EN ISO 10426-1:2000

SLOVENSKI STANDARD
01-december-2000
Petroleum and natural gas industries - Cements and materials for well cementing -
Part 1: Specification (ISO 10426-1:2000)
Petroleum and natural gas industries - Cements and materials for well cementing - Part
1: Specification (ISO 10426-1:2000)
Erdöl- und Erdgasindustrie - Zemente und Materialien für die Zementation von
Tiefbohrungen - Teil 1: Anforderungen (ISO 10426-1:2000)
Industries du pétrole et du gaz naturel - Ciments et matériaux de cimentation des puits -
Partie 1: Spécifications (ISO 10426-1:2000)
Ta slovenski standard je istoveten z: EN ISO 10426-1:2000
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
March 2000
ICS 75.020; 91.100
English version
Petroleum and natural gas industries - Cements and materials
for well cementing - Part 1: Specification (ISO 10426-1:2000)
Industries du pétrole et du gaz naturel - Ciments et Erdöl- und Erdgasindustrie - Zemente und Materialien für
matériaux de cimentation des puits - Partie 1: die Zementation von Tiefbohrungen - Teil 1: Anforderungen
Spécifications (ISO 10426-1:2000) (ISO 10426-1:2000)
This European Standard was approved by CEN on 18 February 2000.
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 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 Management Centre has the same status as the official
versions.
CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece,
Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, 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
© 2000 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN ISO 10426-1:2000 E
worldwide for CEN national Members.

Page 2
CORRECTED  2001-12-05
Foreword
The text of the International Standard ISO 10426-1:2000 has been prepared by Technical Committee
ISO/TC 67 "Materials, equipment and offshore structures for petroleum and natural gas industries" in
collaboration with Technical Committee CEN/TC 12 "Materials, equipment and offshore structures for
petroleum 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 September 2000, and conflicting national standards
shall be withdrawn at the latest by September 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, Czech Republic,
Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands,
Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom.
Endorsement notice
The text of the International Standard ISO 10426-1:2000 was approved by CEN as a European
Standard without any modification.
NOTE: Normative references to International Standards are listed in annex ZA (normative).

Page 3
Annex ZA
(normative)
Normative references to international publications with their corresponding European
publications
This European Standard incorporates, by dated or undated reference, provisions from other publications.
These normativereferences are cited at the appropriate places in the text, and the publications are listed
hereafter. For dated references, subsequent amendments to or revisions of any of these publications
apply to this European Standard only when incorporated in it by amendment or revision. For undated
references the latest edition of the publication referred to applies (including amendments).
NOTE Where an International Publication has been modified by common modifications, indicated by (mod.), the
relevant EN/HD applies.
Publication Year Title EN/HD Year
ISO 13500 1998 Petroleum and natural gas industries EN ISO 13500 1998
- Drilling fluid materials -
Specifications and tests
INTERNATIONAL ISO
STANDARD 10426-1
First edition
2000-03-15
Petroleum and natural gas industries —
Cements and materials for well
cementing —
Part 1:
Specification
Industrie du pétrole et du gaz naturel — Ciments et matériaux de
cimentation des puits —
Partie 1: Spécifications
Reference number
ISO 10426-1:2000(E)
©
ISO 2000
ISO 10426-1:2000(E)
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ii © ISO 2000 – All rights reserved

ISO 10426-1:2000(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 C 109).20
9.4 Compressive strength acceptance criteria .21
10 Thickening-time tests.22
10.1 Apparatus .22
10.2 Calibration .27
10.3 Procedure .30
10.4 Thickening time and consistency .36
10.5 Specification acceptance requirements.36
11 Marking .36
12 Packing .37
13 Bentonite .37
Annex A (informative) Calibration procedures for thermocouples, temperature-measuring systems and
controllers .38
Bibliography.40
ISO 10426-1:2000(E)
Foreword
ISO (the International Organisation for Standardisation) 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 organisations, 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 standardisation.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 3.
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 part of ISO 10426 may be the subject of
patent rights. ISO shall not be held responsible for identifying any or all such patent rights.
International Standard ISO 10426-1 was prepared by Technical Committee ISO/TC 67, Materials, equipment and
offshore structures for petroleum and natural gas industries, Subcommittee SC 3, Drilling and completion fluids,
and well cements.
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: Recommended practice for testing of well cement
Annex A of this part of ISO 10426 is for information only.
iv © ISO 2000 – All rights reserved

ISO 10426-1:2000(E)
Introduction
This part of ISO 10426 is based on API Specification 10A, 22nd edition, January 1995.
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 10426-1:2000(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
may be used in the manufacture of cement of these classes. Suitable set-modifying agents may 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 normative documents contain provisions which, through reference in this text, constitute provisions of
this part of ISO 10426. For dated references, subsequent amendments to, or revisions of, any of these publications
do not apply. However, parties to agreements based on this part of ISO 10426 are encouraged to investigate the
possibility of applying the most recent editions of the normative documents indicated below. For undated
references, the latest edition of the normative document referred to applies. Members of ISO and IEC maintain
registers of currently valid International Standards.
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 C 109/C 109M, Standard test method for compressive strength of hydraulic cement mortars (using 2-in or
[50-mm] cube specimens).
ASTM C 114, Standard test methods for chemical analysis of hydraulic cement.
ASTM C 115, Standard test methods for fineness of Portland cement by the turbidimeter .
ASTM C 183, Standard practice for sampling and the amount of testing of hydraulic cement.
ASTM C 204, Standard test method for fineness of Portland cement by air permeability apparatus.
ASTM C 465, Standard specification for processing additions for use in the manufacture of hydraulic cements.
ASTM E 220, Standard test method for calibration of thermocouples by comparison techniques.
ASTM E 1404, Standard specification for laboratory class conical flasks.
ISO 10426-1:2000(E)
DIN 12385, Laboratory glassware, conical flasks, wide neck.
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.
EN 196-21, Methods of testing cement — Part 21: Determination of the chloride, carbon dioxide and alkali content
of cement.
3 Terms and definitions
For the purposes of this part of ISO 10426, 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
2 © ISO 2000 – All rights reserved

ISO 10426-1:2000(E)
3.10
consistometer
device used to measure the thickening time of a cement slurry under temperature and pressure
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 will remain 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 C 465.
This product is intended for use when special properties are not required. Available only in ordinary (O) Grade
(similar to ASTM C 150, 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
ISO 10426-1:2000(E)
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 C 465.
This product is intended for use when conditions require moderate or high sulfate-resistance. Available in both
moderate sulfate-resistant (MSR) and high sulfate-resistant (HSR) Grades (similar to ASTM C 150, 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 C 465.
This product is intended for use when conditions require high early strength. Available in ordinary (O),
moderate sulfate-resistant (MSR) and high sulfate-resistant (HSR) Grades (similar to ASTM C 150, 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 C 465. 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. 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 C 465. 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. 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 C 465. 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. Available in
moderate sulfate-resistant (MSR) and high sulfate-resistant (HSR) Grades.
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.
This product is intended for use as a basic well cement. Available in moderate sulfate-resistant (MSR) and
high sulfate-resistant (HSR) Grades.
4 © ISO 2000 – All rights reserved

ISO 10426-1:2000(E)
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.
This product is intended for use as a basic well cement. 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 C 114 (or EN 196-2,
EN 196-21).
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 10426-1:2000(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 (C S) maximum, %
NA NR NR NR
58 58
b b
minimum, % NA NR NR NR
48 48
(3)
NA 8 8 8 8 8
Tricalcium aluminate (C A), maximum %
Total alkali content, expressed as sodium oxide (Na O)
c c
NA NR NR NR
0,75 0,75
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 (C S) maximum, %
NA NR NR NR
65 65
b b
minimum, % NA NR NR NR
48 48
Tricalcium aluminate (C A), maximum, % b b b b b
NA
3 3 3 3 3 3
Tetracalcium aluminoferrite (C AF)plus twice the
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)
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 2000 – All rights reserved

ISO 10426-1:2000(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 m /kg) 150 160 220 NR NR NR NR NR
Air permeability (specified surface, minimum m /kg) 280 280 400 NR NR NR NR NR
Free fluid content, maximum % (clause 8) NR NR NR NR NR NR 5,5 5,5
Compressive Schedule Final curing Final curing Minimum compressive strength
strength test number, temp. pressure
MPa (psi)
(8-h curing time) Table 6 °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 (3 000) NR NR NR 3,4 NR NR NR NR
(500)
8S 143 (290) 20,7 (3 000) NR NR NR NR 3,4 NR NR NR
(500)
9S 160 (320) 20,7 (3 000) NR NR NR NR NR 3,4 NR NR
(500)
Compressive Schedule Final curing Final curing Minimum compressive strength
strength test number, temp. pressure
MPa (psi)
(24-h curing Table 6
°C (°F) MPa (psi)
time) (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 (3 000) NR NR NR 6,9 6,9 NR NR NR
(1 000) (1 000)
6S 110 (230) 20,7 (3 000) NR NR NR 13,8 NR 6,9 NR NR
(2 000) (1 000)
8S 143 (290) 20,7 (3 000) NR NR NR NR 13,8 NR NR NR
(2 000)
9S 160 (320) 20,7 (3 000) NR NR NR NR NR 6,9 NR NR
(1 000)
ISO 10426-1:2000(E)
Table 2 — Summary of physical and performance requirements (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
through 13
a
period) B
c
4 30 90min. 90min. 90min. 90min. NR NR NR NR
5 30 NRNR NRNR NRNR 90min.90min.
5 30 NRNR NRNR NRNR 120max.120max.
6 30 NR NR NR 100 min. 100 min. 100 min. NR NR
8 30 NR NR NR NR 154 min. NR NR NR
9 30 NR NR NR NR NR 190 min. NR NR
a
Bearden units of consistency (B ) obtained on a pressurized consistometer as defined in clause 10 and calibrated as per the same clause.
c
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 2000 – All rights reserved

ISO 10426-1:2000(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
D, E, F
Pressure cured 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 C 183 (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 C 115 for
the turbidimeter test or the procedure in ASTM C 204 (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 10426-1:2000(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 Weights
Weights shall be accurate within the tolerance shown in Table 4. On beam-type scales where the weights are on
the beam, the indicated weights shall conform to the requirements given in 7.1.1.
Table 4 — Permissible variation in weights
Weight Permissible variation
g g
� 0,5
� 0,35
� 0,30
� 0,20
� 0,15
� 0,10
7.1.3 Sieves
A No. 20 wire cloth sieve (openings 850�m), 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 shall be constructed of
durable material. It shall be weighed prior to use and replaced with an unused blade when 10 % mass loss has
occurred. The mixing container shall be of suitable construction.
Figure 1 — Examples of typical cement-mixing devices
10 © ISO 2000 – All rights reserved

ISO 10426-1:2000(E)
7.2 Procedure
7.2.1 Sieving
Prior to mixing, the cement shall be sieved as described in ASTM C 183.
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 �500r/min(200r/s � 8,3 r/s)
for 35 s �1s.
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 10426-1:2000(E)
Key
1 Cap lock nut
2 Centre lock reverse jam nut
3Dial
4 Pointer
5 Dial and base assembly
6Spring
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 2000 – All rights reserved

ISO 10426-1:2000(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 10426-1:2000(E)
Dimensions in millimetres [inches]
Key
1 2 slots 180° apart
2 Fill-level indicating groove
3 Pivot bearing
Tolerances mm [inches]
,x [,xx] � 0,25 [0,010]
,xx [,xxx] � 0,13 [0,005]
angles � 1�
Figure 4 — Container for typical atmospheric pressure consistometer
14 © ISO 2000 – All rights reserved

ISO 10426-1:2000(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.
Tolerances mm [inches]
,x [,xx] � 0,25 [0,010]
,xx [,xxx] � 0,13 [0,005]
angles � 1�
Figure 5 — Paddle for typical atmospheric pressure consistometer
ISO 10426-1:2000(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 E 1404, 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 E 220 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 2000 – All rights reserved

ISO 10426-1:2000(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. Seal the flask with a self-sealing film to prevent
evaporation.
8.3.6 Set the slurry-filled flask on a surface that is nominally level and vibration-free. The air temperature to
which the slurry-filled flask is exposed shall be 22,8 �C � 2,8 �C(73 �F � 5 �F). The temperature sensor for
measuring air temperature shall meet the requirements of 8.2.1. Let the slurry-filled flask remain undisturbed for a
period of 2 h � 5min.
8.3.7 At the end of 2 h, remove the supernatant fluid that has developed with a pipet or syringe. Measure the
volume of supernatant fluid to an accuracy of � 0,1 ml and record it as millilitres free fluid.
8.3.8 Convert the millilitres free fluid to a percentage of starting slurry volume (~400 ml depen
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