Overview
ISO 13679:2019 - "Petroleum and natural gas industries - Procedures for testing casing and tubing connections" - specifies standardized tests to evaluate the galling tendency, sealing performance, and structural integrity of casing and tubing connections used in oil and gas wells. This second edition (2019) updates the earlier 2002 version and supplements API RP 5C5:2017, aligning connection qualification with contemporary test methods and adding clarifications for manufacturers and test laboratories.
Key topics and requirements
- Test scope and limits: Defines tests for the most commonly encountered well conditions; explicitly excludes some scenarios (for example, effects of corrosive fluids are not considered).
- Supplement to API RP 5C5:2017: ISO 13679:2019 replaces or augments specific clauses in API RP 5C5 where noted and requires manufacturers to provide a test plan and detailed connection data.
- Nominal connection performance envelope: Manufacturers must supply a connection specification sheet and datasheet that state the intended assessment level and uni-axial ratings for the connection.
- Specimen geometries and assessment levels: New specimen geometries (e.g., XH-XL) and revised Connection Assessment Level(s) testing sequences are included.
- Anisotropic reference curves: Recognizes non-isotropic material behavior in OCTG; recommends development and reporting of anisotropic yield curves (e.g., using Hill’s criterion) in place of isotropic VME curves where appropriate.
- Near-yield loading effects: Requires awareness and monitoring of cyclic plastic strain accumulation under near-yield cyclic loading; manufacturers should recommend monitoring locations and acceptable plastic strain levels.
- Test reporting: Test reports must reference ISO 13679:2019, include temperature and DLS used, and document the test plan, make-up parameters, and repair procedures.
Applications and users
- Who uses it: Connection manufacturers, well completion and drilling engineers, materials and testing laboratories, qualification teams, and operators specifying or accepting tubular connections.
- Practical uses:
- Qualification and validation of casing/tubing connection designs before field deployment.
- Producing standardized test reports for procurement and regulatory compliance.
- Evaluating connection behavior under complex loading (axial, pressure, bending, torsion).
- Informing design decisions where anisotropic pipe body behavior or near-yield effects may influence performance.
Related standards and references
- API RP 5C5:2017 (primary recommended practice supplemented by ISO 13679:2019)
- ISO 11960 - Steel pipes for use as casing or tubing for wells
- ISO 3183 - Steel pipe for pipeline transportation systems
Keywords: ISO 13679:2019, casing and tubing connections testing, API RP 5C5, near-yield loading, anisotropic yield curves, connection performance envelope, OCTG, galling, sealing performance, structural integrity.