Watch: How do Offshore Oil Platforms Function?

Do you know how massive offshore oil rigs float and extract oil from beneath the seabed?

Offshore Oil rigs or platforms are structures constructed for oil drilling and extraction. An oil rig is buoyant and can float like a ship.

The oil rigs have large mono-hulls and are fully equipped with processing facilities. Incredibly, oil rigs can stay afloat in one place for a prolonged time. Some oil rigs are fully functional, but some can store extracted oil and gas. 

In deep waters, up to 1700 feet, fixed platforms with large steel or concrete legs are used. These legs attach to the ocean floor, providing stability. 

For depths from 1500 to 4900 feet, compliant towers are used, offering a taller fixed platform.

Now, we have floating oil rigs for deeper waters, up to 12,000 feet. There are various types, but today, let’s focus on the semi-submersible platform as an example.

This platform is like a giant buoy supported on large pontoons, giving it buoyancy to float and be towed from one location to another. Some even have thrusters for added mobility.

The pontoons are slowly flooded, keeping them below sea level. This ensures the work decks stay afloat while maintaining stability during rough seas.

A lot goes into stabilizing the rigs to stay afloat on the water. Some drilling companies hook up the rigs to a stabilizing anchor using wire ropes. 

In other instances, they use computer-coordinated thrusters to keep the oil rigs stable. They may also build a series of propellers to add stability. However, stabilizing the rigs needs sophisticated tools.

Now, let’s explore what’s on an oil rig.

We’ve got the hoisting system for drilling, cranes for transporting supplies, living quarters for the crew, a helicopter pad for transport, and emergency lifeboats for safety.

The main purpose of an oil rig is to drill and extract oil from below the seabed. The hoisting system lowers the drill string, and a casing is used to reach the layers of rock where the oil lies.

As drilling gets closer to the oil, a crucial device called a blowout preventer is installed to avoid catastrophic events caused by high-pressure oil. It’s like the rig’s emergency brake to prevent oil spills. 

Once oil is successfully extracted, it’s pumped into pipelines and delivered to onshore facilities. Subsea pipelines, like the vast network in the Gulf of Mexico, play a crucial role in this process. 

Each drilling system is designed to withstand a wide range of wind and wave forces, including severe winter storms and hurricanes. 

We hope that you have now understood how these mega rigs float and extract oil from the sea bed. 

Watch this video to know more-

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Zahra is an alumna of Miranda House, University of Delhi. She is an avid writer, possessing immaculate research and editing skills. Author of several academic papers, she has also worked as a freelance writer, producing many technical, creative and marketing pieces. A true aesthete at heart, she loves books a little more than anything else.

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