Perdido (Spanish for lost) is the deepest floating oil platform in the world at a water depth of about 2,450 meters (8,040 feet) operated by the Shell Oil Company in the Gulf of Mexico. [1] The platform is located in the Perdido fold belt which is a rich discovery of crude oil and natural gas. The Perdido spar began production in 2010 and its peak production is 100,000 barrels of oil equivalent (c. 16000 m3/d) and 200 million cubic feet of gas per day (c. 5.7×106 m3/d).
The spar and the topsides of the Perdido were constructed separately and then assembled in its final position in the Gulf of Mexico.
The Perdido's hulk or spar was constructed by Technip in Pori, Finland. A barge shipped the 22,000 tonne spar 13,200 kilometres (8,200 miles) from the Baltic Sea to the Gulf of Mexico. After floating the spar, it was towed to its final home above the Alaminos canyon 320 kilometres (120 miles) from the shore. The spar was rotated by the Balder from a horizontal to a vertical floating position by pumping water through hoses attached to the spar. It was then anchored by the Balder to piles in the seafloor.
The platform has three decks or topsides which support the oil and gas processing units, a drilling rig and living quarters for the workers. The topsides were designed by Alliance Engineering and constructed by Kiewit Offshore in Corpus Christi, Texas. The temperature difference between Finland and Texas posed a challenge in assembling the pieces as the components built in cold of northern Europe expand in the heat of the Gulf of Mexico. Computer-guided lasers marked out the measurements to ensure precision. After the decks were constructed, in March 2009 the Thialf lifted the 9,500 tonne topsides onto four posts on the spar and slotted it into position.
The Perdido has the ability to adjust the tension of the mooring cables which allows it to move around in the area of a soccer field. This is used to be placed – if needed – directly above one of the 22 wellheads on the seafloor.
Operated by Shell, with JV partners Chevron (37.5%) and BP (27.5%), the spar acts as a hub for and enables development of three fields Great White, Tobago, and Silvertip. The oil and gas fields beneath the platform lie in a geological formation holding resources estimated at 3–15 billion barrels of oil equivalent according to a report by the BSEE, formerly known as the MMS. At peak production, Perdido processes 100,000 barrels of oil equivalent a day, and 200 million cubic feet of gas.
Perdido extracts oil from 35 of subsea wells, of which 22 lie beneath the spar, while 13 wells are located eight miles west of the platform. These are connected via a 44 kilometre (27 mile) network of pipelines on the ocean floor the manifold below the platform, where the oil is pumped upwards in five flexible pipes called risers. This complicated subsea installation is needed, as the reservoir pressure is rather low which means the transport from the seafloor to the ocean surface needs pumps, the number of which had to be minimized. [2]
A workforce of 172 people keep it up and running. They work in 12-hour shifts for 2 weeks followed by 2 weeks off back on land.
The platform has extensive safety equipment to protect workers in this remote location. It has the largest rescue boat used on any Shell facility, which has room for 24 people. The living quarters are blast-resistant. Perdido's helipad can accommodate two Sikorsky S-92 helicopters that can carry 19 passengers each.
An oil platform is a large structure with facilities to extract and process petroleum and natural gas that lie in rock formations beneath the seabed. Many oil platforms will also have facilities to accommodate the workers, although it is also common to have a separate accommodation platform bridge linked to the production platform. 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. In some arrangements the main facility may have storage facilities for the processed oil. Remote subsea wells may also be connected to a platform by flow lines and by umbilical connections. These sub-sea facilities may include one or more subsea wells or manifold centres for multiple wells.
A floating production storage and offloading (FPSO) unit is a floating vessel used by the offshore oil and gas industry for the production and processing of hydrocarbons, and for the storage of oil. An FPSO vessel is designed to receive hydrocarbons produced by itself or from nearby platforms or subsea template, process them, and store oil until it can be offloaded onto a tanker or, less frequently, transported through a pipeline. FPSOs are preferred in frontier offshore regions as they are easy to install, and do not require a local pipeline infrastructure to export oil. FPSOs can be a conversion of an oil tanker or can be a vessel built specially for the application. A vessel used only to store oil is referred to as a floating storage and offloading (FSO) vessel.
A tension-leg platform (TLP) or extended tension leg platform (ETLP) is a vertically moored floating structure normally used for the offshore production of oil or gas, and is particularly suited for water depths greater than 300 metres and less than 1500 metres. Use of tension-leg platforms has also been proposed for offshore wind turbines.
The Brent field was an oil and gas field located in the East Shetland Basin of the North Sea, 186 kilometres (116 mi) north-east of Lerwick in the Shetland Islands, Scotland, at a water depth of 140 metres (460 ft). The field operated by Shell UK Limited was discovered in 1971 and was once one of the most productive parts of the UK's offshore assets but has reached the stage where production is no longer economically viable. Decommissioning of the Brent field is complete with the exception of Brent C, which is producing from another field. The discovery well 211/26-1 was drilled in 1971 by the semi-submersible drilling rig "Staflo". This was a major surprise at the time as the nearest land in Scotland and Norway is composed of granite and other non reservoir metamorphic rocks.
In petroleum and natural gas extraction, a Christmas tree, or tree, is an assembly of valves, casing spools, and fittings used to regulate the flow of pipes in an oil well, gas well, water injection well, water disposal well, gas injection well, condensate well, and other types of well.
Mars is a permanent offshore drilling and production tension-leg oil platform (TLP) operating in Mississippi Canyon blocks 762, 763, 806, 807, 850 and 851 in the Gulf of Mexico and was approved by the MMS in December 1992 with production beginning on July 8, 1996. The leases were acquired by Shell in 1985 and 1988. The platform is a joint venture between Shell Oil Company and BP, with Shell owning the majority share and operating the facility.
The Dunlin oilfield is situated 195 km northeast of Lerwick, Shetland, Scotland, in block number 211/23a and 211/24a. It was originally operated by Shell but was sold in 2008 and is now operated by Fairfield Energy and partners MCX.
The Cormorant oilfield is located 161 kilometres (100 mi) north east of Lerwick, Shetland, Scotland. It was discovered in September 1972 at a depth of 150 metres (490 ft). The oil reservoir is located at a depth of 2,895 metres (9,498 ft). Production started in December 1979 from the Cormorant Alpha platform and operates from two platforms and an underwater manifold centre.
A blowout is the uncontrolled release of crude oil and/or natural gas from an oil well or gas well after pressure control systems have failed. Modern wells have blowout preventers intended to prevent such an occurrence. An accidental spark during a blowout can lead to a catastrophic oil or gas fire.
The Clair oilfield is an offshore oil field in Scottish territorial waters 75 kilometres (47 mi) west of Shetland in water depths of up to 140 metres (460 ft). The field is the largest oilfield on the UK Continental Shelf with an estimated 8 billion barrels of oil-in-place, according to the BP Plc's website. It extends over an area of some 220 square kilometres (85 sq mi), covering five licence blocks.
Offshore drilling is a mechanical process where a wellbore is drilled below the seabed. It is typically carried out in order to explore for and subsequently extract petroleum that lies in rock formations beneath the seabed. Most commonly, the term is used to describe drilling activities on the continental shelf, though the term can also be applied to drilling in lakes, inshore waters and inland seas.
Subsea technology involves fully submerged ocean equipment, operations, or applications, especially when some distance offshore, in deep ocean waters, or on the seabed. The term subsea is frequently used in connection with oceanography, marine or ocean engineering, ocean exploration, remotely operated vehicle (ROVs) autonomous underwater vehicles (AUVs), submarine communications or power cables, seafloor mineral mining, oil and gas, and offshore wind power.
"Offshore", when used in relation to hydrocarbons, refers to operations undertaken at, or under the, sea in association with an oil, natural gas or condensate field that is under the seabed, or to activities carried out in relation to such a field. Offshore is part of the upstream sector of the oil and gas industry.
A spar is a marine structure, used for floating oil/gas platforms. Named after navigation channel Spar buoys, spar platforms were developed as an extreme deepwater alternative to conventional platforms. The deep draft design of spars makes them less affected by wind, wave, and currents and allows for both dry tree and subsea production.
Draugen is an oil field in the Norwegian Sea with a sea depth of 250 metres (800 ft). It has been operating by A/S Norske Shell until sold to AS OKEA in 2018. The field has been developed with a concrete fixed facility and integrated topside. Stabilized oil is stored in tanks in the base of the facility. Two flowlines connect the facility to a floating loading buoy.
Deepwater drilling, or deep well drilling, is the process of creating holes in the Earth's crust using a drilling rig for oil extraction under the deep sea. There are approximately 3400 deepwater wells in the Gulf of Mexico with depths greater than 150 meters.
The Macondo Prospect is an oil and gas prospect in the United States Exclusive Economic Zone of the Gulf of Mexico, off the coast of Louisiana. The prospect was the site of the Deepwater Horizon drilling rig explosion in April 2010 that led to a major oil spill in the region from the first exploration well, named itself MC252-1, which had been designed to investigate the existence of the prospect.
The Helix fast-response system (HFRS) is a deep-sea oil spill response plan licensed by HWCG LLC, a consortium of 16 independent oil companies, to respond to subsea well incidents. Helix Energy Solutions Group designed the Helix fast-response system based on techniques used to contain the 2010 Gulf of Mexico oil spill. On February 28, 2011 the drilling moratorium imposed as a result of the spill ended when the United States Department of the Interior approved the first drilling permit based on the availability of the HFRS to offshore oil companies.
Olympus is a tension leg platform oil rig, planned as a further development of the Mars field.