Definition - What does Semisubmersible mean?
A Semisubmersible, also known as a semi-submerged ship, is a special type of marine vessel used for various purposes such as drilling operations in offshore sites for oil and gas production, safety vessels and heavy lift cranes. Generally this rig floats on water but when the drilling has to be carried out, it is submerged to the required depth.
Petropedia explains Semisubmersible
A Semisubmersible is a special type of an offshore drilling rig that floats during drilling and is supported by large pontoons submerged in water. The deck is connected and supported by large diameter buoyant columns at the corners and small intermediate columns that are connected to the pontoons. Most Semisubmersibles are not self propelled and hence have to be towed. Anchored or moored Semisubmersibles can drill in water up to 1500 meters while dynamic positioning Semisubmersibles can drill beyond 6000 meters.
Semisubmersibles are used in the following offshore applications:
- MODU (Mobile offshore drilling units)
- SSCV (Semisubmersible crane vessels)
- OSV (Offshore support vessels)
- Offshore production platforms