through 13 period) B
c
4 30 — 90 90 90 90 NR NR NR NR
min. min. min. min.
5 30 — NR NR NR NR NR NR 90 90
min. min.
5 30 — NR NR NR NR NR NR 120 120
max. max.
6 30 — NR NR NR 100 100 100 NR NR
min. min. min.
8 30 — NR NR NR NR 154 NR NR NR
min.
9 30 — NR NR NR NR NR 190 NR NR
min.
a
Bearden units of consistency (B ) obtained on a pressurized consistometer as defined in Clause 10 and calibrated as per the same
c
clause.
NR = No Requirement.
4.2 Sampling frequency, timing of tests and equipment
4.2.1 Sampling frequency
For well cement Classes C, D, E, F, G and H, a sample for testing shall be taken by either method (1) over a
24-h interval or method (2) on a 1 000 ton (maximum) production run.
For well cement Classes A and B, a sample for testing shall be taken by either method (1) over a 14-day
interval or method (2) on a 25 000 ton (maximum) production run.
These samples shall represent the product as produced. At the choice of the manufacturer, either method (1)
or method (2) may be used.
4.2.2 Time from sampling to testing
Each sample shall be tested for conformance to this part of ISO 10426. All tests shall be completed within
seven working days after sampling.
4.2.3 Specified equipment
Equipment used for testing well cements shall comply with Table 3. Dimensions shown in Figures 5, 6, 10
and 11 are for cement specification test equipment manufacturing purposes. Dimensional recertification shall
not be required.
8 © ISO 2005 – All rights reserved

ISO 10426-1:2005(E)
Table 3 — Specification test equipment for well-cement manufacturers
Test or preparation Well cement Clause Required equipment
classes reference
Sampling All Clause 5 Apparatus specified in ASTM C 183 (or EN 196-7).
Fineness A, B, C Clause 6 Turbidimeter and auxiliary equipment as specified in ASTM C 115 or
air permeability apparatus and auxiliary equipment as specified in
ASTM C 204 (or EN 196-6)
Slurry preparation All Clause 7 Apparatus specified in 7.1
Free fluid G, H Clause 8 Apparatus specified in 8.1
Atmospheric pressure A, B, C, G, H Clause 9 Apparatus specified in 9.1, except pressure vessel of 9.1.3.2
compressive strength
Pressure cured D, E, F Clause 9 Apparatus specified in 9.1
compressive strength
Thickening time All Clause 10 Pressurized consistometer specified in 10.1
4.2.4 Calibration
Equipment calibrated to the requirements of this part of ISO 10426 is considered to be accurate if calibration
is within the specified limits.
5 Sampling procedure
One or more of the procedures outlined in ASTM C183 (or EN 196-7) shall be used to secure a sample of well
cement for specification testing purposes.
6 Fineness tests
6.1 Procedure
Tests for fineness of well cement shall be carried out in accordance with either the procedure in ASTM C115
for the turbidimeter test or the procedure in ASTM C204 (or EN 196-6) by air permeability apparatus for the air
permeability test.
6.2 Requirements
Acceptance requirements for the fineness test are a minimum specific surface area (expressed in square
metres per kilogram) and are as given in Table 2. Cement Classes D, E, F, G and H have no fineness
requirement.
Either of the two fineness test methods (turbidimeter or air permeability test) shall be used, at the discretion of
the manufacturer, to determine the fineness.
ISO 10426-1:2005(E)
7 Preparation of slurry for free fluid, compressive strength and thickening time
tests
7.1 Apparatus
7.1.1 Scales
The indicated load on scales shall be accurate within 0,1 % of the indicated load. Annual calibration is
required.
7.1.2 Masses
Masses shall be accurate within the tolerance shown in Table 4. On beam-type scales where the masses are
on the beam, the indicated masses shall conform to the requirements given in 7.1.1.
Table 4 — Permissible variation in weights
Mass Permissible variation
g g
1 000 ± 0,5
500 ± 0,35
300 ± 0,30
200 ± 0,20
100 ± 0,15
50 ± 0,10
7.1.3 Sieves
A No. 20 wire cloth sieve (openings 850 µm), meeting the requirements given in ISO 3310-1, shall be used for
sieving cement prior to slurry preparation.
7.1.4 Mixing devices
The mixing device for preparation of well cement slurries shall be a one litre (or one quart) size, bottom-drive,
blade type mixer.
Examples of mixing devices in common use are shown in Figure 1. The mixing blade and mixing container
shall be constructed of durable corrosion-resistant material. The mixing assembly shall be constructed in such
a manner that the blade can be removed for weighing and changing. The mixing blade shall be weighed prior
to use and replaced with an unused blade when a 10 % mass loss has occurred. If water leakage occurs
around the bearings, the entire blade and container assembly should be replaced.

Figure 1 — Examples of typical cement-mixing devices
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ISO 10426-1:2005(E)
7.2 Procedure
7.2.1 Sieving
Prior to mixing, the cement shall be sieved as described in ASTM C183.
7.2.2 Temperature of water and cement
The temperature of the mix water in the container within 60 s prior to mixing shall be 23 °C ± 1 °C
(73 °F ± 2 °F) and that of the cement within 60 s prior to mixing shall be 23 °C ± 1 °C (73 °F ± 2 °F).
7.2.3 Mix water
Distilled or deionized water shall be used for testing. The mix water shall be weighed directly into a clean, dry
mixing container. No water shall be added to compensate for evaporation, wetting, etc.
7.2.4 Mixing quantities
Slurry component quantities shown in Table 5 shall be used for testing. The use of the quantities of
components shown in Table 5 will result in mix-water percentages (based on the mass of dry cement)
consistent with water percentages shown in Table 2.
Table 5 — Slurry requirements
Components Classes A and B Class C Classes D, E, F, H Class G
g g g g
Mix water 355 ± 0,5 383 ± 0,5 327 ± 0,5 349 ± 0,5
Cement
772 ± 0,5 684 ± 0,5 860 ± 0,5 792 ± 0,5
7.2.5 Mixing cement and water
The mixing container with the required mass of mix water, as specified in Table 5, shall be placed on the
mixer base, the motor turned on and maintained at 4 000 r/min ± 200 r/min (66,7 r/s ± 3,3 r/s) while the
cement sample is added at a uniform rate in not more than 15 s. After all of the cement has been added to the
mix water, the cover shall be placed on the mixing container and mixing shall be continued at
12 000 r/min ± 500 r/min(200 r/s ± 8,3 r/s) for 35 s ±1 s.
8 Free-fluid test (free water)
8.1 Apparatus
8.1.1 Consistometer
The atmospheric pressure consistometer or the pressurized consistometer described in 10.1 (run at
atmospheric pressure) shall be used for stirring and conditioning the cement slurry for determination of free-
fluid content. The atmospheric consistometer consists of a rotating cylindrical slurry container, equipped with
an essentially stationary paddle assembly, in a temperature controlled liquid bath. It shall be capable of
maintaining the temperature of the bath at 27 °C ± 1,7 °C (80 °F ± 3 °F) and of rotating the slurry container at
a speed of 150 r/min ±15 r/min (2,5 r/s ± 0,25 r/s) during the stirring and conditioning period for the slurry. The
paddle and all parts of the slurry container exposed to the slurry shall be constructed of corrosion-resistant
materials. See Figures 2, 3, 4 and 5.
NOTE The paddle may be used to drive a “potentiometer” (see Figures 2 and 3) to measure slurry viscosity.
ISO 10426-1:2005(E)
Key
1 cap lock nut
2 centre lock reverse jam nut
3 dial
4 pointer
5 dial and base assembly
6 spring
7 collar
8 bearing
9 retaining ring
10 lid
11 roll pin
12 shaft
Figure 2 — Typical potentiometer mechanism for atmospheric pressure consistometer
12 © ISO 2005 – All rights reserved

ISO 10426-1:2005(E)
Key
1 lid (see Figure 2)
2 fill indicating groove
3 slurry container (see Figure 4)
4 paddle (see Figure 5)
Figure 3 — Container assembly for typical atmospheric pressure consistometer
ISO 10426-1:2005(E)
Dimensions in millimetres (inches)

Key
1 2 slots 180° apart
2 fill-level indicating groove
3 pivot bearing
Figure 4 — Container for typical atmospheric pressure consistometer
14 © ISO 2005 – All rights reserved

ISO 10426-1:2005(E)
Dimensions in millimetres (inches)

NOTE 1 Paddle material: type 302 stainless steel 1,0 mm × 7,9 mm (0,04 in × 0,313 in) cold-rolled strip.
NOTE 2 Shaft material: type 416 steel 6,4 mm × 211,1 mm (0,25 in × 8,313 in) annealed and ground.
Figure 5 — Paddle for typical atmospheric pressure consistometer
ISO 10426-1:2005(E)
8.1.2 Scales
Scales shall meet the requirements of 7.1.1.
8.1.3 Test flask
A 500 ml conical flask in accordance with ASTM E1404, Type I, Class 2 or DIN 12385 shall be used. See
Figure 6.
Dimensions in millimetres
Key
1 ASTM conical flask (Type 1, Class 2), capacity 500 ml
a
Wall thickness.
b
OD (at widest point).
Figure 6 — Conical flask for measurement of free fluid
8.2 Calibration
8.2.1 Temperature-measuring system
The temperature of the bath shall be measured by thermometer (glass or digital) and/or thermocouple with
digital indicator which are accurate to ± 1,7 °C (± 3 °F). Thermocouples shall be ASTM E220 classification
“special” Type J. Thermocouples with digital indicators and thermometers shall be checked for accuracy
against a certified thermometer, traceable to the reference of the national body responsible for standards of
temperature measurement, no less frequently than monthly. Thermocouples with digital indicators and
thermometers found outside the acceptable ± 1,7 °C (± 3 °F) range shall be corrected or replaced. See
Annex A.
8.2.2 Slurry container rotational speed
The rotational speed shall be 150 r/min ± 15 r/min (2,5 r/s ± 0,25 r/s). The rotational speed of the slurry
container shall be checked no less frequently than quarterly, and corrected if found to be inaccurate.
8.2.3 Timer
The timer shall be accurate to within ± 30 s per hour. It shall be checked for accuracy no less frequently than
semi-annually, and corrected or replaced if found to be inaccurate.
16 © ISO 2005 – All rights reserved

ISO 10426-1:2005(E)
8.3 Procedure
8.3.1 Prepare the slurry according to the procedure in Clause 7.
8.3.2 Fill a clean and dry consistometer slurry container to the proper level.
8.3.3 Assemble the slurry container and associated parts, place them in the consistometer and start the
motor according to the operating instructions of the manufacturer. The interval between completion of mixing
and starting of the consistometer shall not exceed 1 min.
8.3.4 Stir the slurry in the consistometer for a period of 20 min ± 30 s. Maintain the bath temperature at
27 °C ± 1,7 °C (80 °F ± 3 °F) throughout the stirring period.
8.3.5 Transfer 790 g ± 5 g of Class H slurry or 760 g ± 5 g of Class G slurry directly into the clean, dry
500 ml conical flask within 1 min. Record the actual mass transferred. S
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