Page 125 - Drilling Technology in Nontechnical Language

116 Drilling Technology in Nontechnical Language Second Edition

A large semisubmersible rig may be capable of carrying most or all
of the equipment and supplies needed for drilling an entire well. If an
exploration well were required in a remote area, this would be a serious
advantage, as the rig could pick up supplies at a suitable place and proceed
to the well location without requiring supply boats being mobilized over
large distances.

Fig. 5–6. Semisubmersible rigs offshore Ghana

Accommodation for all personnel is available on the rig. There will
also be catering and some leisure facilities, such as a gym, cinema, library,
and satellite TVs in the bedrooms. Many of the crews and supervisors will
work on a rotation of 28 days on board followed by 28 days off.

Semisubmersible rigs may be self-propelled or they may have to be
towed by tugs between locations. On location, they might be anchored in
place, but they can also be dynamically positioned, as explained later.

_Devereux_Book.indb 116 1/16/12 2:08 PM