Page 15 - Offshore Well Construction

CHAPTER 11
Rig Equipment and Sizing
Petroleum Extension-The University of Texas at Austin

GENERATIONS OF OFFSHORE DRILLING UNITS
Generations are used to differentiate semisubmersible hulls. This section describes the term Generations.

Year of Construction
Generation is traditionally based on age. Semisubmersibles are built to satisfy demand and construction dates coincide
with peaks in oil price and increased demand. Generations are based on the following construction dates.

Generations Year of Construction

1st 1962 to 1969
2nd 1970 to 1981
3rd 1982 to 1986
4th 1987 to 1998
5th 1999 onwards (?)

Technical Capability
Generation is based on the technology of equipment installed on the rig. When rigs are built, they generally reflect the
technology available at the time. As technology develops, more complex work can be carried out and, over the past
thirty years, semisubmersibles have moved into deeper water to drill deeper more complex wells.

Generations Examples of Development of Technology

1st 800 ft water depth, 2 × 1,250 hp mud pumps, kelly,
1,450 ton variable deck load (VDL), manual derrick

2nd 1,500 ft water depth, 2 × 1,600 hp mud pumps, kelly,
3,000 ton VDL, manual derrick

3rd 2,500 ft water depth, 2 × 1,600 hp mud pumps, kelly,
3,800 ton VDL, automatic pipe handling

4th 3,500 ft water depth, 3 × 1,600 hp mud pumps,
TDS3 top drive, 4,300 ton VDL, automatic pipe handling

5th 8,000 ft water depth, 5 × 2,200 hp mud pumps,
TDS8 top drive, 5,000 ton VDL, dual activity

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