Month: March 2017

The Albuskjell oil and gas/condensate field lay 21 kilometres north-west of the Ekofisk Complex and extended across blocks 1/6 and 2/4, licensed to Norske Shell and the Phillips group respectively. It was later unitised on a 50-50 basis.

Shell drilled discovery well 1/6-1X in 1972, in cooperation with Phillips, close to the boundary with block 2/4. The Albuskjell structure formed rather differently from other fields in the Greater Ekofisk area. Deposited 22-55 million years ago over a salt dome, its producing layer comprises carbonate rocks with some thin strips of shale.

Albuskjell 1/6 A produced from 11 wells and was tied back by gas and oil pipelines via Albuskjell 2/4 F to Ekofisk 2/4 R. A separate flare stack was linked to the platform by a bridge.

Processing comprised an oil/gas separator. Gas was dehydrated and compressed before export in a 24-inch pipeline. The separated oil was exported through an 18-inch line. Before being piped away, the oil and gas passed through a fiscal metering station to measure the volumes produced.

The platform was designed in a collaboration between Cork Shipyard, Oil Industry Services (OIS), Nylands Verksted, Tangen Verft, Aker Stord and Thyssen. Morco AS was the drilling contractor.

Like that on Albuskjell 2/4 F, the jacket (support structure) for 1/6 A was unusual because its two topmost frames were filled with water to prevent them heating up in the event of a fire. It was built at Aker Verdal, with the module support frame (MSF) fabricated by Aker Stord.

The living accommodation provided 46 beds, later 96.
The water depth was 70 metres.
Total weight of platform and pipelines was 25 300 tonnes.
The tip of the flare stack was 94 metres above sea level.
The derrick was 74 metres tall.

It was originally designed as a combined production, drilling and accommodation platform, but the derrick and drilling equipment were removed as early as 1979. The accommodation module with helideck was replaced in 1983 to increase beds from 46 to 96. The actual lifting operation was performed by the Balder crane barge from Heerema/Seaway.

When the Albuskjell field was shut in during July 1998, it had produced
46 million barrels or 7.353865 million standard cubic metres (scm) of oil
15.53439 billion scm of gas
990 139 tonnes of natural gas liquids (NGL)

Wellheads

Once a well has been fully drilled, it is completed for either production or injection. The purpose of well completion is to isolate the oil/gas production flow (wellstream) so that the whole path from reservoir to platform topside is leak-free.

This is achieved by running production tubing inside the casing (well liner) installed during drilling. These tubes are attached to the wellhead on the platform, which seals the top of the casing and provides a system for controlling pressure in the well.

Reservoir pressure causes crude oil/gas to flow up through the production tubing to the wellhead, which contains master and choke valves. These make it possible to shut down a producer or to adjust the desired volume of flow from each producer.

The Xmas tree (so called because of its shape) is installed on the wellhead. It contains control and work valves, such as the one for injecting diesel oil and various chemicals into the production tubing. Wellhead and Xmas tree form part of well control system.

The automatic master valve sits in the vertical section of the wellhead and is kept open by hydraulic pressure. Supported by the manual master valve, it represents the first barrier for shutting down the well.

Designed to cope with a substantial pressure drop, the choke valve is used to regulate wellstream flow and pressure from the individual well. This ensures that pressures in and production rates from all the wells are virtually identical.

The wellstream flowing through the choke valve is conducted to the production or the test manifold through a block valve before entering the separator on the platform.

Historie, 2007, fjerning av lette struktrer, Albuskjell 1/6 A

Ekofisk 2/4 B, engelsk,

Albuskjell 1/6 A

Separation

The wellheads delivered a mix of crude oil, natural gas and water through either the production or the test manifold to the separators. This mix had to be split into its various components for further processing on the platform.

Albuskjell 1/6 A

Measuring 20 metres long, the production separator was a horizontal tank with a diameter of four metres. It worked on the principle that the heaviest components in the tank would sink to the bottom while the lighter liquids and gas remained higher up.

This was a three-phase device with a lower phase of water, a middle one of crude oil and an upper gas phase. It was equipped internally with inlet deflectors, seven perforated guide plates and a demister for the gas outlet.

The test separator worked on the same principle, but was rather smaller. Its applications included testing the production rate from a single well so that the choke in the wellhead could be correctly adjusted.

Gas compression

Compression was needed to increase the gas pressure before it entered the pipeline which ran to Ekofisk 2/4 R. The train comprised a gas cooler, suction scrubber and gas compressor.

   Gas cooler. This reduced the temperature of gas emerging from the separator in order to prevent the compressor from running too hot. The gas circulated around a set of water-cooled tubes, lowering its temperature to 27°C.

   Suction scrubber. Once the gas was cooled, some liquids had to be removed in this device. It comprised a vertical tank four metres tall and two metres in diameter.

   Gas compressor. Driven by a gas turbine, this unit increased the pressure from 465 pounds per square inch gauge (psig) to 1 305psig while also raising the gas temperature from 27°C to 100°C.

Gas dehydration

albuskjell 1/6 a,

Gas piped to Ekofisk 2/4 R had to be completely free of water to avoid ice or hydrate (hydrocarbon ice) plugs forming in the pipeline during transport through the cold seawater.

The gas was first cooled from 100°C to 27°C in two stages before being mixed with triethlyene glycol – a liquid which attracts water. After it had been dehydrated in this way, the gas was reheated to 65°C in a heat exchanger.

In all, the dehydration system comprised the gas/gas heat exchanger, the gas aftercooler and the glycol contactor.

   Gas/gas heat exchanger. This had two functions – cooling down the incoming gas from 100°C to 60°C and heating up the outgoing gas from 27°C to 65°C. Two gas streams passed each other in the unit.

   Gas aftercooler. This contained a number of water-cooled tubes which the gas circulated around to reduce the temperature from 60°C to 27°C.

   Glycol contactor. This unit comprised a vertical tank 13 metres tall by two metres in diameter. The gas bubbled up through a number of vessel filled with glycol and ended up dehydrated at the top. Water-saturated glycol was circulated out and replaced by more dry chemical.

Fiscal metering

Oil and gas processed on the platform and exported to the Ekofisk Complex was metered in a metering station on 1/6 A. Data from these instruments were transmitted to a Daniel computer for processing before being transferred to the Ekofisk Complex via a telemetric link.

Corresponding meters were also provided for gas consumed on the platform and for the flare boom.

 Gas metering. The gas meter comprised a tube containing pressure and temperature gauges, a densimeter and a flow orifice. When the gas passed through the orifice, its speed rose and its pressure fell. Knowing the density and composition of the gas meant the pressure drop could be used to measure the quantity exactly.

albuskjell 1/6 a

Oil metering. A turbine flow meter was used to meter oil. Small magnets located on the outer edge of the rotor transmitted signals to sensors in the rotor housing. The latter could then measure the speed at which the rotor turned, and thereby arrive at the exact amount of liquid flowing through the meter.

Calibration. Such turbine flow meters had to be calibrated regularly to ensure accurate measurements. Known as a meter prover, this system comprised a horseshoe-shaped test loop which contained a rubber ball.

During calibration, oil was conducted through the loop and pushed the ball ahead of it. Measuring how long the ball took to complete the circuit, given that the loop’s exact volume was known, made it possible to measure oil flow accurately. These data were then compared with the pulses from the turbine flow meter.

Albuskjell 1/6 A

Control room

The control room was the platform’s heart, monitoring and controlling all important processes on board.

Utilities

Glycol regeneration Glycol coming from the gas dehydration facility had a pressure of 1 205psig and was saturated with water and gas. After its pressure had been reduced, the gas was removed in a degassing pot.

The glycol was then filtered and heated in the regenerator to evaporate the water, and passed through pumps to reach the same pressure as the dehydration unit before being returned to it.

Gas pipeline pigging. To remove slag and water from the gas pipeline, a sphere was launched into it at 1/6 A and followed the gas flow to Ekofisk 2/4 R where removal took place.

Oil pipeline pigging. The pig in the oil pipeline had a different shape to the unit used for the gas pipeline, but otherwise functioned in the same way.

Albuskjell 1/6 A,

Albuskjell 1/6 A,

Power supply

Electricity for the platform came from the generator room, where four generating sets were driven by Kongsberg gas turbines. Two of these turbines were later removed and replaced by a diesel engine. Electric switchboards were installed in the module above the generators. The working voltage was 480V.

Other utilities

Other utilities on the platform included fire extinguishing and rescue systems, instrument air, chemical injection and drinking water.

Also provided were diesel and lube oils, gas lift equipment, a workshop, helideck, accommodation module, flare boom, radio communications and so forth.

Production ceased in 1998, and the platform became unmanned in 1999 with remote monitoring from Ekofisk 2/4 K. After the processing plant had been cleaned and the wells were plugged and secured, the platform was removed during 2013.

Historie, 2007, fjerning av lette struktrer, forsidebilde,

Albuskjell 1/6 A, yrke, telegrafisk,

Albuskjell 1/6 A

Albuskjell 1/6 A, forpleining, kantine,

Albuskjell 1/6 A og 2/4 F,

ALBUSKJELL 1/6 A

Åm was born at Årdal in the Sogn district of western Norway in 1944, and grew up in Oppdal and Volda/Ørsta where he proved an able pupil at school. 

He opted to study mining engineering at the Norwegian Institute of Technology (NTH) in Trondheim, graduating with honours in 1967. 

Åm’s first job was with the Norwegian Geological Survey (NGU), again in Trondheim, where he worked and conducted research for six years. One of his jobs was to interpret aeromagnetic measurements of sub-surface rocks made from the air, which provide valuable information on geology and prospects for finding petroleum. In a series of publications, he described the big sedimentary basins identified in the Skagerrak between Norway and Denmark and in the Norwegian and Barents Seas. 

He joined the Norwegian Petroleum Directorate (NPD) in 1974, serving as a section head in the resource department and a principal engineer in the safety department. 

That was followed by three years with Statoil, where he became the state oil company’s first vice president for research and development. His appointments at the time included chairing a research programme on offshore safety, which led to legislation enacted by the Storting (parliament) and a bigger research effort. 

Joining Phillips

olje og gassveteran knut åm,

Åm secured a job with Phillips in 1982 and was soon sent to the head office at Bartlesville in Oklahoma to get better acquainted with the company and its corporate culture. 

After a year in the USA, he returned to the company’s Tananger office outside Stavanger and became the first Norwegian to serve as offshore manager for the Greater Ekofisk Area (GEA). 

That put him in charge of 23 platforms, with responsibility for the waterflooding programme as well as the project to jack up a number of the installations. These major developments extended the producing life of the GEA and sharply increased estimates for recoverable reserves from its fields. 

Åm led this work during difficult times, with low oil prices and the need to implement cost savings and overcome substantial financial challenges. As if that were not enough, he also taught at the University of Bergen from 1985 to 1990 as an adjunct (part-time) professor of applied geophysics. 

First Norwegian chief executive

Knut åm,

After heading operations in the Permian and San Juan Basins at Odessa, Texas, from 1988-91, Åm became the first Norwegian president and managing director for Phillips Petroleum Norway. 

That put him in charge of 3 000 employees in the GEA as well as in Tananger, Oslo, Teesside and Emden. This was when a redevelopment of Ekofisk was planned, along with the future cessation and removal of old platforms.[REMOVE]Fotnote: https://www.fylkesmannen.no/globalassets/fm-rogaland/dokument-fmro/felles-og-leiing/brev-og-artiklar/fm-tale-til-knut-am.pdf 

By 1996, Åm was back in Bartlesville – now as vice president and head of all exploration and production in Phillips. He stayed in that job until retiring in the USA during 1999.

Offices and committees

But his working life did not end there. Appointments from 1999 to 2007 include membership of the Statoil board – and many similar posts can be mentioned. 

Åm has been president of the Norwegian Geological Council and the Norwegian Petroleum Society, and chair of the Norwegian Oil Industry Association (now the Norwegian Oil and Gas Association). 

He led the exhibition committee of the 1996 ONS oil show in Stavanger, and has chaired Bergen’s Christian Michelsen Research institute as well as the industrial council of the Norwegian Academy of Science and Letters.  

In addition to chairing Hitec ASA, he has been a director of several technology companies. 

Mention must also be made of the improved recovery committee appointed by the Ministry of Petroleum and Energy with Åm as chair. This produced a report in September 2010 which presented 44 specific measures for improving the recovery factor on the Norwegian continental shelf (NCS). 

Through his work and many appointments, Åm has been acclaimed for a combination of expertise, creativity and determination.  He also demonstrated the ability to tackle the requirements of Norway as a nation as well as the industry and its employees – not least with regard to the working environment and safety in a demanding and risky offshore industry. 

Optimist

In retirement, Åm is an optimist – with regard to the climate as well. “I’m very concerned with nature, but believe we should extract the resources it’s given us,” he told Otium in 2016. 

“Norway could have a long and good future in the oil and gas industry if people give it more support. Exploring for new deposits is important, but we should also seek to achieve a far better recovery factor from both new and existing fields.” 

“You can naturally concentrate on life’s negative aspects. Then everything’s simply awful. I think you’ll be a far happier person if you prefer to see the positive side of life. I call that self-motivation. We need more of that in the energy sector.”[REMOVE]Fotnote: https://api.optimum.no/sites/default/files/PDF/optimum-magasinet-2016.pdf