FprEN ISO 13503-5

• Abstract:

  ISO 13503-5:2006 provides standard testing procedures for evaluating proppants used in hydraulic fracturing and gravel packing operations. ISO 13503-5:2006 provides a consistent methodology for testing performed on hydraulic fracturing and/or gravel packing proppants. The "proppants" mentioned henceforth in this part of ISO 13503-5:2006 refer to sand, ceramic media, resin-coated proppants, gravel packing media, and other materials used for hydraulic fracturing and gravel-packing operations.; ISO 13503-5:2006 is not applicable for use in obtaining absolute values of proppant pack conductivities under downhole reservoir conditions.

• Status: Not Published
• Publication Date: 17-Mar-2027
• ICS: 75.180.10 - Exploratory, drilling and extraction equipment
• Technical Committee: CEN/TC 12 - Materials, equipment and offshore structures for petroleum and natural gas industries
• Drafting Committee: ISO/TC 67 - ISO/TC 67
• Current Stage: 4599 - Dispatch of FV draft to CMC - Finalization for Vote
• Start Date: 06-Aug-2026
• Completion Date: 06-Aug-2026
• Ref Project: oSIST prEN ISO 13503-5:2026 - Oil and gas industries including lower carbon energy - Completion fluids and materials - Part 5: Measuring conductivity of proppants (ISO/DIS 13503-5:2026)

• Consolidated By: ISO/FDIS 13503-5 - Oil and gas industries including lower carbon energy — Completion fluids and materials — Part 5: Measuring conductivity of proppants
• Effective Date: 28-Feb-2026
• Revises: EN ISO 13503-5:2006 - Petroleum and natural gas industries - Completion fluids and materials - Part 5: Procedures for measuring the long-term conductivity of proppants (ISO 13503-5:2006)
• Effective Date: 18-Feb-2026

FprEN ISO 13503-5 is a CEN draft standard in the Oil and gas industries including lower carbon energy series. It specifies how to measure the conductivity of proppants used in hydraulic fracturing and gravel packing, and it supplements API RP 19D, 2nd edition (2021). The document is meant for test laboratories, proppant suppliers, and completion engineers who need a common method for comparing materials.

What does FprEN ISO 13503-5 specify?

FprEN ISO 13503-5 specifies testing procedures for evaluating proppants in hydraulic fracturing and gravel packing operations. Its scope covers sand, ceramic media, resin-coated proppants, gravel packing media, and similar materials used in those operations.

The document is organized into a foreword, three main clauses, and a bibliography. Clause 1 gives the scope, Clause 2 lists the normative reference, and Clause 3 gives the supplements to API RP 19D, including general requirements, cell loading, and data acquisition.

FprEN ISO 13503-5 is not intended for obtaining absolute values of proppant pack conductivities under downhole reservoir conditions. In practice, that means the method is for consistent comparative testing, not for claiming a direct field value from a laboratory result.

What are the key requirements of FprEN ISO 13503-5?

FprEN ISO 13503-5 works by taking API RP 19D as the base method and replacing selected steps with updated requirements. The document therefore matters most where a laboratory needs to follow a standard procedure but also apply the ISO-specific exceptions.

General application of the method

Clause 3.1 says the requirements of API RP 19D, 2nd edition (2021), apply except for the items specifically replaced in this document and in Annex C, Figure C.7. In practice, users must follow the base procedure and then check the ISO exceptions before running a test.

Loading dry proppant into the cell(s)

Clause 3.2.1 introduces a new levelling device for loading dry proppant into the cell(s). The proppant is levelled by moving the scraper plate and adjusting the device along the cell walls.

This matters because the loading method affects how evenly the proppant pack forms. The note also says the proppant shall not be packed by vibration or tamping, which helps avoid segregation of the material.

Loading the cell(s) in the load frame

Clause 3.2.2 replaces part of the API load-frame procedure with a staged pressurization sequence. The pressure is increased in controlled steps to the specified closure stress range and back-pressure adjustment.

In practice, the laboratory must control the ramp rate and pressure transitions carefully. That is important because the way the pack is loaded can influence the measured conductivity.

Acquiring data

Clause 3.3 replaces part of the API data acquisition procedure. It requires stress increases in 13,80 MPa increments, an initial absolute stress hold for a minimum and maximum time window, and several stress points during pressurization to observe the conductivity trend.

This means the test is not just a single final reading. The lab records conductivity at selected stresses so it can track how the proppant pack responds as load increases.

Time and stress conditions

Clause 3.3 also states that the initial stress is held at the required temperature, with back-pressure maintained in the stated range. The stress must then be held long enough for single-point conductivity to be valid.

For users, this is a control issue: the recorded conductivity is only meaningful if the test duration, temperature, stress history, and back-pressure are all managed as specified.

What terms does FprEN ISO 13503-5 define?

• Proppants - Sand, ceramic media, resin-coated proppants, gravel packing media, and similar materials placed to keep fractures or packed intervals open.
• Hydraulic fracturing - A completion operation in which fluid creates or extends fractures so the proppant can support flow paths.
• Gravel packing - A completion method that places granular material to help control sand production while keeping flow open.
• Conductivity - The ability of the proppant pack to let fluid pass through it under load.
• Closure stress - The compressive stress applied to the proppant pack during the conductivity test.
• Back-pressure - Pressure maintained on the fluid side during the test to match the stated procedure.
• Load frame - The equipment that applies the required stress to the cell containing the proppant.

Who uses FprEN ISO 13503-5?

FprEN ISO 13503-5 is used by laboratories that test proppant performance, by manufacturers of sand, ceramic media, and resin-coated proppants, and by oil and gas completion teams that specify or compare materials. It is also relevant to quality control staff and buyers who need a common test basis when reviewing supplier data.

What changed in FprEN ISO 13503-5 from the previous edition?

FprEN ISO 13503-5 cancels and replaces ISO 13503-5:2006 and incorporates the amendment to that edition. The foreword states that the technical requirements were previously identical to API RP 19D, but the current edition updates the reference to API RP 19D, 2nd edition (2021), and adds supplementary content.

The foreword lists three main changes:

• a new levelling device is used,
• the stress increasing rate is reduced to 100 kPa/min ± 10 kPa/min,
• additional stress points are added during pressurization.

Which standards are used with FprEN ISO 13503-5?

The normative reference named in FprEN ISO 13503-5 is API RP 19D, 2nd edition (2021), Measuring Conductivity of Proppants. This is the base procedure that the ISO document supplements and modifies where needed.

What does the FprEN ISO 13503-5 document contain?

FprEN ISO 13503-5 contains one figure for the levelling device, plus detailed procedural text for loading the cell(s) and acquiring conductivity data. It also includes a bibliography with two technical references on proppant conductivity and correlations.

The document’s structure is practical rather than theoretical. It is written to support laboratory setup, test execution, and comparison of results across users following the same procedure.

SLOVENSKI STANDARD
01-julij-2026
Naftna in plinska industrija, vključno z nizkoogljično energijo - Tekočine in
materiali za zaključna dela - 5. del: Merjenje prevodnosti podpornih materialov
(ISO/DIS 13503-5:2026)
Oil and gas industries including lower carbon energy - Completion fluids and materials -
Part 5: Measuring conductivity of proppants (ISO/DIS 13503-5:2026)
Öl- und Gasindustrie einschließlich kohlenstoffarmer Energieträger -
Komplettierungsflüssigkeiten und Materialien - Teil 5: Messung der Leitfähigkeit von
Stützmaterialien (ISO/DIS 13503-5:2026)
Titre manque — Partie 5: Titre manque
Ta slovenski standard je istoveten z: prEN ISO 13503-5
ICS:
75.100 Maziva Lubricants, industrial oils and
related products
75.180.10 Oprema za raziskovanje, Exploratory, drilling and
vrtanje in odkopavanje extraction equipment
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
International
Standard
ISO/DIS 13503-5
ISO/TC 67/SC 3
Oil and gas industries including
Secretariat: UNI
lower carbon energy — Completion
Voting begins on:
fluids and materials —
2026-05-05
Part 5:
Voting terminates on:
2026-07-28
Measuring conductivity of
proppants
ICS: 75.100; 75.180.10
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,
TECHNOLOGICAL, COMMERCIAL AND
USER PURPOSES, DRAFT INTERNATIONAL
STANDARDS MAY ON OCCASION HAVE TO
ISO/CEN PARALLEL PROCESSING
BE CONSIDERED IN THE LIGHT OF THEIR
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
NATIONAL REGULATIONS.
RECIPIENTS OF THIS DRAFT ARE INVITED
TO SUBMIT, WITH THEIR COMMENTS,
NOTIFICATION OF ANY RELEVANT PATENT
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION.
Reference number
ISO/DIS 13503-5:2026(en)
DRAFT
ISO/DIS 13503-5:2026(en)
International
Standard
ISO/DIS 13503-5
ISO/TC 67/SC 3
Oil and gas industries including
Secretariat: UNI
lower carbon energy — Completion
Voting begins on:
fluids and materials —
Part 5:
Voting terminates on:
Measuring conductivity of
proppants
ICS: 75.100; 75.180.10
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
STANDARDS MAY ON OCCASION HAVE TO
ISO/CEN PARALLEL PROCESSING
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
BE CONSIDERED IN THE LIGHT OF THEIR
the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below
POTENTIAL TO BECOME STANDARDS TO
WHICH REFERENCE MAY BE MADE IN
or ISO’s member body in the country of the requester.
NATIONAL REGULATIONS.
ISO copyright office
RECIPIENTS OF THIS DRAFT ARE INVITED
CP 401 • Ch. de Blandonnet 8
TO SUBMIT, WITH THEIR COMMENTS,
CH-1214 Vernier, Geneva
NOTIFICATION OF ANY RELEVANT PATENT
Phone: [phone]
RIGHTS OF WHICH THEY ARE AWARE AND TO
PROVIDE SUPPORTING DOCUMENTATION.
Email: [e-mail]
Website: www.iso.org
Published in Switzerland Reference number
ISO/DIS 13503-5:2026(en)
ii
ISO/DIS 13503-5:2026(en)
Contents Page
Foreword .iv
1 Scope . 1
2 Normative references . 1
3 Supplements to API RP 19D, 2nd edition (2021) . 1
3.1 General requirements .1
3.2 Procedure for Loading the Cell(s) .1
3.2.1 Loading Dry Proppant into the Cell(s) .1
3.2.2 Loading Cell(s) in the Load Frame .3
3.3 Acquiring Data .3
Bibliography . 4

iii
ISO/DIS 13503-5:2026(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, Part 1. In particular, the different approval criteria needed for the different types
of ISO document should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect
...