Unmanned platforms need multifunctional control

The North Sea is not for the faint-hearted. It is well known that working as a diver on gas and oil wells there is one of the most dangerous of all occupations. While the designers of control systems for unmanned platforms and subsea wells may not have to face the same physical dangers, they have a challenging task all the same. Frequently, these control systems must handle a mix of signals and substances that they will rarely encounter in other applications. One such application is a recent project by Phillips Petroleum Company United Kingdom Limited, in which an unmanned platform acts as a control station for subsea wellhead control modules (SCMs) attached to gas wells in the North Sea. The unmanned platform, called Audrey B, has to regulate the supply of gas from two wells, which are some 18km away at a site called the Ann subsea development. To do this, Audrey B has not only to handle electrical control signals, but also to supply electrical power and hydraulic power to the SCMs. In addition, the control system regulates the supply of methanol to the subsea wells, conducted via an umbilical.<>