ISO 15156-1:2020

Overview

ISO 15156-1:2020 - "Petroleum and natural gas industries - Materials for use in H2S-containing environments in oil and gas production - Part 1" provides general principles for selecting and qualifying metallic materials that resist cracking in hydrogen‑sulfide (H2S) environments. It applies to equipment used in oil and gas production and natural‑gas sweetening where failure could endanger people or the environment. This Part 1 supplements design codes and standards and addresses all H2S‑related cracking mechanisms (for example, sulfide stress cracking, stress corrosion cracking, hydrogen‑induced cracking, galvanically induced hydrogen stress cracking).

Key topics and requirements

• Scope and applicability: Guidance is targeted at production and sweetening plants; it is not necessarily applicable to refining or downstream equipment. Table 1 of the standard lists applicable equipment and exclusions (including pressure‑related exclusions).
• Cracking mechanisms covered: sulfide stress cracking (SSC), stress corrosion cracking (SCC), hydrogen‑induced cracking (HIC), stepwise cracking, stress‑oriented hydrogen‑induced cracking (SOHIC), soft‑zone cracking, and galvanically induced hydrogen stress cracking (GHSC).
• Material selection principles: Framework to evaluate service conditions (H2S exposure, pressure, temperature, pH, loading) to enable appropriate material choices for cracking resistance.
• Qualification routes: Materials can be qualified by documented field experience or by laboratory testing. Requirements include material description and documentation, sampling, selection of test methods, test conditions and acceptance criteria.
• Design method relevance: Intended primarily for equipment designed using load‑controlled methods; clause 5 addresses strain‑based design considerations.
• Updated definitions and thermodynamics: The 2020 edition includes new definitions (e.g., GHSC, fugacity) and expanded guidance on factors affecting susceptibility, including use of H2S fugacity and non‑ideal thermodynamic considerations.

Applications and users

ISO 15156-1:2020 is used for:

• Selecting and qualifying carbon and low‑alloy steels, corrosion‑resistant alloys (CRAs), and other metallics for wells, flowlines, processing equipment, artificial lift, and natural‑gas treatment.
• Risk mitigation against costly failures and safety/environmental incidents in H2S service. Primary users:
• Materials and corrosion engineers
• Design and mechanical engineers in oil & gas production
• Procurement/specification writers and inspection teams
• Operators and asset integrity managers
• Regulators and auditors referencing industry best practice

Related standards

• ISO 15156-2:2020 - Cracking‑resistant carbon and low‑alloy steels and cast irons
• ISO 15156-3:2020 - Cracking‑resistant CRAs and other alloys
• NACE MR0175 (historical alignment) and test methods like NACE TM0177 / TM0284 are commonly referenced for laboratory qualification.

Note: ISO 15156-1 helps avoid H2S‑related cracking but does not guarantee immunity; equipment users retain responsibility to select materials suitable for intended service.