Oil and gas activities

Published by the Norwegian Environment Agency Lag rapport Les på norsk

The oil and gas industry is the largest source of greenhouse gas emissions in Norway, and one of the largest sources of emissions of acidifying substances. The discharges of environmentally harmful chemicals are however rather small.

Slightly increasing oil and gas production

According to the Norwegian Petroleum Directorate, the total production of oil and gas on the Norwegian Continental Shelf amounted to 228 million Sm3 oil equivalents in 2015. Both oil and gas production increased slightly compared to 2014.

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Production forecast for the Norwegian continental shelf

Projections indicate that Norwegian oil and gas production will remain relatively stable until around 2020. Towards 2030, production is expected to decrease.

Impacts of the oil and gas industry

Both oil and gas production itself and the use of oil and gas products generate pollutant releases with local, regional and global effects.

Impacts of emissions to air

Emissions to air from the oil and gas industry include greenhouse gases that contribute to global warming as well as other components with more local effects, such as acidification of lakes. Because there are multiple sources of such emissions and because it takes some time before the impacts of these emissions become apparent, it can be difficult to identify direct correlations between impacts and sources. The oil and gas industry is one of the largest sources of emissions to air in Norway. Main sources are energy production, flaring and fugitive emissions, cold venting and oil storage and loading.

Impacts of discharges to the sea

Discharges of oil and chemicals may cause both acute and long term effects on the marine environment. We know more about environmental effects related to acute oil spills and discharges of drilling fluids and drill cuttings, than we do about other kinds of discharges.

Current knowledge indicates that operational discharges to sea from the oil and gas industry do not have serious impacts on the marine environment. Environmental monitoring suggests that marine organisms are seldom exposed to pollutant concentrations that are high enough to cause a negative impact. This applies both to individual organisms and to populations.

As far as we know, oil and chemical spills from the Norwegian oil and gas industry have not caused significant environmental impacts either. This is largely because there have been few major spills and because these occurred at times of the year when there were no large concentrations of sensitive organisms in the affected areas. The environmental monitoring methods that we use may at the same time be insufficient to detect potential negative effects.

Releases to air, sea and the seabed

Large quantities of pollutants are released to air, sea and the seabed during exploration activities and oil and gas production. This happens at all stages from oil and gas field operation to pipeline construction, transport of oil and gas, and onshore processing. When oil fields are exhausted, decommissioning of installations and equipment will result in further releases of pollutants and generate waste that must be properly disposed of.

Large emissions of greenhouse gases and acidifying gases

Oil and gas activities account for a substantial proportion of Norway's emissions to air. In 2015, the industry generated almost a fourth of the country's greenhouse gas emissions, about 5.5 per cent of its NOx emissions and about 28.5 per cent of its nmVOC emissions.

In 2015, CO2 emissions from Norway's oil and gas activities totaled 13.5 million tonnes, which is a slight increase compared to 2014. Emission levels remained fairly stable from 2001 to 2006. In 2007 and 2008, there was a rise as a result of problems in connection with the start-up of the LNG plant at Melkøya near Hammerfest.

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As fields age and the volume of produced water rises, more and more energy must be used to separate the water from the oil or gas stream and treat it or inject it into geological formations. As a result, greenhouse gas emissions also increase.

Steep reduction in discharges of environmentally harmful chemicals

Currently it is not possible for the oil and gas industry to operate efficiently without using large quantities of chemicals. Roughly one third of the chemicals used are released to the sea.

As a rule, discharges increase with the age of a field. This is because more energy and more chemicals are needed to extract the resources as a reservoir becomes depleted. Both the use and the discharges of chemicals have increased slightly during the last few years. However, the increase is due to chemicals expected to have little or no effect on the environment.

Discharges of environmentally harmful chemicals on the other hand, have been drastically reduced.

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Slight increase in oil discharges

Water in varying quantities – produced water – is always produced along with oil and gas. It contains low concentrations of various naturally occurring substances, including oil components, heavy metals and radioactive substances, as well as production chemicals.

Discharges of produced water and discharges from shipping are the largest sources of oil discharges in the North Sea and Norwegian Sea. Discharges of dispersed oil in produced water on the Norwegian continental shelf totaled 1 820 tones in 2015.

The quantity of produced water generally increases substantially with the age of the oil field. The fields on the Norwegian continental shelf have been producing larger amounts of water than oil since 2004. The decreasing trend in the volume of produced water discharged to sea seen between 2007 and 2013 seems to have shifted in line with prognoses. About 23 per cent of the produced water was injected into geological formations in 2015, while the rest was treated and discharged to sea.

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Oil and chemical spills

There has been no major blow-out on the Norwegian continental shelf since the Ekofisk Bravo incident in 1977, and the probability of another accident of this kind is low. However, if a major spill does occur, both the immediate and the long-term impacts may be severe, particularly for the coastal environment and seabirds.

More recently, there have been few major oil and chemical spills, but many smaller spills. No direct impacts have been identified from these spills.

National regulation and international cooperation

The Norwegian authorities have defined acceptable levels of environmental pressure from oil and gas activities in several white papers. These goals are followed up through laws and regulations, and through requirements in the permits issued to the oil and gas industry.

National regulation of pollution

Through the health, environment and safety regulations for the petroleum sector, and through their permits, the Norwegian Environment Agency sets limits on releases from oil and gas activities.

The Norwegian Environment Agency sets strict requirements for the industry to use less harmful chemicals, reduce releases of pollutants, and at the same time develop new technology. This has brought about reductions in discharges and emissions to the environment. Mandatory environmental monitoring programmes ensure that a watch is kept on the impacts of the oil and gas activities.

The zero-discharge goal, that was introduced in the late 1990's, states that no new petroleum installations on the Norwegian continental shelf can release oil or potentially harmful substances to the sea. On existing fields, steps to achieve this goal were to be taken by the end of 2005. However, there have been delays on some fields.

International cooperation to reduce pollution

Norway is involved internationally to reduce the environmental impacts of oil and gas activities. The most important fora are: