What are semi-submersibles?
Semi-submersibles are the choice for drilling from a floating position, due to the deep water depths. Semi-submersible (“semi”) rigs float like a ship while being towed into position, where their pontoons can then be flooded, partially submerging the rig.
Why is it called a semisubmersible rig?
Definition: “Semisubmersible” or “Semisub-” is referring to Offshore drilling rigs so called because they are combining the advantages of submersible rigs with the ability to drill in Semisubmersible drilling rig. Instead, the rig is partially submerged, but still floats above the drill site.
What does a jack up barge do?
A jackup rig is a barge fitted with long support legs that can be raised or lowered. Then “preloading” takes place, where the weight of the barge and additional ballast water are used to drive the legs securely into the sea bottom so they will not penetrate further while operations are carried out.
How much does a drillship cost?
The drillship duo had been expected to cost $1,08 billion when it was ordered in 2014, then in the Annual Report for 2019, Transocean said the cost would be around $2,07 billion in total – $925M for the then uncontracted Atlas, and $1,15B for the Titan.
What is special with a jack-up rig?
Jack-up rigs are mobile, self-elevating drilling and workover platforms equipped with legs that can be lowered to the ocean floor until a foundation is established to support the hull, which contains the drilling and/or workover equipment, jacking system, crew quarters, loading and unloading facilities, storage areas …
How are semi submersibles supposed to look like?
The next generation semi-submersibles typically appear to be a square with four columns and the box- or cylinder-shaped pontoons connecting the columns. The box-shaped pontoons are often streamlined eliminating sharp corners for better station-keeping.
What kind of vessel is a semisubmersible platform?
A semisubmersible platform is also known as semisubmersible, semisub, or semi. It is a specialized vessel designed for offshore drilling, oil production, heavy lifting, accommodation, or a combination of these functions.
What are the different types of semi submersible drilling units?
Semi-Submersible Drilling Units (SSDU) Based on the way the rig is submerged in the water, there are two main types • Bottle-type semi-subs and • Column-stabilized semi-subs 6. Bottle-type semi-subs • Hull below the drilling deck is Bottle-shaped.
How is a semisubmersible rig different from a submersible rig?
Semisubmersible rigs are the most common type of offshore drilling rigs, combining the advantages of submersible rigs with the ability to drill in deep water. A semisubmersible rig works on the same principle as a submersible rig: through the inflating and deflating of its lower hull.