How does a semi-submersible oil rig work?
Semi-submersible rigs are buoyant and, unlike jack-up rigs which rest on the seabed, float during drilling operations. A semi-submersible rig is a drilling rig that is situated on a deck space that rests on several columns which, in turn, are attached to floating pontoons.
How do semi-submersible rigs float?
A semi-submersible obtains most of its buoyancy from ballasted, watertight pontoons located below the ocean surface and wave action. Structural columns connect the pontoons and operating deck.
How is a semi-submersible rig kept above the hole at a drill site?
Mooring lines anchor the rig above the well, and dynamic positioning can help to keep the semisub on location, as well. Semisubmersibles and other mobile offshore facilities are moored in systematic ways, but there are many different designs for various situations.
Do oil rig workers sleep on the rig?
Oil rigs are close-knit communities and you can expect to share your room with several other engineers, although some oil rigs do offer private rooms. Showers and toilets tend to be shared among a couple of cabins, but most bedrooms do offer a washbasin, and a television.
Do oil rigs float?
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.
Are oil rigs fixed to the seabed?
Most commonly, oil platforms engage in activities on the continental shelf, though they can also be used in lakes, inshore waters, and inland seas. Depending on the circumstances, the platform may be fixed to the ocean floor, consist of an artificial island, or float.
How do oil platforms stay in place?
They are generally anchored by combinations of chain, wire rope or polyester rope, or both, during drilling and/or production operations, though they can also be kept in place by the use of dynamic positioning.
Can oil rig workers use cell phones?
An offshore worker cannot use a cell phone aboard an oil rig or platform in these situations: Outside of the living quarters. Due to the risk of flammable gas coming up the oil well, the use of cell phones is strictly prohibited anywhere outside of the living quarters.
What is a semisub drilling rig?
What is a semisub drilling rig? A semi-submersible drilling rig or a semisub is a type of floating drilling rig that is partly submerged to provide station keeping and stability. It comprises a submerged hull typically pontoon-type columns joint together with the drilling platform by large tubulars.
What are the different types of semisubmersibles used in offshore drilling?
Based on the way the rig is submerged in the water, there are two main types of semisubmersibles: bottle-type semisubs and column-stabilized semisubs. Bottle-type semisubs consist of bottle-shaped hulls below the drilling deck that can be submerged by filling the hulls with water.
How does a semi-submerged oil rig stay in place?
But, as time progressed, naval architects realized that the rig would maintain its stabilization if the bottles were only partially submerged, but be able to drill in deeper waters. Mooring lines are then used to keep the semisub in place, and these anchors are the only connection the rig has with the sea floor.
How are production semis used in oil drilling?
When oil wells are drilled and completed by drilling vessels, production semis are towed to the field and hooked up to their permanent mooring systems. Sometimes, production semis are intentionally designed with a built-in drilling rig so that development drilling can continue on the same platform after production has started (first oil).