GENERAL DESCRIPTION
M-531 is a Marathon LeTourneau Hull 56 class self-elevating jack-up drilling unit, originally built for offshore shelf drilling and later upgraded for cantilever operations. Designed for robust shallow-to-mid-water operations, the rig has a long operational history under multiple operators (ex-Noble Leonard Jones, Coral Sea, Penrod 62) and was later operated by Paragon Offshore.
The rig features three lattice legs with large spud cans, a skidable cantilever drilling package, and proven rack-and-pinion jacking technology, making it suitable for development drilling, work-overs, and platform-adjacent wells.
CLASSIFICATION & REGULATORY
• Rig Name: Paragon M-531
• Rig Type: Self-Elevating Mobile Offshore Drilling Unit (MODU)
• Hull Design: Marathon LeTourneau – Hull 56
• Builder: Marathon LeTourneau, Vicksburg, Mississippi, USA
• Year Built: 1970s (cantilever conversion later under ABS)
• Owner (2014): Paragon Offshore Leasing (Luxembourg) S.A.R.L.
• Flag: Panama / Liberia (historical)
• Class: ABS ✠A1 Self-Elevating Drilling Unit
• IMO No.: 8753562
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OPERATING CAPABILITIES
• Maximum Water Depth: ~300 ft class
• Maximum Drilling Depth: ~25,000 ft
• Operating Modes:
• Afloat / Transit
• Preload
• Elevated Drilling
• Elevated Survival
• Wind Limits:
• Drilling: up to 70 knots
• Survival / Transit: up to 100 knots (mode-dependent)
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PRINCIPAL DIMENSIONS
• Length Overall: 247.15 ft
• Length (Load Line): 237.26 ft
• Breadth: 200.50 ft
• Breadth incl. Helideck: 226.00 ft
• Hull Depth: 26.00 ft
• Gross Tonnage: 6,533 GT
Legs & Spud Cans
• Number of Legs: 3
• Leg Length: 500.6 ft (310 ft for ocean tow)
• Spud Can Diameter: 46.0 ft
• Spud Can Area: 1,585 ft² each
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JACKING & STRUCTURAL SYSTEMSJACKING & STRUCTURAL SYSTEMS
• Jacking Type: Electro-mechanical rack & pinion
• Designer / OEM: LeTourneau
• Pinions: 4 per chord, 12 per leg
• Jacking Speed: ~1.5 ft/min
• Max Jacking Load: 16,250 kips
• Max Holding Capacity: 28,800 kips
This system provides high redundancy, controlled preload capability, and proven storm survivability.
CANTILEVER & DRILLING ENVELOPE
• Cantilever Beam Length: 123 ft
• Maximum Aft Reach: ~68 ft beyond transom
• Substructure Skid (Longitudinal): 19 ft
• Drill Floor Skid (Transverse): ±15 ft
• Hook Load: 1,300 kips
• Setback Load: 500 kips
• Max Combined Drilling Load: 1,500 kips
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DRILLING PACKAGE (SUMMARY)
• Derrick: Dreco beam-leg derrick, 160 ft
• Drawworks: National 1625, 2 × 1,000 HP DC motors
• Top Drive: Varco TDS-4S (650-ton)
• Rotary Table: National C-375
• Mud Pumps:
• (3) National 12-P-160, 1,600 HP class
• BOP Stack:
• 13-5/8” 10,000 psi ram + annular
• Full choke, kill, diverter & Koomey control system
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CRANES & AVIATION
• Cranes:
• (3) Marathon PCM-120 pedestal cranes
• 100-ft and 125-ft booms
• Helideck:
• 70-ft diameter
• Rated for Sikorsky S-61 (20,500 lb)
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POWER GENERATION
• Main Power:
• (3) EMD 16-645-E8 generators
• ~1,400 kW each
• Emergency Generator:
• CAT diesel, 400 kW
• Electrical System:
• 600 VAC / 60 Hz SCR distribution
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STORAGE & CAPACITIES (SELECTED)
• Fuel Oil: ~6,003 bbl
• Drill Water: ~4,646 bbl
• Potable Water: ~827 bbl
• Preload Capacity: ~36,985 bbl
• Mud Pits: ~1,480 bbl
• Bulk Mud / Cement: Multi-tank pressure systems
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ACCOMMODATION & SAFETY
• POB: ~90–100 persons
• Lifeboats:
• (2) 65-person enclosed boats
• (2) 28-person survival capsules
• Firefighting:
• Dual fire pumps, fixed CO₂ systems
• Compliance: IMO MODU Code, ABS, Flag State
