oSIST prEN ISO 27917:2026

SLOVENSKI STANDARD
01-april-2026
Zajemanje, transport in shranjevanje ogljikovega dioksida - Slovar - Presečni izrazi
(ISO/DIS 27917:2026)
Carbon dioxide capture, transportation and storage - Vocabulary - Cross cutting terms
(ISO/DIS 27917:2026)
CO2-Abscheidung, -Transport und ‑Speicherung - Vokabular - Übergreifende Begriffe
(ISO/DIS 27917:2026)
Carbon dioxide capture, transportation and storage - Vocabulary - Cross cutting terms
(ISO/DIS 27917:2026)
Ta slovenski standard je istoveten z: prEN ISO 27917
ICS:
01.040.13 Okolje. Varovanje zdravja. Environment. Health
Varnost (Slovarji) protection. Safety
(Vocabularies)
13.020.40 Onesnaževanje, nadzor nad Pollution, pollution control
onesnaževanjem in and conservation
ohranjanje
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

DRAFT
International
Standard
ISO/DIS 27917
ISO/TC 265
Carbon dioxide capture,
Secretariat: SCC
transportation and storage —
Voting begins on:
Vocabulary — Cross cutting terms
2026-02-17
ICS: 01.040.13; 13.020.40
Voting terminates on:
2026-05-12
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Reference number
ISO/DIS 27917:2026(en)
DRAFT
ISO/DIS 27917:2026(en)
International
Standard
ISO/DIS 27917
ISO/TC 265
Carbon dioxide capture,
Secretariat: SCC
transportation and storage —
Voting begins on:
Vocabulary — Cross cutting terms
ICS: 01.040.13; 13.020.40
Voting terminates on:
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
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Published in Switzerland Reference number
ISO/DIS 27917:2026(en)
ii
ISO/DIS 27917:2026(en)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
3.1 General terms and definitions relating to carbon dioxide capture, transportation and
storage .1
3.2 General terms and definitions relating to CO .4
3.3 General terms and definitions relating to monitoring and measuring performance in
CCS .7
3.4 General terms and definitions relating to risk .8
3.5 General terms and definitions relating to relationship with stakeholders .10
Annex A (Informative) General Definitions .11
Annex B (informative) List of acronyms . 14
Annex C (informative) CCS project life cycle .15
Bibliography .16
Index . 17

iii
ISO/DIS 27917:2026(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 documents 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).
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. Details of any patent
rights identified during the development of the document will be in the Introduction and/or on the ISO list of
patent declarations received (see www.iso.org/patents).
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and
expressions related to conformity assessment, as well as information about ISO's adherence to the World
Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following URL:
www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 265, Carbon dioxide capture, transportation
and storage.
iv
ISO/DIS 27917:2026(en)
Introduction
The objectives of the document are the following:
— to provide a comprehensive list of terms and their definitions for carbon dioxide capture, transportation
and geological storage including through enhanced oil (or gas) recovery (EOR) operation to facilitate
communication among:
— experts involved in the development of ISO standards on carbon dioxide capture, transportation and
geological storage;
— other carbon dioxide capture, transportation and geological storage stakeholders;
— to provide the basis for common understanding for all future ISO TC 265 documents for carbon dioxide
capture, transportation and storage.
The term “sequestration” has been used by some countries and organizations instead of “storage” (e.g. the
international “Carbon Sequestration Leadership Forum”). The two terms are considered synonymous, and
only “storage” is used in this document.
The chemical symbol “CO ” is synonymous with “carbon dioxide”. Accordingly, the two ways of writing out
“carbon dioxide” and “CO ” are used interchangeably in this document.
v
DRAFT International Standard ISO/DIS 27917:2026(en)
Carbon dioxide capture, transportation and storage —
Vocabulary — Cross cutting terms
1 Scope
This document defines a list of cross-cutting terms commonly used in the field of carbon dioxide capture,
transportation and geological sub-surface storage including through storage in association with enhanced
oil recovery (EOR) operations.
This document only deals with CO geological sub-surface storage.
The terms are classified as follows:
— general terms and definitions relating to carbon dioxide;
— general terms and definitions relating to carbon dioxide capture, transportation and storage;
— general terms and definitions relating to monitoring and measuring performance in carbon dioxide
capture, transportation and geological storage;
— general terms and definitions relating to risk;
— general terms and definitions relating to relationships with stakeholders;
A list of the main acronyms used is given in Annex A.
2 Normative references
There are no normative references in this document.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1 General terms and definitions relating to carbon dioxide capture, transportation and
storage
3.1.1
carbon dioxide capture and geological storage
CCS
process consisting of the separation of CO from the atmosphere or from industrial and energy-related
sources, transportation and injection into a geological formation, resulting in long term isolation from the
atmosphere
Note 1 to entry: CCS is often referred to as Carbon Capture and Storage. This terminology is not encouraged because it
is inaccurate: the objective is the capture of carbon dioxide and not the capture of carbon. Tree plantation is another
form of carbon capture that does not describe precisely the physical process of removing CO from industrial emission
sources.
ISO/DIS 27917:2026(en)
Note 2 to entry: The term "sequestration" is also used alternatively to "storage". The term "storage" is preferred since
“sequestration” is more generic and can also refer to biological processes (absorption of carbon by living organisms).
Note 3 to entry: Long term means the minimum period necessary for geological storage of CO to be considered an
effective and environmentally safe climate change mitigation option.
Note 4 to entry: The term Carbon dioxide Capture, Utilization (or use) and Storage (CCUS) includes the concept that
isolation from the atmosphere could be associated with a beneficial outcome. CCUS is embodied within the definition
of CCS to the extent that long term isolation of the CO occurs through storage within geological formations. CCU is
Carbon Capture and Utilization (or use) without storage within geological formations.
Note 5 to entry: CCS should also ensure long term isolation of CO from oceans, lakes, potable water supplies and other
natural resources.
3.1.2
CCS project life cycle
entirety of phases of a CCS project from concept through to post-closure
Note 1 to entry: The CCS project life cycle includes mainly concept, design, obtaining permit, construction, operation,
monitoring, measurement and verification, decommissioning, closure and post-closure (see Annex C).
3.1.3
intermittency
lack of continuity in operation, as measured by the frequency or extent to which a process or installation is
stopped or unavailable
Note 1 to entry: Intermittency includes variable CO flows among project components.
3.1.4
geological storage complex
subsurface geological strata that comprise the storage unit (3.1.2) and the confining unit (3.1.19), and
extending laterally to the defined limits of the CO storage site
Note 1 to entry: Limits can be defined by natural geological boundaries, regulation or legal rights.
3.1.5
EOR Complex
project reservoir, trap, and such additional surrounding volume in the subsurface as defined by the operator
within which injected CO will remain in safe, long-term containment (3.1.6)
3.1.6
safe, long-term containment
for the period necessary to be considered secure by the system under which the quantification is being
implemented
3.1.7
geological storage
safe, long-term containment (3.1.6) of CO stream in subsurface geological formations
[SOURCE: ISO 27914:2026, 3.14]
3.1.8
carbon dioxide (CO ) plume
region within geologic strata where CO is present in free phase
Note 1 to entry: In saline aquifers, CO as a free phase includes typically CO as a separate buoyant fluid phase. It may
2 2
also include CO dissolved in formation water.
Note 2 to entry: In depleted natural gas reservoirs, a CO plume may be a part of a porous reservoir with CO
2 2
concentrations in the gas phase, exceeding initial concentrations in the reservoir
Note 3 to entry: In environmental impact assessments and risk management, the term CO plume can also refer to an
area or volume in the atmosphere or in aquatic environments into which CO is dispersed or dissolved
ISO/DIS 27917:2026(en)
[SOURCE: ISO 27914:2026, 3.4 Notes added]
3.1.9
carbon dioxide capture and geological storage project
CCS project
consists of one or more connected CO capture systems, transportation systems, and storage or geological
storage systems
Note 1 to entry: Each system (capture, transportation, or storage) might be operated by independent operators.
Note 2 to entry: The term “integrated CCS project” is sometimes used to identify a project that includes capturing
CO from a point source or the atmosphere, transporting it to storage or a geological storage site where it is injected
into deep geologic formations (storage complex), and monitoring (3.3.1) to verify that it remains isolated from the
atmosphere.
Note 3 to entry: For more information on
— CO capture systems, see ISO/TR 27912,
— CO transportation systems, see ISO 27913, and
— CO geological storage systems, see ISO 27914.
[SOURCE: ISO 27914:2017, 3.56]
3.1.10
CO capture
separation of CO in such a manner as to produce a concentrated stream of CO that can readily be
2 2
transported for storage
[SOURCE: ISO TR 27912;2016, 3.16]
3.1.11
carbon dioxide capture and storage network
CCS network
connections of multiple CO sources and storage sites
[SOURCE: ISO TR 27925;2023 3.1]
3.1.12
carbon dioxide capture and storage system
CCS system
combination of the capture, transportation and storage components considered as a single entity
[SOURCE: ISO TR 27925;2023 3.3]
3.1.13
flow assurance
engineering discipline that is required to understand the behavior of fluids inside pipelines, at flowing and
static conditions
Note 1 to entry: The flow assurance provides input to design activities, such as pipeline design or risk analysis and
operating philosophy development.
[SOURCE: ISO 27913;2024 3.13]
3.1.14
hydraulic capacity
maximum flow rate achievable in a system for a given pressure loss and given mechanical and operating
constraints
[SOURCE: ISO 27913;2024 3.15]
ISO/DIS 27917:2026(en)
3.1.15
CCS project component
assemblage of technical or geotechnical installations and natural features of subsurface geological systems
that are separate in terms of physical space, technical disciplines, industrial practice and dominating
physico-chemical processes
3.1.16
chemical component or constituent
individual molecular parts of a fluid or stream
3.1.17
CO carrier
cargo ship or barge constructed or adapted and used for the carriage of CO as cargo
[SOURCE: ISO TR 27929;2024 3.4]
3.1.18
intermediate storage
storage of CO volumes before being loaded to a ship and storage after being offloaded from a ship
[SOURCE: ISO TR 27929;2024 3.13]
3.1.19
confining unit
geological strata that are part of a geological storage complex (3.1.4) and effectively restrict migration of
fluids out of the storage unit (3.1.20) and leakage (3.2.14) out of the geological storage complex
Note 1 to entry: Described in reservoir engineering as caprock and in hydrogeology as aquitard or aquiclude.
3.1.20
storage unit
geological stratum (or strata) into which CO is injected and contained for the purpose of geological storage
[SOURCE: ISO 27914:2026, 3.50]
3.2 General terms and definitions relating to CO
3.2.1
supercritical CO
CO at pressures and temperatures above both the critical pressure and critical temperature
3.2.2
dense phase CO
CO or CO stream (3.2.11) in the single-phase fluid state above a density of 500 kg/m3
2 2
Note 1 to entry: For more details on the dense phase, refer to ISO/TR 27925:2023.
[SOURCE: ISO 27913;2024 3.9 added CO ]
Note 2 to entry: Compression and transport of dense phase CO are commonly achieved using pumps. Compression
and transport at lower densities are commonly achieved with turbo-compressors.
Note 3 to entry: Not all supercritical CO is in a dense phase, and not all dense phase CO is supercritical.
2 2
Note 4 to entry: Figure 1 illustrates pure CO phase diagram and density plots, calculated according to Reference [16],
and plotted as a function of temperature and pressure.

ISO/DIS 27917:2026(en)
Key
1 triple point
2 critical point
3 liquid-gas phase boundary
4 solid-(dense) fluid phase boundary
5 solid-(gaseous) fluid phase boundary
6 critical temperature
7 critical pressure
8 lower operation limit for radial pumps
Figure 1 — Pure CO phase diagram and density plots
Note 5 to entry: The curve defined by Key number 8 is shown as an example illustrating typical operation limits
specific to individual pumps, according to Reference [17].
— Fluid CO in the p-T-range between lines 3, 4 and 6 is often named
...