Offshore Drilling Rigs 62 National Oilwell provides Drilling Modules for all offshore applications including drillships, semi-submersibles, caisson structures, barges, jackups and fixed platforms. Derricks and masts are available for applications with top drives and guide rails to resist wind loads. Our Dreco line of derricks and masts, as well as complete rigs can be furnished to meet requirements of regulatory groups including ABS, DNV, Lloyds and the Dutch Staatstoezicht. Material traceability, data books, quality assurance programs, etc. are available to meet the most stringent requirements. National Oilwell engineers are familiar with special design requirements imposed by automatic pipe and subsea B.O.P. handling systems, motion compensating devices and riser tensioning systems. These engineers have developed a variety of rig mechanization components and systems, such as complete rig skidding that facilitates movement from a centrally located remote control station.  These components are integrated in the complete drilling module to minimize weight while improving operator safety. Packages utilize a modular design concept that allows assembly using the platform cranes which substantially reduces the risk and cost during installation.  The modular concept can also be designed to facilitate a one-piece single lift of the assembled modules onto the platform in the event a heavy lift crane is available. Phillips Ekofisk Rig installation on platform. Atwood Tender Assist – Malaysia Hibernia Management and Development Company Ltd.