ISO 25206-1:2026

International
Standard
ISO 25206-1
First edition
Oil and gas industries including
2026-09
lower carbon energy —
Enhanced oil recovery terms and
definitions —
Part 1:
General vocabulary
Industries du pétrole et du gaz, y compris les énergies à
faible teneur en carbone — Termes et définitions relatifs à la
récupération améliorée des hydrocarbures —
Partie 1: Vocabulaire général
Reference number
© ISO 2026
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Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3  Terms and definitions . 1
3.1 Basic concepts .1
3.2 Terms related to thermal recovery methods .2
3.3 Terms related to gas flooding methods .2
3.4 Terms related to chemical flooding methods .3
3.5 Terms related to microbial enhanced oil recovery methods .3
Bibliography . 5
Index . 6

iii
Foreword
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This document was prepared by Technical Committee ISO/TC 67, Oil and gas industries including lower carbon
energy, Subcommittee SC 10, Enhanced oil recovery.
A list of all parts in the ISO 25206 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

iv
Introduction
As enhanced oil recovery (EOR) technologies continue to advance and international collaborative projects
increase in number, there is a growing global demand for international standardization in this field. As a
universal technical language, terminology standards play a foundational role in international collaboration
by clearly defining the scope of the field and delineating boundaries with related disciplines.
To maintain terminological coherence across international EOR standards and to prevent conflicts in
application arising from ambiguous or contradictory definitions, coordinated efforts in standardization are
essential. The ISO 25206 series is being developed to establish a coherent framework of mutually reinforcing
definitions, ensuring conceptual alignment across all relevant international standards. This systematic
approach guarantees that precisely defined common terminology forms the essential basis for both the
understanding and implementation of EOR standards worldwide.
Based on the displacement medium and underlying mechanism, EOR is generally classified into the following
main types:
— thermal recovery;
— gas flooding;
— chemical flooding;
— microbial enhanced oil recovery.
This document provides general terms and definitions related to EOR, including fundamental concepts
covering the field and its subdivisions, as well as terms describing the major EOR technologies and their
associated processes. More specialized terminology for each specific category is defined in other parts of
the ISO 25206 series.
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