Page 235 - Introduction to Petroleum Engineering

222 UPSTREAM FACILITIES

Semi- Tension
Jack-up Fixed Compliant submersible leg Spar
platform platform tower platform platform platform

FIgURE 11.10 Examples of offshore platforms.

FIgURE 11.11 Offshore platform in dry dock, Galveston, Texas. Source: energy.fanchi.
com (2003).

depths of up to 7500 ft, and floating production offloading (FPO) vessels and subsea
completions can be used at arbitrary depths. ROV technology imposes a practical
limit on depth since ROVs may be the only way to access equipment on the seabed.
Offshore drilling has many similarities to onshore drilling. Both use rotary dril-
ling technology, and a top drive can be used on an offshore rig. The top drive rotates
the drill string and is attached to the traveling block so it can move up and down as