The Harding oilfield is a small

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 presence ...

operated by

TAQA The Abu Dhabi National Energy Company, PJSC (TAQA) is a government controlled energy holding company of Abu Dhabi, United Arab Emirates. TAQA (Arabic for Energy) is one of Abu Dhabi's flagship companies and as such has an important role to play ...

, in the

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

block 9/23b, approximately North-East of

Aberdeen Aberdeen (; sco, Aiberdeen ; gd, Obar Dheathain ; la, Aberdonia) is a city in North East Scotland, and is the third most populous city in the country. Aberdeen is one of Scotland's 32 local government council areas (as Aberdeen City), and ...

and in of water.

Discovery and development

The field was discovered in 1987, when

oil An oil is any nonpolar chemical substance that is composed primarily of hydrocarbons and is hydrophobic (does not mix with water) & lipophilic (mixes with other oils). Oils are usually flammable and surface active. Most oils are unsaturated ...

was found in

Eocene The Eocene ( ) Epoch is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene' ...

at a depth of . It was originally named the ''Forth'' field, but was renamed in 1993 in memory of David Harding who was Chief Executive of BP Exploration's UK operations during the field appraisal. The abundance of

naphthenic acid Naphthenic acids (NAs) are a mixture of several cyclopentyl and cyclohexyl carboxylic acids with molecular weight of 120 to well over 700 atomic mass units. The main fraction are carboxylic acids with a carbon backbone of 9 to 20 carbons. McKee et ...

in the oil however made the development unattractive at the time. The crude is heavy and naphthenic and is generally of a lower value compared to other North Sea oils. Consequently, the decision was made to export it by tanker rather than co-mingle it in a pipeline. The oil from the Harding field is therefore stored offshore. The selected development solution was a heavy-duty steel jack-up production unit based on a proprietary design by

Technip Technip S.A. was a company that carried out project management, engineering and construction for the energy industry; in 2017 it completed a merger with FMC Technologies to form TechnipFMC. Its headquarters were in the 16th arrondissement of Pa ...

Geoproduction resting on a concrete gravity base which had storage for of oil.Offshore Technology website : http://www.offshore-technology.com/projects/harding

Reservoir

The Harding field is in fact composed of five separate

reservoirs A reservoir (; from French ''réservoir'' ) is an enlarged lake behind a dam. Such a dam may be either artificial, built to store fresh water or it may be a natural formation. Reservoirs can be created in a number of ways, including control ...

. The largest is the central field, hosting most of the

wells Wells most commonly refers to: * Wells, Somerset, a cathedral city in Somerset, England * Well, an excavation or structure created in the ground * Wells (name) Wells may also refer to: Places Canada *Wells, British Columbia England * Wells ...

as well as the site of the gas re-injection. There is also smaller fields to the North, North-East, South and South-East, all named as such. This has led to a unique well naming system in addition to the traditional use of DTI well numbers and slot numbers, which identifies a well by the particular field in which it has been drilled and its purpose. The formations are unconsolidated, making the

likely to produce sand. In order to prevent this, traditional cased hole completions are not used on any of the Harding wells. Instead, all wells used sandscreens.

Production

Harding presently (2017) produces around of oil, from 15 wells, and of gas, most of which is re-injected. All production wells are

gas lift Gas lift or bubble pumps use the artificial lift technique of raising a fluid such as water or oil by introducing bubbles of compressed air, water vapor or other vaporous bubbles into the outlet tube. This has the effect of reducing the hydrostati ...

ed. The central reservoir is supported by two water injection wells and a gas injector. The south and north fields have the support of one water injector each, though the injector in the north field is currently suspended. Well fluids are processed in the 2-phase (liquid and gas) 1st Stage Separator.Harding Oil System Schematic (2001) The separated liquids flow to the 3-phase (oil, gas and water) 2nd Stage Separator. After metering the oil stream is either directed to the oil storage tanks and thence to a tanker or to the Harding Oil Pipeline. Vapour from the 2nd Stage Separator is compressed in the LP Compressor and mixed with the vapour from the 1st Stage Separator and is transferred to the gas system. There is also a Test Separator for well testing. Oil flows to the inlet of the 1st Stage Separator, and vapour to the gas system. All produced water is reinjected. In addition there are two aquifer wells to provide extra injection water, if required. Without a pipeline, the bulk of the produced

gas Gas is one of the four fundamental states of matter (the others being solid, liquid, and plasma). A pure gas may be made up of individual atoms (e.g. a noble gas like neon), elemental molecules made from one type of atom (e.g. oxygen), or ...

has been reinjected into the cap of the central

reservoir A reservoir (; from French ''réservoir'' ) is an enlarged lake behind a dam. Such a dam may be either artificial, built to store fresh water or it may be a natural formation. Reservoirs can be created in a number of ways, including contro ...

, sequestering it for production after 2021, when the platform is converted to a gas producer after decline of oil production.

Harding Area Gas Project

The Harding reservoir also contains gas, which TAQA hopes to develop at some future stage. BP announced plans in 2006 to develop the gas resources via the Harding Area Gas Project. A combination of factors has made this original development concept uncompetitive; particularly low gas prices and increased development costs. The project is being recycled and TAQA is in discussion with its partner,

Maersk Oil Maersk Oil ( da, Mærsk Olie og Gas A/S) was a Danish oil and gas company owned by the A. P. Moller-Maersk Group. with a maximum operated production of 550,000 barrels of oil equivalent per day. Production came from Denmark, the UK, Qatar, Kazak ...

, to investigate alternative development options for the gas resources in the area.

References

{{Reflist BP oil and gas fields North Sea oil fields Oil fields of Scotland