The largest oil rigs and how they work
Oil rigs and oil platforms are engineering mammoths designed to extract oil from under the sea and store it. They are an essential part of the global economy. They harvest crude oil and natural gases that are essential for economic stability, as well as helping to meet global demand for oils and gases.
The six largest oil rigs in the world
Sometimes, bigger is better. Larger oil rigs have enhanced stability and structural integrity, so they perform better in challenging conditions such as deep and rough waters. This means oil reserves can be mined even when the geography isn’t ideal.
Larger oil rigs can also safely store more of the collected material. They are harder to engineer and build, but the benefits are worth it. Listed below are some of the world’s largest oil drilling facilities.
Pacific Berkut (Russian coastline)
The world’s largest oil and gas platform is the Berkut oil rig. At 486 feet, it isn’t the tallest platform in the world, but it has a tremendous volume and capacity. It weighs around 200,000 tonnes and is estimated to extract 4.5 million tonnes annually.
Located in an arctic zone, the Berkut rig has been designed to withstand waves as high as 19m, high-magnitude earthquakes and collisions with ice caps up to 2m thick. Equipped with a security system, processing unit, helipad, and emergency equipment, the rig runs on four gas turbines and three generators, allowing the rig to perform at maximum efficiency.
Petronius (Gulf of Mexico)
Petronius is a deepwater-compliant tower that operates in the Gulf of Mexico. Built between 1997 and 2000, Petronius drills at depths of approximately 1,754 feet and has a measured height of 1,870 feet, making it the tallest oil platform in the world.
The facility is estimated to extract 60,000 barrels and 3,100,000 m3 of oil and natural gas daily.
Perdido (Gulf of Mexico)
The Perdido oil rig has the world’s deepest spar (the large vertical cylinder the rig is built on top of) and the second-deepest oil and gas production hub. It officially started production in 2010 and is moored in approximately 8,000 feet of water in the Gulf of Mexico.
The capacity of Perido is 100,000 barrels of oil per day.
Hibernia platform (North Atlantic Ocean)
The Hibernia oil platform was constructed to exploit the oil reserves of Hibernia, one of the oldest reserves in the world.
Producing over 1,400 barrels of oil per day, this rig sits in some of the world’s harshest weather conditions. The design of the structure reflects it; a surrounding steel structure protects the central 106m cement caisson by stopping any approaching icebergs.
Olympus oil platform (Gulf of Mexico)
Olympus, or “Mars B” oil platform (built next to the older Mars platform) is a rig designed to exploit the Mars oil field in the Gulf of Mexico. With planned expansions, the Olympus platform has a combined capacity of 48 wells and more than 100,000 barrels per day.
The exploitation of this oil field is planned to carry on until 2050, with the hopes of further expansion where possible.
Gullfaks C (North Sea)
Located in the North Sea, the Gullfaks A, B and C rigs were built to extract oil from the Vigdis, Visund, Snorre, and Tordis oil fields respectively.
On October 7, 1994, Gullfaks C set a production record with 605,965 barrels of oil produced in one day. The main Gullfaks platform has a total height measuring approximately 262 m.
Types of oil rigs
Oil rigs are structures used to extract petroleum and natural gases from beneath the seabed. There are five different types of oil rigs designed for different water depths and conditions.
- Barge rigs
- Submersible rigs
- Jack-up rigs
- Platform rigs
- Floating rigs
Barge rigs are designed for water depths of less than 20 feet. These rigs create a stable drilling environment by resting the hull on the ocean floor, creating a platform.
Submersible rigs can be used in waters 50-70 feet or less where a barge rig is not an option. These rigs submerge columns into the water that rest on the seabed to support the drilling operation.
Jack-up rigs get their name due to their ability to self-elevate from the sea floor. These rigs operate in waters of 400 feet or less.
There are two types of jack-up rigs:
- Cantilever rig, where the drilling derrick is mounted on an extendable arm.
- Keyway/slot rig, where the drilling unit is operated through an opening.
Platform rigs are anchored platforms fixed to the sea bed by a steel framework. Two different types of platform rigs are designed to drill at different depths.
- Fixed platform rigs are implemented with the intent of being a permanent structure. These rigs are typically made from steel or cement and are mostly found on the continental shelf, in water approximately 1,700 feet deep. These platforms have a drill radius of around 5 miles.
- Compliant towers are used when the desired mining area is approximately 1,500 to 4,900 feet deep. These tall, narrow towers are usually made from steel or concrete and are designed to move with the wind and waves. These rigs are technically floating platforms, though they are attached to the seabed by cables and anchors.
Floating rigs are used where it is not feasible to anchor an offshore platform due to the depth of the water. These rigs are kept in place over their intended target using techniques like dynamic positioning and anchoring systems. There are multiple types of floating rigs in use globally.
- Semi-submersible platforms float on top of the water, with the majority of the overall facility mass contained below the water level to stabilise the platform. This type of stabilisation allows them to safely drill at waters of 3000 to 10,000 feet.
- Drill ships are typically used for the exploration, drilling and capping of wells. The equipment used for drilling is fixed directly onto the deck of the vessel and is utilised through a “moon pool”, an opening located in the centre of the ship.
How heat exchangers are used in large oil rigs
On an oil rig, machinery operates under demanding conditions and produces significant amounts of heat. Heat exchangers, an essential part of the cooling system, dissipate heat to prevent damage or inefficiencies.
Below are some of the most critical places where heat exchangers are used on oil rigs. If you engineer oil rigs and care about efficient performance, contact Sterling TT to learn more about bespoke heat exchanger solutions in the oil and gas industry.
Diesel engines power the oil rig’s drills, cranes and pumps, among other things. Cooling fluid circulates in the engines to keep them at operating temperature. That heat needs to be removed from the cooling fluid and that’s where a heat exchanger comes in. Without heat exchangers, the whole system would overheat.
Heat exchangers are used in utility systems, such as cooling water systems and HVAC (heating, ventilation, and air conditioning) systems on the platform. These systems help maintain the optimal operating conditions for various equipment.
Compressed air or natural gas is also used in the oil extraction process, and compressed air is created with compressors. Heat exchangers are used for interstage cooling (cooling the gas while it is being compressed) or aftercooling (cooling after the gas is compressed). One use of compressed gas is for a “gas lift”, where the compressed gas expands to push oil up a tube to the surface. Without heat exchangers, the compression process would be far more inefficient, and therefore so would the whole oil extraction process.
Power generation systems
Heat exchangers are often used in power generation systems on oil rigs. They help regulate the temperature of the fluids used in power generation processes, such as those involving gas turbines or other power generation equipment.
The type of heat exchangers varies, including shell-and-tube exchangers, air-to-water coolers, and other designs based on the requirements of the processes involved. Safety and environmental considerations also play a crucial role in determining the location and design of heat exchangers on oil rigs and platforms.
Is your company involved in offshore oil and gas?
At Sterling TT, we have decades of experience in the oil and gas industry. Whether you’re seeking heat exchangers for offshore or onshore applications, get in touch with our team of experts. We offer heat exchangers that are robust, reliable, and easy to maintain.