Emissions/discharges from the oil and gas industry in 2008

10/06/2009 Press release 32/2009: There was a reduction in the petroleum industry's discharges of environmentally harmful chemicals to sea in 2008. Emissions of volatile hydrocarbons were also reduced, while carbon dioxide (CO2) emissions were somewhat higher. This is primarily due to a new calculation model for emissions from flaring. The number of acute spills has stabilized at a level that is still too high.

These results emerge in the operating companies' reports on emissions to air and discharges to sea. This reporting takes place in parallel processes to the Norwegian Pollution Control Authoritity (SFT), the Norwegian Petroleum Directorate (NPD) and the Norwegian Oil Industry Association (OLF) in the EnvironmentWeb – a joint database for the authorities and the oil and gas industry.

Production-related discharges to sea

Produced water
Water normally accompanies produced oil. The volume of this water increases as fields age and the reservoirs are depleted. Water production on the Norwegian Shelf amounted to 173 million cubic metres in 2008. The volume of water discharged to sea was 149 million cubic metres, a decline of about ten per cent from 2007. Thirty million cubic metres were injected into the bedrock, which is somewhat more than in 2007.

Oil in produced water
Water that comes up on to the platforms along with the wellstream is either injected back into the reservoir or cleaned and discharged. The average oil concentration (dispersed oil) in the produced water discharged to sea in 2008 was 9.5 milligrams per litre, measured using the ISO method in accordance with requirements stipulated by the SFT and OSPAR (the Oslo-Paris convention). OSPAR's purpose is to protect the marine environment in the northeastern Atlantic Ocean against pollution.

The oil content in produced water is down from 11 milligrams per litre in 2003. The maximum permitted oil content in water discharged from the installations on the Norwegian Shelf is 30 milligrams per litre. The C-tour and Epcon cleaning technologies, which are the most common new measures, have yielded reductions of dispersed oil down to 1.5-2 milligrams per litre on some facilities.

Discharges of chemicals
Chemicals are classified according to the SFT's system, which consists of green, yellow, red or black categories. Chemicals in the green and yellow categories do not have inherent environmentally hazardous properties, while high priority is assigned to substitution of chemicals in the red and black categories.

The total volume of chemicals used in 2008 was 450,000 tonnes, with 129,000 tonnes being discharged, 99.99 per cent in the green or yellow categories. The remaining volumes were injected (97,000 tonnes), re-used or handled as waste. The volumes of chemicals used, discharged and injected remained at about the same level as in previous years.

After the goal of zero discharges of oil and environmentally hazardous substances from the petroleum activities was introduced in 1997, the discharges of black chemicals have been reduced from 228 tonnes to barely two tonnes in 2008. Discharges of red chemicals have been reduced from 3933 tonnes to 15 tonnes in the same period. These figures confirm that the operating companies' work to achieve the zero discharge targets for the Norwegian Shelf yields results. Storting White Paper No. 26 (2006-2007) states that the zero discharge goal for chemical additives has been achieved, but the work to replace chemicals with less environmentally hazardous alternatives shall continue.

From 2007 to 2008, the discharges of black category chemicals have remained nearly stable, while discharges of chemicals in the red category have been reduced by almost 40 per cent.

Acute discharges to sea

There were 173 acute discharges of oil in 2008, 164 of which amounted to less than one cubic metre. The total volume of oil from acute discharges in 2008 was 195 cubic metres. Over the last six years, the number of discharges has remained at about the same level, while there was a marked decline prior to 2002.

The total number of acute chemical discharges in 2008 was 132, which is in the same range as in previous years. The total volume of chemicals has also remained relatively stable, with about 366 cubic metres in 2008.

All acute discharges of oil and chemicals are basically illegal and must be avoided. The number of acute discharges from the oil and gas industry has stabilized at a level that is too high and the sector must work diligently to reduce these incidents.

Emissions to air

In 2008, the total estimated CO2 emissions from the petroleum activities amounted to 13.8 million tonnes, compared with 13.3 million tonnes in 2007. CO2 emissions from the petroleum activities have remained relatively stabile over the past six years, but rose somewhat in 2007 due to run-in problems at the LNG plant on Melkøya near Hammerfest. The increase in 2008 is a result of the fact that the authorities have required the operating companies to use a higher calculation factor for CO2 emissions from flaring offshore. This factor shall be used until the operating companies can set specific factors for each facility, starting from 2009. The total consumption of flare gas shows a decline of 13 per cent from 2007 to 2008, while estimated emissions of CO2 rose by about 0.5 million tonnes as a consequence of this factor.

According to preliminary figures from Statistics Norway (SSB) and SFT, the total Norwegian emissions of CO2 equivalents were 53.8 million tonnes in 2008, which means that the oil and gas industry accounts for 26.6 per cent of the national CO2 emissions. The turbines on the offshore installations are the largest source of CO2 emissions from the oil and gas activities.

In 2008, the total emissions of nitrogen oxide (NOx) were 50 882 tonnes, compared with 53 997 tonnes in 2007. Emissions of NOx have declined somewhat in the last two years.

According to preliminary figures from SSB and SFT, total Norwegian emissions of NOx amounted to 179 000 tonnes in 2008, a decline of eight per cent from the previous year. The oil and gas industry thus accounts for 28 per cent of the national NOx emissions. The turbines on the offshore installations are the largest source of NOx emissions from the activities.

Total emissions of volatile hydrocarbons except methane (nmVOC) amounted to 50 455 tonnes in 2008, which represents a significant decline from 2007 when emissions totalled 76 194 tonnes. Since 2001, total nmVOC emissions from the petroleum activities have been reduced by 80 per cent. These reductions have been achieved through investments in new facilities for removal and recovery of oil vapour on storage ships and shuttle tankers. This reduction has allowed Norway to fulfill its nmVOC commitments under the Gothenburg protocol, an international environmental agreement dealing with reduction of emissions including nitrogen oxides and nmVOC. The agreement came into force on 17 May 2005 and has been ratified by most European countries, as well as the USA.

According to preliminary figures from SSB and SFT, total nmVOC emissions amounted to 170 660 tonnes in 2008. This means that the oil and gas industry accounts for about 30 per cent of the national emissions.


SFT: Ann Mari Vik Green, Head of section for petroleum activities
Tel.: +47 22 57 34 19, mobile: +47 922 47 457, email: ann.mari.vik.green@sft.no 

NPD: Eldbjørg Vaage Melberg, Information adviser
Tel.: +47 51 87 61 00, mobile: +47 957 00 320, email: eldbjorg.vaage@npd.no

OLF: Tom Gederø, Communication manager
Tel.: +47 51 84 65 30, mobile: +47 922 47 082, email: tgh@olf.no


Updated: 04/09/2009