ISO 20312:2011

Overview

ISO 20312:2011 - Petroleum and natural gas industries - Design and operating limits of drill strings with aluminium alloy components - sets out the design principles and operating limits for drill strings that contain aluminium alloy drill pipe (ADP) manufactured in accordance with ISO 15546. The standard provides definitions, symbols, mechanical and dimensional property requirements, and practical calculation methods (formulas and figures) to support safe and effective use of aluminium alloy components in drilling operations. Data are expressed in SI units.

Key topics and requirements

• Scope and applicability: Applies specifically to drill strings containing aluminium alloy pipes made per ISO 15546.
• Terms, symbols and definitions: Comprehensive glossary covering ADP, tool joints, buckling modes (sinusoidal/helical), dogleg severity, and other drilling terms.
• Mechanical and dimensional properties: References ISO 15546 for pipe and tool-joint properties; includes buoyant weight, modulus, yield strength and other essential parameters.
• Design considerations: Guidance on assembly design, temperature effects on material selection, hydroabrasive and corrosive resistance, buckling behavior and stability limits.
• Calculation methods: Normative calculations (Annex B) and informative examples to determine collapse, buckling loads, effective axial forces, and combined load capacity.
• Operation and fatigue: Operating recommendations, fatigue strength limitations and combined-load capacity limitations for aluminium-containing drill strings.
• Inspection and classification: Wear-based inspection procedures, marking and classification of aluminium drill pipe and tool joints, plus repair and discard criteria.
• Logistics: Requirements for transportation and storage of aluminium drill pipe.
• Supplementary material: Annex A (technical properties of integral tool-joint and heavy-wall ADP) and Annex C (SI–USC conversions).

Note: The standard uses prescriptive language - “shall”, “should”, and “may” - to indicate mandatory, recommended, and optional provisions.

Practical applications and users

ISO 20312:2011 is intended for professionals and organizations involved in drilling operations and equipment lifecycle management:

• Drilling and completion engineers selecting and designing drill strings with aluminium alloy components
• Manufacturers of aluminium alloy drill pipe and steel tool joints ensuring conformity with ISO 15546 and ISO 20312
• Operations managers and rig crews implementing operating limits, torque/make-up and inspection regimes
• NDT/inspection personnel and quality assurance teams (references ISO 9712, ASNT guidance)
• Procurement, maintenance and safety teams assessing repair, classification, transport and storage requirements

Using ISO 20312 helps reduce risk from buckling, fatigue and corrosive/hydroabrasive damage, improve operational efficiency through weight savings and buoyancy calculations, and ensure consistent inspection and classification practices.

Related standards

• ISO 15546 - Aluminium alloy drill pipe (normative reference)
• ISO 9712 - Non-destructive testing - Qualification and certification of personnel
• ASNT SNT-TC-1A - Personnel qualification and certification in NDT (recommended practice)

Keywords: ISO 20312:2011, aluminium drill pipe, ADP, drill string design, ISO 15546, drilling fatigue, buckling, tool joints, drill pipe inspection.