ISO 13628-4:2010

Overview

ISO 13628-4:2010 - "Petroleum and natural gas industries - Design and operation of subsea production systems - Part 4: Subsea wellhead and tree equipment" provides specifications for the design, manufacture, testing, marking, storage and shipping of subsea wellheads, mudline wellheads, drill-through mudline wellheads, and both vertical and horizontal subsea trees. The standard covers individual sub‑assemblies and complete subsea tree assemblies, associated tooling for handling, testing and installation, and identifies critical components with prescriptive requirements. It is intended for worldwide use and is written to be auditable; users remain responsible for meeting any additional national or jurisdictional regulations.

Key topics and technical requirements

• Equipment scope and definitions: Detailed listing and definitions of subsea trees, tree connectors, tubing hangers, valves, chokes, actuators, tree caps, guide frames, running tools, and control interfaces.
• Design and performance: Functional and mechanical design requirements for subsea wellhead and tree systems, including service condition considerations and product specification levels.
• Materials and welding: Material selection criteria and welding quality requirements tailored to subsea service environments.
• Quality control and testing: Factory acceptance testing (FAT), inspection, marking, storing and shipping requirements to ensure traceability and fit‑for‑service delivery.
• Tooling and interfaces: Specifications for tree running tools, cap running tools, flowline/umbilical connectors, re‑entry interfaces and other installation/retrieval tooling.
• Specific assemblies: Requirements for mudline suspension systems, tubing hanger systems, drill‑through mudline equipment, and miscellaneous end‑connectors (flanged, clamp, threaded).
• Exclusions: Explicit out‑of‑scope items such as subsea control pods, installation/workover risers, subsea manifolding and jumpers, subsea process equipment, and repair/rework of used equipment.

Practical applications

• Use ISO 13628-4:2010 to develop technical specifications, procurement documents and inspection plans for subsea wellhead and tree equipment.
• Apply the standard during design reviews, vendor qualification, factory acceptance testing and pre‑installation verification to reduce operational risk.
• Reference the standard for auditable compliance in engineering, manufacturing and quality assurance processes for subsea completions and satellite/cluster well applications.

Who should use this standard

• Subsea production and completion engineers
• Equipment manufacturers and fabricators (trees, wellheads, tubing hangers)
• Project and procurement teams preparing technical specifications and tenders
• Quality, inspection and test engineers conducting FATs and QA audits
• Asset owners/operators planning installation and lifecycle management of subsea wells

Related standards

• ISO 13628 series (Parts 1–3, 5–11 listed in the document) for complementary subsea production system requirements and interfaces.
• Note: ISO 13628-4:2010 aligns with industry practice and may be used alongside equivalent API documents where applicable.

Keywords: ISO 13628-4:2010, subsea wellhead, subsea tree, tubing hanger, mudline wellhead, subsea production systems, factory acceptance testing, subsea equipment design, quality control, subsea completion.