ISO 28781:2010

Overview

ISO 28781:2010 specifies requirements for subsurface barrier valves and related equipment used in the petroleum and natural gas industries. The standard covers design, design validation, manufacturing, functional evaluation, repair/redress, handling and storage for valve types that create a barrier in the tubular to isolate the formation or support pre‑ and post‑production/injection activities. It explicitly states that subsurface barrier valves are not intended as emergency or fail‑safe safety devices and excludes installation, maintenance, external control systems and connections to the well conduit.

Key contextual notes:

• The standard is structured around six types of barrier valves to reflect different functionality.
• Two quality grades (Q1 highest, Q2 minimum) and three design‑validation grades (V1 most stringent to V3 minimum) let users select appropriate assurance levels.
• Several annexes are normative (B, C, D, E) and others informative (A, F, G, H), providing validation, testing and application guidance.

Key topics and technical requirements

ISO 28781 addresses the lifecycle and technical expectations for subsurface barrier valves, including:

• Functional requirements: operational characteristics, well and environmental parameters, compatibility with related well equipment and optional requirements.
• Technical specification and design criteria: materials, performance envelope, drift diameter and design documentation.
• Design verification and validation: procedures and graded validation requirements to demonstrate conformity with design intent.
• Manufacturing and supplier requirements: documentation, product identification, traceability, material records, quality controls and assembly/functional testing.
• Testing and performance: functional tests, performance envelopes, validation of shear devices and debris‑related tests (annex guidance).
• Repair, redress, handling and storage: requirements to preserve product integrity during logistics and refurbishment.

Practical applications and who uses this standard

ISO 28781 is used by professionals involved in downhole equipment selection, manufacture and quality assurance:

• Manufacturers and suppliers: to define design, validation and production controls for subsurface barrier valves.
• Operators and purchasers: to specify minimum performance, quality grades and validation levels in procurement.
• Design and QA/QC engineers: to validate materials, testing regimes, traceability and functional performance.
• Test labs and inspection bodies: to apply normative testing and verification procedures in annexes.

Typical applications include creating temporary or semi‑permanent barriers in tubing for well interventions, flow isolation during injection/production operations, and enabling safe well workovers (note: not as emergency flow‑control safety devices).

Related standards and exclusions

ISO 28781 excludes products and subject matter covered by other standards (for example ISO 17078, ISO 16070, ISO 14310, ISO 10432, ISO 10423) and explicitly excludes downhole chokes, wellhead plugs, sliding sleeves, casing‑mounted flow‑control valves, injection valves and drill‑stem test tools. It also does not cover installation, maintenance or external control systems.

Keywords: ISO 28781, subsurface barrier valves, downhole valves, petroleum industry, drilling and production equipment, design validation, functional testing, traceability, performance envelope.