| 摘要 |
Apparatus for drilling for or production of oil or gas comprises a normally vertical tower 10 of length to extend above sea level, means (15) extending throughout the length of the tower 10 to receive a drilling mechanism therein, and at least an upper and a lower thruster unit 22, 24 located externally of the tower 10 and adjustable in position along the length thereof, said thruster units being operable to effect dynamic positioning of the tower. <IMAGE> |
