The Norwegian Environmental Agency initiated a study (2014-16) to survey methane and NMVOC emission sources at offshore oil and gas installations. All permanent offshore oil and gas facilities on the Norwegian Continental Shelf (68) were surveyed, including 15 in-depth (full-day meetings with personnel) to identify potential emission sources.
The objective was to quantify emissions, improve quantification, undertake BAT assessments, and identify suitable mitigation measures. The analysis was conducted by a consultant, with participation and data input from companies operating on the Norwegian Continental Shelf, the oil industry association, and other regulatory institutions.
The report found that the existing emission quantification methodology did not accurately account for all emission sources. It identified methane emissions sources and placed them into three categories:
1. Unburned natural gas from gas turbines, gas engines, boilers and flares.
2. Gas emitted from shuttle tankers during loading of oil from offshore installations.
3. Direct natural gas emissions comprising operational emissions (also called cold vents) and fugitive emissions
and natural gas leaks. The direct emissions of natural gas contributed 71% of the methane emissions and
18% of NMVOC emissions from the Norwegian offshore oil and gas industry in 2013.
The study resulted in a more detailed breakdown of emissions by source, and recommendations for methodology improvements. Revised emissions levels were found to be lower than previous estimates, but there were considerable variations between emission sources. The emission abatement potential was found to be around 10%. This summary report is an overview of sources, quantification methods, BAT conclusions, etc. More detail is available in the module reports.