Title of Powerpoint Arctic Structures Design Subhead Date of Event ©2015 American Bureau of Shipping.  All rights reserved. Title of Powerpoint Subhead Arctic Structures Design Date of Event Location of Event Name of Presenter Title of Presenter, Company

Outline ISO 19906 Gaps and Uncertainties ABS Approach for Arctic Rules and Standards Framework for design development and evaluation Design tool development I will start with a discussion about ISO 19906. Move to talking about gaps and uncertainties in 19906, knowledge and research Then we will move onto a discussion about how we can move forward.

ISO TC67/SC7 19900 Series Standards for Offshore Structures ISO 19900 – General requirements for offshore structures ISO 19901 – 1, -2, -3, -4, -5, -6, -7 specific requirements ISO 19902 Fixed Steel Offshore Structures ISO 19903 Fixed Concrete Offshore Structures ISO 19904 – 1, -2 Floating Offshore Structures ISO 19905 Mobile Offshore Units (site-specific assessment) ISO 19906 Arctic Offshore Structures Was issued on 15 December 2010 ISO has a series of standards for Offshore Structures A word on ISO standard development in contrast to ABS Rule development ISO uses committees typically populated by industry leaders, participation on a committee is voluntary. Committees need company commitment and personal commitment of individuals. This means that sometimes the industry’s best are not always present. And often the loudest voice on the committee sets the tone and agenda. This structure needs a very strong chair. ABS prepares standards based upon our understanding of industry needs. We do our own research first and then through consensus building prepare a standard (Rules, Guides or Guidelines). Rules and Guides go through internal review and then to our Rules Committee (industry members). Standards are continuously refined based on user feedback and in-service experience.

ISO 19906 International Standards Organization – Arctic Offshore Structures Published in 2010, most recent international developed standard Builds on existing Arctic codes – API RP 2N, CSA S471, SNIP, VSN Most appropriate for fixed Gravity Based Structures (GBS) Current work ongoing to develop Ice Management and Arctic Operations sections Lacks a complete set of design requirements, particularly for drilling (exploration) units Uncertainty and technology gaps lead to difficultly in utilizing the Code for design and evaluating fitness for purpose ISO 19906 Arctic Offshore Structures: The “go to “ standard for arctic offshore structures Standard proper is a recommended practice Appendix A gives additional information and guidance

Gaps: Floating Structures ISO 19906 has limited provisions for floating units Design methodologies and target reliabilities fail to differentiate between MODUs or permanent floating installations (e.g. FPSOs) Design ice load models do not consider ice management, stationkeeping compliance, disconnection, or move-off strategies Lighter ice concentrations and weaker ice properties not addressed: These are the typical design conditions for most near-term Arctic drilling interests Lack of guidance on expectations and confidence level from ice model testing

Gaps: Jackup Structures ISO 19906 does not have applicable clause – silent on jackups No design ice loads from disconnection and move-off strategies or ice management No ice load models from the pack ice condition considering the ice concentration Ridges, ice rubble build-up, compliance of jackup structure are not addressed 19906 Appendix does provide guidance on multi-legged structures Working through some of the factors reveals fairly wide variability and a substantial range in forces

Arctic Units Classed by ABS Kulluk Glomar Beaufort Sea 1 Molikpaq SSDC/MAT There is a history of successful firsts. Parker Kulluk: Conically shaped floating mobile offshore drilling unit Operating drafts = 9 to 11.5m 81.0m main deck diameter x 18.5m Position mooring system 12 points Design environmental conditions Water depth = 24 to 55m Air temperature = -50°C Wind speed = 54 knots Maximum significant wave = 4.7m Current speed = 1.4 knots Seasonal operation in Beaufort Sea from June to December Ice resistance mechanism Ice strengthened with ABS Ice class 1AA (1980 MODU Rules) it stands for “Extreme Ice Condition” i.e. 1-year ice with 1m thick. to be towed away when multi-year ice floe approaches SSDC/ MAT: Design environmental conditions Wind velocity = 106 mph Current speed = 3.7 knots Air temperature = -40°C Wave height = 12.5m/15 seconds Ice conditions 8m thick mutli-year ice floes Design ice loads 2m thick first-year landfast ice Global ice loads 8m thick multi-year ice = 460 kip/ft over 530’ (1000 MN) 2m thick multi-year ice = 150 kip/ft over 530’ (353 MN) Local ice loads 1150 kips on 2 ft2 for vertical face (27.5 MPa on 0.186 m2) 575 kips on 2 ft2 for mat sloping face(13.6 MPa on 0.186 m2) MOLIKPAQ: Original design environmental conditions Limiting ice = 8m thick Wave height = 7.3m/10 seconds Storm surge = 2.13m Extreme hourly wind = 85 mph Original design ice loads Global ice load = 640 MN (460kip/ft over 305’ or 93m) Local ice loads vary depending on surface slope and size of load patch (contact area) 6.9 MPa (on 0.4m x 1.22m area) for plating in upper ice zone (El. 0 to -9m) 2.9 MPa (on 0.4m x 1.22m area) for plating in upper transition zone (El. 0 to +2m) 4.3 MPa (on 0.4m x 1.22m area) for plating in lower ice zone (El. -9 to -21.4m) 1.1 MPa for stiffeners in upper transition zone (El. 0 to +2m) 3.5 MPa for stiffeners in upper ice zone (El. 0 to -9m) 2.1 MPa for stiffeners in lower ice zone (El. -9 to -21.4m) Ice strengthened scantlings of the hull The core of the annulus is filled with sands providing majority of the horizontal resistance Gravity from steel weights, consumables and water ballast Later was verified for operating at a site in the Beaufort Sea for 7 years Design ice load 50-year return ice condition Limiting ice increased to 10m Global ice load increased to 800 MN (580 kip/ft over 305’ or 93m) Extreme local ice load increased to 11.45 MPa over a area with 1.22m diameter.

ABS Approach: Design & Review Framework There is no one set of rules/standards that address all the design requirements of ice-capable jackups Design & Review (D&R) framework is the means to combine relevant rules and standards and research Effort currently in progress with designers ABS Approval-in-Principle Arctic offshore structures coupled with model test, numerical simulation and further full scale validation tests Jackup site-specific requirements

Rationale for a Comprehensive Framework Example: Seasonal Summer Operations Prescriptive rules and standards may miss critical design conditions Mild temperatures Less ice Low temperatures More severe ice Winter storms Drilling operations Move out, transit Ice strengthening of legs Ice floes in waves Ice strengthening of hull (jack down, wet tow) Ice accretion Framework leads to scenario based design Requires an experienced and knowledgeable team to get it right

Basis of the Framework: Leading to an AIP Strengths Gaps ABS MODU Rules Service experience Ice loads on legs Transit analysis ISO 19906 De facto industry standard Ice loads and methodology Primarily for fixed structures ISO 19905-1 Jackup site specific requirements Ice loads not addressed Transit conditions not addressed ABS AIP Applicable when specific rules and standards are lacking For transit conditions the IACS ship rules can be utilized Petroleum and Natural Gas Industries Standards ISO 19096 – Arctic Offshore Structures (2010) ISO 19905-1 – Site-specific Assessment of Mobile Offshore Units, Part-1: Jackups (2012) ABS Guidance Notes on Review and Approval of Novel Concepts

Way Forward Use the D&R framework and the agreed list of standards and methodologies based on the specified operation scenarios for the asset Evaluate load level frequency against response (both resistance capability and operations decision limitations) Use multiple load determination approaches to establish confidence (basis of sound engineering is this cross checking process) Early engagement with Class and Regulatory Agencies is an important part of the design development partnership

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