MG Hulme Semi-Submersible Rig

Ballast Control and Tank Gauging

When Monitor Systems designed, installed and commissioned its new ballast control and tank gauging system on Transocean's MG Hulme rig, it was to replace out of date equipment difficult to maintain because of unavailable spare parts, whilst at the same time upgrading operational system reliability and performance.

Using a more compact steel control console, valuable space savings were achieved in the control room allowing for a new fire and gas panel to be installed. Whilst replicating existing control functions, benefits of the new failsafe system included new operator control graphics in an improved ergonomic layout with a host of valuable operator alarms not present in existing system monitoring tank levels, valve open and close feedback, valve operating times and pump protection via pressure alarms.

The operating control and data management system is driven by a Siemens Redundant PLC and distributed I/O controlling valves, pumps and monitoring tanks holding ballast; diesel oil; potable water; drill water; salt water; contaminated drain, bilge and other fluids. Ballast control functions are presented graphically to the operator providing an easy interface between operator and equipment. Tank levels are shown both graphically and numerically, whilst audio-visual alarms are displayed in an alarm banner shown on selected screens and a separate alarm page.

This high availability system is powered by an uninterruptible supply (UPS) fed by both mains and emergency power. It also has sufficient battery capacity to run the system for 30 minutes without any power input.

The system can be supplied in its entirety or installed to utilise client's existing valves, actuators and tank sensing installations.