How do semi-submersible rigs work?

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.

How are offshore rigs powered?

The energy needed on offshore drilling rigs is usually supplied by diesel engines. Typically these engines use 20–30 m3 diesel fuel per day, depending on the operations performed. Several measures can be used to reduce energy consumption, the amount of diesel burned, and emissions to the air.

How do offshore oil rigs stay in place?

The platforms can be kept in place through large, heavy anchors, or through the dynamic positioning system used by drill ships. With a floating production system, the wellhead is actually attached to the seafloor once the drilling is completed, rather than being attached up to the platform.

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.

How is a semi-submersible rig kept above the hole at a drill site?

A more popular design for semisubmersible rigs is the column-stabilized semisub. Here, two horizontal hulls are connected via cylindrical or rectangular columns to the drilling deck above the water. Mooring lines anchor the rig above the well, and dynamic positioning can help to keep the semisub on location, as well.

How much electricity does an oil rig use?

Offshore oil and gas platforms use 16 terawatt-hours a year to power their operations. This is an opportunity for wind and solar.

How does an oil rig float?

Simple physics. As with oil tankers, heavy load barges and cruise ships, deep sea oil rigs float according to basic physics. As the weight of the rig pushes downwards displaced water pushes upwards, thus keeping the structure afloat.