Oil from the Sleipner field.
The Sleipner gas field is a
natural gas 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 ...
in the block 15/9
of 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 ...
, about west of
Stavanger
Stavanger (, , American English, US usually , ) is a city and municipalities of Norway, municipality in Norway. It is the fourth largest city and third largest metropolitan area in Norway (through conurbation with neighboring Sandnes) and the a ...
,
Norway
Norway, officially the Kingdom of Norway, is a Nordic country in Northern Europe, the mainland territory of which comprises the western and northernmost portion of the Scandinavian Peninsula. The remote Arctic island of Jan Mayen and t ...
. Two parts of the field are in production, Sleipner West (proven in 1974), and Sleipner East (1981).
[
][
] The field produces natural gas and light oil condensates from sandstone structures about below sea level. It is operated by
Equinor
Equinor ASA (formerly Statoil and StatoilHydro) is a Norwegian state-owned multinational energy company headquartered in Stavanger. It is primarily a petroleum company, operating in 36 countries with additional investments in renewable energy. I ...
. The field is named after the steed
Sleipnir
In Norse mythology, Sleipnir (Old Norse: ; "slippy"Orchard (1997:151). or "the slipper"Kermode (1904:6).) is an eight-legged horse ridden by Odin. Sleipnir is attested in the ''Poetic Edda'', compiled in the 13th century from earlier traditional ...
in
Norse mythology
Norse, Nordic, or Scandinavian mythology is the body of myths belonging to the North Germanic peoples, stemming from Old Norse religion and continuing after the Christianization of Scandinavia, and into the Nordic folklore of the modern period ...
.
Reserves and production
As of the end of 2005, the estimated recoverable reserves for the Sleipner West and East fields were 51.6 billion cubic meters of natural gas, of
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 natur ...
, and 3.9 million cubic meters of condensates.
[ Daily production of the field in 2008 was oil equivalents per day, 36 million cubic meters of natural gas per day, and 14,000 cubic meters of condensate per day. In an updated 2017 report, the Norway Petroleum Directorate estimates 2.72 million cubic meters of oil, 11.72 billion cubic meters of natural gas, 0.67 million tons of natural gas liquids, and 0.07 million cubic meters of condensates remain in the reserves.
Sleipner field consists of four platforms. The field is planted with 18 production wells.] The Sleipner A platform is located on the Sleipner East and the Sleipner B platform is located on the Sleipner West. Sleipner B is operated remotely from the Sleipner A via an umbilical cable
An umbilical cable or umbilical is a cable and/or hose that supplies required consumables to an apparatus, like a rocket, or to a person, such as a diver or astronaut. It is named by analogy with an umbilical cord. An umbilical can, for example, ...
. The Sleipner T carbon dioxide
Carbon dioxide (chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is transpar ...
treatment platform is linked physically to the Sleipner A platform by a bridge and to the Sleipner B wellhead platform by carbon dioxide flow line.[
][ The Sleipner Riser platform, serving the Langeled and ]Zeepipe
The Zeepipe is a natural gas transportation system to transport North Sea natural gas to the receiving terminal at Zeebrugge in Belgium.
The total costs of Zeepipe system is around 24.2 billion NOK. It is owned by Gassled partners and opera ...
pipelines, is located on the Sleipner East field.
Carbon capture and storage project
The Sleipner Vest (West) field is used as a facility for carbon capture and storage
Carbon capture and storage (CCS) or carbon capture and sequestration is the process of capturing carbon dioxide (CO2) before it enters the atmosphere, transporting it, and storing it (carbon sequestration) for centuries or millennia. Usually th ...
(CCS).[
] It is the world's first offshore CCS plant, operative since September 15, 1996.[
] The project, in the initial year, proved insecure due to sinking top sand. However, after a re-perforation and an installation of a gravel layer in August 1997, CCS operations were secure. As of 2018, one million tonnes of have been transported and injected into the formation yearly since 1996. The project summary reports a capacity of up to 600 billion tonnes (~660 billion tons).
The Sleipner West field has up to 9% concentration; Norway only allows 2.5% before imposing production export quality penalties, which may have been NOK 1 million/day ( ~$120,000US/ day). Operating costs are US$17 / ton of injected, however, the company does not pay Norway's carbon tax of 1991 and receives carbon credit in the EU's emissions trading system. Before the carbon tax, industries released poor quality into the atmosphere. In a business-as-usual scenario, Norway's emissions would have had a total increase of 3% over 20 years if not for the CCS experiment. Carbon dioxide is treated on the Sleipner T treatment platform. After that carbon dioxide is transported to the Sleipner A platform where it is injected into the Utsira formation through a dedicated well 1000 meters under the seabed.[
] Using time-lapse gravity and seismic methods, the pioneering Sleipner carbon capture project confirmed the technological viability of injecting and measuring in an offshore reservoir, as well as the effectiveness of mitigating emissions through stable storage. To avoid possible leakages that can result in health hazards and environmental destruction, above the Utsira Formation injection site lies 30 seafloor gravity stations for monitoring under the title, Saline Aquifer Storage. These sites monitor microseismic activity along with gravitational forces and depth metrics. Seafloor height, natural gas production, and tidal shifts determine the gravity measured.
Explicitly regulated under Norway's petroleum law in December 2014 and in line with the EU's 2009/31/EC directive, monitoring objectives focus on assessing gas movement, shell stability, and the effectiveness of remedy scenarios in case of leakage. From 2002 to 2005, measurements identified vertical changes in established metric boundaries, most likely attributed to erosion
Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust, and then transports it to another location where it is deposited. Erosion is distin ...
and marine life
Marine life, sea life, or ocean life is the plants, animals and other organisms that live in the salt water of seas or oceans, or the brackish water of coastal estuaries. At a fundamental level, marine life affects the nature of the planet. M ...
. Onsite geochemical
Geochemistry is the science that uses the tools and principles of chemistry to explain the mechanisms behind major geological systems such as the Earth's crust and its oceans. The realm of geochemistry extends beyond the Earth, encompassing the e ...
and reservoir simulation
Reservoir simulation is an area of reservoir engineering in which computer models are used to predict the flow of fluids (typically, oil, water, and gas) through porous media.
The creation of models of oil fields and the implementation of ca ...
s reveal a main buildup of under the formation's cap seal. However, when the injections are eventually decommissioned, simulations show accumulation proximate to the cap seal in clay layers saturated with sand, which will result in solubility trapping. This solubility trapping, caused by the multiple layers of clay and sand, prevents from rising beyond and will ultimately turn to mineral trapping in the substrate. Furthermore, groundwater flow
Groundwater is the water present beneath Earth's surface in rock and soil pore spaces and in the fractures of rock formations. About 30 percent of all readily available freshwater in the world is groundwater. A unit of rock or an unconsolidate ...
facilitates better distribution of gases and depressurization, lowering the risk of leakage. The composition reaction of the mixture of clay, sand, and carbon is the determining factor of long-term stability in the Sleipner CCS project. As of 2007, measurements from the gravity stations revealed that the injection of into the Utsira Formation has not resulted in any noticeable seismic activity and that there have been no carbon dioxide leakages in the past 10 years.
Natural gas pipelines' operator Gassco
Gassco is a Norwegian state owned company that operates of natural gas pipes transporting annually of 100 billion cubic meter (bcm) of natural gas from the Norwegian continental shelf to Continental Europe and Great Britain.
15% of the total ...
had proposed to build a carbon dioxide pipeline from Kårstø
Kårstø is an industrial facility located near the village of Susort, along the Boknafjorden, in the municipality of Tysvær in Rogaland county, Norway. The site features a number of natural gas processing plants that refine natural gas and conde ...
to transport carbon dioxide from the now decommissioned Kårstø power station.[
] While injection pipelines do not succumb to rust
Rust is an iron oxide, a usually reddish-brown oxide formed by the reaction of iron and oxygen in the catalytic presence of water or air moisture. Rust consists of hydrous iron(III) oxides (Fe2O3·nH2O) and iron(III) oxide-hydroxide (FeO(OH ...
ing when transporting , transport pipelines experience low temperatures and high pressures, resulting in dew formation, and subsequently, rust.
Miocene Utsira Formation
The Miocene Utsira Formation is a large aquifer
An aquifer is an underground layer of water-bearing, permeable rock, rock fractures, or unconsolidated materials (gravel, sand, or silt). Groundwater from aquifers can be extracted using a water well. Aquifers vary greatly in their characterist ...
with a stable, layered clay seal. Distributed through multiple phases as a result of sea-level variations caused by glacial events in the Pliocene period, deposits date back to the late Miocene
The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recen ...
/ early Pliocene to early Pleistocene
The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fina ...
times, determined by palynology
Palynology is the "study of dust" (from grc-gre, παλύνω, palynō, "strew, sprinkle" and '' -logy'') or of "particles that are strewn". A classic palynologist analyses particulate samples collected from the air, from water, or from deposit ...
. Upper Pliocene deltaic sand deposits blanket the formation with the highest top sands located roughly 150 meters below sea level. Measured with 3D seismic data, the Utsira sandstone lies underneath 800–1000 meters of sediment under the sea with a maximum thickness of over 300 meters. The Utsira stretches 450 kilometers north to south and 90 kilometers east to west. In the north and south lie deep sand systems, while in the middle region slimmer deposits cover the seafloor. The Tampen area, located in the most northern region, contains lean deposits of glauconitic sand.
See also
*Carbon sequestration
Carbon sequestration is the process of storing carbon in a carbon pool. Carbon dioxide () is naturally captured from the atmosphere through biological, chemical, and physical processes. These changes can be accelerated through changes in land ...
References
External links
Sleipner in Interactive Energy Map
{{DEFAULTSORT:Sleipner Gas Field
Natural gas fields in Norway
North Sea energy
Equinor oil and gas fields
ExxonMobil oil and gas fields
TotalEnergies
Carbon capture and storage