ISO 23333:2025

Natural gas - Upstream area - Requirements and testing of slick water

This document specifies the requirements, sampling, testing, inspection and accompanying documents of slick water. This document is applicable to fracturing fluid systems used in hydraulic fracturing operations in shale gas.

Titre manque

General Information

• Status: Published
• Publication Date: 09-Oct-2025
• ICS: 75.060 - Natural gas
• Technical Committee: ISO/TC 193/SC 3 - Upstream area
• Drafting Committee: ISO/TC 193/SC 3 - Upstream area
• Current Stage: 6060 - International Standard published
• Start Date: 10-Oct-2025
• Due Date: 28-Sep-2026
• Completion Date: 10-Oct-2025

Overview

ISO 23333:2025 - Natural gas - Upstream area - Requirements and testing of slick water is an international standard that defines performance, sampling, testing, inspection and documentation for slick water fracturing fluids used in hydraulic fracturing for shale gas. It provides harmonized technical criteria to support producers, suppliers, service companies, testing laboratories and regulators in ensuring consistent quality and safe use of slick water in upstream natural gas operations.

Key Topics and Requirements

The standard sets clear, testable requirements and references established test methods:

• Scope: Applicable to fracturing fluid systems used in hydraulic fracturing operations in shale gas.
• Performance limits:
  • pH: 6.0 to 9.0.
  • Residue content: ≤ 150 mg/l.
  • Drag reduction: ≥ 60% (measured per ISO 7055).
  • Dissolution time: additives dissolve within 40 s.
  • Kinematic viscosity: < 5.0 mm²/s (tested per ISO 3104).
• Compatibility: No precipitation or flocculation under room and reservoir test conditions (detailed method in Annex A).
• Sampling:
  • Laboratory: at least three replicate samples per batch.
  • Field: continuous-mix samples every 5 minutes, minimum three samples; quartering method for reduction.
  • Sample retention: split into two containers; retain reference sample up to 3 months; testing preferably within 24 h.
• Testing methods:
  • pH per ISO 13503-3.
  • Drag reduction per ISO 7055.
  • Residue content and dissolution time per Annexes B and C.
  • Kinematic viscosity per ISO 3104.
• Inspection & acceptance:
  • Full-item inspection for laboratory samples; field inspections must include pH, compatibility and kinematic viscosity.
  • Re-inspection rules if initial tests fail.
• Accompanying documents: product qualification certificate, quality inspection report, Material Safety Data Sheet (MSDS).

Applications and Users

ISO 23333:2025 is practical for:

• Shale gas producers and well operators setting procurement and acceptance criteria for slick water.
• Chemical suppliers and service companies developing or supplying fracturing fluids.
• Third‑party testing laboratories performing QA/QC and compliance testing.
• Regulators and project owners establishing contract specifications and environmental/operational controls.
• Use cases include on-site quality control during hydraulic fracturing, product certification, dispute resolution, and international trade of slick water products.

Related standards

Relevant cross-referenced standards include:

• ISO 7055 - Drag reduction determination for slick water
• ISO 3104 - Kinematic viscosity testing
• ISO 13503-3 - pH and completion fluids testing
• ISO 3170 - Manual sampling of hydrocarbon liquids
• ISO 14532 - Natural gas vocabulary

Keywords: ISO 23333:2025, slick water, hydraulic fracturing, shale gas, drag reduction, fracking fluid testing, compatibility testing, residue content, kinematic viscosity, sampling and testing, upstream natural gas.

Standards Content (Sample)

International
Standard
ISO 23333
First edition
Natural gas — Upstream area
2025-10
— Requirements and testing of
slick water
Reference number
© ISO 2025
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
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Published in Switzerland
ii
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
4 Requirements . 2
4.1 pH .2
4.2 Compatibility .2
4.3 Residue content .2
4.4 Drag reduction .2
4.5 Dissolution time.2
4.6 Kinematic viscosity .2
5 Sampling . 2
5.1 General .2
5.2 Laboratory sampling .3
5.3 Field sampling .3
6 Testing. 3
6.1 pH .3
6.2 Compatibility .3
6.3 Residue content .3
6.4 Drag reduction .3
6.5 Dissolution time.3
6.6 Kinematic viscosity .3
7 Inspection . 3
8 Accompanying documents . . 4
Annex A (normative) Compatibility testing . 5
Annex B (normative) Residue content testing. 7
Annex C (normative) Dissolution time testing . 9

iii
Foreword
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This document was prepared by Technical Committee ISO/TC 193, Natural gas, Subcommittee SC 3,
Upstream area.
Any feedback or questions on this document should be directed to the user’s national standards body. A
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iv
Introduction
Unconventional reservoirs, represented by shale gas, have increasingly become a hotspot in the exploration
and development of global oil and gas resources. The success of the shale gas revolution has fundamentally
reshaped the global energy landscape. Economical and efficient development of shale gas has become a key
aspect of the global oil and gas industry.
Volume fracturing technology is the core technique for the economical and efficient development of shale
gas. Slick water, as a type of fracturing fluid that can be mixed and injected on-site, plays a significant role
in the effectiveness of shale gas reservoir transformation using volume fracturing technology. Currently,
besides China and the United States, countries such as Argentina, Australia and Canada are also actively
promoting and applying slick water volume fracturing technology to develop their shale gas resources.
However, differences in technical requirements of slick water among countries hinder global trade
cooperation in this field. To address this issue, this document aims to establish an international standard
for slick water performance requirements. It provides a common technical solution for shale gas producers,
sellers, users, and government agencies in regions rich in shale gas such as Asia-Pacific, North America and
South America. It aims to:
— reduce costs;
— expand market size;
— resolve disputes effectively;
— promote cooperation and usage of slick water technology;
— enhance global cooperation efficiency in shale gas exploration and development;
— foster the large-scale, sound development of the shale gas industry.
Furthermore, it aims to advance the exploration, development and application of global green and low-
carbon
...