The Buzzard Oil Field is an

oil field A petroleum reservoir or oil and gas reservoir is a subsurface accumulation of hydrocarbons contained in porous or fractured rock formations. Such reservoirs form when kerogen (ancient plant matter) is created in surrounding rock by the prese ...

located in the

North Sea The North Sea lies between Great Britain, Denmark, Norway, Germany, the Netherlands, Belgium, and France. A sea on the European continental shelf, it connects to the Atlantic Ocean through the English Channel in the south and the Norwegian Se ...

Blocks 19/10, 19/5a, 20/6 and 20/1s. It was discovered in 2001 by PanCanadian, and developed initially by PanCanadian's successor EnCana and then by

Nexen Nexen may refer to: * Nexen Energy, now CNOOC Petroleum North America, a Canadian oil and gas company * Nexen Tire, a Korean tire manufacturer *NEXEN, an online platform used by BNY {{disambiguation ...

. The oil field was initially operated and owned by

which is now a subsidiary of China's CNOOC.

The field

The total

proven reserves Proven reserves (also called measured reserves, 1P, and reserves) is a measure of fossil fuel energy reserves, such as oil and gas reserves and coal reserves. It is defined as the "quantity of energy sources estimated with reasonable certaint ...

of the Buzzard oil field are , and production will be centered on per day. The Buzzard reservoir has a low gas/oil ratio and requires pressure maintenance through water injection. Buzzard’s oil consists of medium sour crude: 32.6° API, 1.4% sulphur.

Infrastructure

The Buzzard field development comprises four bridge-linked steel platforms: the wellhead facilities (W) for up to 27 production wells, production facilities (P), a platform supporting accommodation and utilities (UQ) and an oil stripper platform (PS).

Processing

The oil processing facilities comprise a 3-phase (oil/vapour/water) Production Separator. Oil from the separator flows to the 3-phase Second Stage Separartor. Oil from the latter is 'spiked' with

Natural Gas Liquids Natural-gas condensate, also called natural gas liquids, is a low-density mixture of hydrocarbon liquids that are present as gaseous components in the raw natural gas produced from many natural gas fields. Some gas species within the raw natura ...

(NGL) from the gas dewpointing plant, then injected with a

hydrogen sulphide Hydrogen sulfide is a chemical compound with the formula . It is a colorless chalcogen-hydride gas, and is toxic, corrosive, and flammable. Trace amounts in ambient atmosphere have a characteristic foul odor of rotten eggs. Swedish chemist Ca ...

(H₂S) scavenger chemical prior to metering and export.Process Sketch Oil and Gas export (2006) Produced water from the Second Stage Separator is recycled to the Production Separator, and from there to the produced water treatment facilities using hydrocyclones before overboard disposal. Vapour from the two Separators is compressed in an Offgas Compressor and a LP/HP compressor. Compressed gas passes through a Mercury Removal Bed and an Acid Gas Removal system, which uses a

counter-current flow Countercurrent exchange is a mechanism between two flowing bodies flowing in opposite directions to each other, in which there is a transfer of some property, usually heat or some chemical. The flowing bodies can be liquids, gases, or even solid ...

amine In chemistry, amines (, ) are organic compounds that contain carbon-nitrogen bonds. Amines are formed when one or more hydrogen atoms in ammonia are replaced by alkyl or aryl groups. The nitrogen atom in an amine possesses a lone pair of elec ...

solvent, and then through a Mercaptans Removal Bed. The gas is dehydrated in a gas dehydration system which uses a counter-current flow of

glycol A diol is a chemical compound containing two hydroxyl groups ( groups). An aliphatic diol may also be called a glycol. This pairing of functional groups is pervasive, and many subcategories have been identified. They are used as protecting gro ...

. After dehydration the gas is cooled and passes through a Joule-Thomson valve to reduce its pressure and hence its temperature to remove liquids and achieve a gas hydrocarbon

dewpoint The dew point is the temperature the air needs to be cooled to (at constant pressure) in order to produce a relative humidity of 100%. This temperature depends on the pressure and water content of the air. When the air at a temperature above the ...

. Natural Gas Liquids are separated and co-mingled with the export oil stream. Gas is compressed in the HP Compressors, some is used as

gas lift A gas lift or bubble pump is a type of pump that can raise fluid between elevations by introducing gas bubbles into a vertical outlet tube; as the bubbles rise within the tube they cause a drop in the hydrostatic pressure behind them, causing t ...

on the production wells, some as fuel gas, and the remainder is exported.

Export

Oil is exported from Buzzard via an 18 inch pipeline from the Buzzard processing platform to the nearest point in the Forties to Cruden Bay System, approximately 28 km away. Oil flows to Cruden Bay and then onto the Kinneil Terminal. First oil was produced in December 2006. Gas is exported via a pipeline from Buzzard to the Captain ‘T’ point on the UK

Frigg Frigg (; Old Norse: ) is a goddess, one of the Æsir, in Germanic mythology. In Norse mythology, the source of most surviving information about her, she is associated with marriage, prophecy, clairvoyance and motherhood, and dwells in the wetl ...

pipeline 29 km away. From there the gas is transported to the St Fergus Gas Terminal. Fuel gas can also be imported onto Buzzard from the Frigg pipeline.

Production history

Buzzard was the largest discovery in UK waters for 20 years when it was found in 2001 and went on to become the largest-producing field in the region after starting up in 2007. Once at a peak of more than of oil equivalent per day in 2009, production has decreased to of oil equivalent per day as of May 2020, according to Oil and Gas Authority (OGA) figures. Buzzard was temporarily shutdown twice in late 2019 for repairs to topside pipework.

Expansion

Buzzard Phase 2 is a bid to go after additional reserves to the north of the main field with a subsea development tied-back to it, with expected peak production of of oil equivalent per day. The first stage includes installation of a subsea manifold, a new processing module for the platform and drilling of four production wells. First oil from Buzzard Phase 2 was expected in late 2020 but as of August 2020, CNOOC postponed the project to 2021. Chrysaor stated that the drilling results for Buzzard Phase 2 was "towards the lower end of expectations," with the project now expected to come on stream in December 2021.

References

{{coord missing, North Sea North Sea oil fields Oil fields of the United Kingdom