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www.sname.org/sname/mt January 2013 OUTLINE SPECIFICATIONS FOR CATEGORY D RIG LIGHTSHIP WEIGHT29,000 MT DISPLACEMENT 51,000 MT VARIABLE DECK LOAD IN OPERATION 4,000 to 5,000 MT VARIABLE DECK LOAD IN TRANSIT 3,000 MT WATER DEPTH 100 to 500 m DRILLING DEPTH 8,500 m POWER GENERATION 6 x 5 MW = 30 MW THRUSTERS6 x 4 MW = 24 MW MOORING SYSTEM 8/12 lines, 84 mm chain, 15 metric ton anchors POSITIONING SYSTEM POSMOOR ATA + DP 3 (Bf7) DRAFT SURVIVAL 19.5 m DRAFT OPERATING 23.15 m MAX DRAFT OPERATING 25.15 m DRAFT TRANSIT 9.45 m AIR GAP IN SURVIVAL 16.60 m ACCOMMODATION 130 persons in single cabins CRANES2 lattice boom rig cranes, 45 m out- reach, with 65 tons external capacity at 15 outreach; 35t knuckle boom stacking crane aft CLASSIFICATION DNV 1A1 Column Stabilized Drill- ing unit (N), Drill (N) HELDK CRANE POSMOOR ATA CLEAN DESIGN DYNPOS AUTRO and ER drilling contractor was given a long-term contract to build and operate the unit on our behalf. e category D is a workhorse rig for production drilling, focusing on completion and interven- tion needs with optimized ushed deck space for equipment placement for safe operations. Its main features include: ? a GVA 4000 NCS concept based on proven design; only eld proven technology and equipment are used in the design ? excellent motion characteristics ? subsea skidding deck ush with cellar deck ? workover skidding decks ush with drilloor ? separate drilling and completion uid system ? 1.5 derrick, with simultaneous drilling and building stands ? 1.5 moonpool trip saver, hanging o blow out pre- venter (BOP) and riser in the moonpool while running Christmas tree valve arrangement ? enclosed pipe deck area ? independent handling of BOP and Christmas trees ? protected working and storage areas ? low emissions to the environment ? preparation for full winterization on NCS ? preparation for all Statoils subsea system on the NCS ? BOP, riser tension, and compensation systems designed for existing well head templates with focus on well head fatigue life ? preparation for deep water (7,500 ft. or 2,200 m) and sub-arctic operations (can be implemented by minor post upgrades). Marine issues Working with the category D rigs has been interest- ing from a naval architecture point of view. Layout of the topsides was given high focus in the design phase. Ample deck space, wind protection of critical areas, and logistics in operation are key to opera- tional eciency. However, the rather high windage area of the topsides led to a situation in which the wind overturning moment became the limiting fac- tor for stability calculations in accordance with the rules of the Norwegian Maritime Authority (NMA). In contrast, for many rigs in operation it is actually the intact stability requirement of metacentric height = 1 m in operation that is the limiting stability criteria. To secure robustness in design and reserves for future use, the actual limiting stability criteria is not regu- latory, but a Statoil-imposed demand of metacentric height of at least 2 m at survival draft. In addition to A category D drillrig, with full winterization package.