ISO 19901-1:2015

Overview

ISO 19901-1:2015 - "Petroleum and natural gas industries - Specific requirements for offshore structures - Part 1: Metocean design and operating considerations" provides general requirements for determining and using meteorological and oceanographic (metocean) conditions in the design, construction and operation of offshore structures. This second edition (2015) updates the 2005 version and applies to fixed and floating platforms, mobile offshore units and other offshore infrastructure used in the petroleum and natural gas industries.

Key topics and technical requirements

ISO 19901-1:2015 defines the metocean parameters, data practices and characterization methods needed to support structural and operational decisions. Major technical topics include:

• Determination of relevant metocean parameters (extreme, long‑term statistical distributions, and normal conditions)
• Return periods and extreme/extrapolated conditions for design and assessment
• Wind, including profiles, spectra and wind‑induced actions and effects
• Waves, spectral sea states, directional spreading, wave kinematics and maximum individual wave heights
• Currents, profiles, blockage and velocity characterization
• Water levels, tides, storm surge and extreme water levels
• Other environmental factors: marine growth, tsunamis, seiches, sea ice/icebergs, snow/ice accretion
• Metocean data collection and quality control, instrumentation and reporting requirements for meteorology and oceanography
• Parameters for different activity durations: short‑term operations (e.g., lifts/installation), medium‑term activities and long‑term fatigue/operational assessments
• Regional guidance via informative annexes (Northwest Europe, West Africa, Offshore Canada, Sakhalin/Sea of Okhotsk, Caspian Sea, Southern East Asian Sea)

Practical applications - who uses this standard

ISO 19901-1:2015 is used by:

• Offshore structural and marine engineers for design load definition and fatigue assessments
• Metocean specialists and oceanographers for site resource characterization and data analysis
• Asset owners, operators and project managers for site-specific assessments, weather windows and operational limits
• Contractors and installation teams to plan fabrication, transportation and installation activities
• Regulators and certifying bodies evaluating design integrity and safety cases

Practical uses include defining limiting environmental conditions, selecting design environmental cases, determining weather windows for lifts and tow operations, and specifying data collection and QC protocols.

Related standards

• ISO 19901 series (other parts cover seismic, topsides, geotechnical, weight control, stationkeeping)
• Referenced related documents: ISO 19905‑1 (jack‑up site assessment), ISO 19906 (arctic offshore structures), ISO 19901‑3 (topside structures)

ISO 19901-1:2015 is essential for projects that require robust, consistent metocean criteria for offshore petroleum and natural gas structures, supporting safer design and more reliable operations.