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The types of mobile offshore drilling units (MODUs) used for offshore drilling has evolved over time.
Types of offshore drilling units currently in use
One may ask why there are so many types, sizes, and capabilities of offshore units. The answer involves different technical, economic, government, and safety requirements to accomplish a specific drilling program. No one type can satisfy all the requirements for every drilling location; thus, we have to understand all types to make a correct decision on their use. The major types of units are:
- Fixed-platform rigs
- Tender assist drilling (TAD)
- Conventional ship-and barge-shaped rigs
- Ultradeepwater units