Installation of sub-sea modules
Installation of subsea modules has becoming a major issue in engineering of subsea platforms. As the world offshore oil and gas production moves to deeper fields, the need for more efficient and more economical deployment methodologies increases.
During installation, the horizontal position of the vessel is kept by a dynamic positioning system. State of the art offshore cranes have an Active Heave Compensation system to control the motion of cargo throughout the splashing zone.
In best case scenarios, vertical rotation control is done by tag lines or more than one crane. In other scenarios, vertical rotation has reduced control or no control at all.
The lowering operation is assisted by an ROV, which follows until the module reaches the sea bed. Positioning of subsea modules on the sea bed is ensured by running tools and ROV’s. It is visually controlled by ROV cameras.
Accurate positioning of the modules highly depends on the stability of the vessel which in turn depends on the weather conditions.