Discharges to sea and emissions to the air by the UK's oil and gas industry have been on an overall downward trend over the last 15 years, according to a key report published today (November 29) by the sector's trade body.
The trend echoes the decline of UK oil and gas production together with effective process management and industry's use of best available techniques, says Oil & Gas UK's Environment Report 2016.
The report - containing data reported to industry's regulators - captures the sector's environmental performance to the end of 2015.
Last year industry had its first increase in production in 15 years, and the extraction of more oil and gas resulted in a slight rise in 2015 in the mass of production chemicals discharged and produced water volumes, as well as in emissions of carbon dioxide, nitrogen oxides, carbon monoxide and sulphur dioxide.
However, the proportion of the rise was not as great as the production upturn itself, demonstrating industry's commitment to environmental management, as well as its efforts to minimise emissions.
The average oil in water concentration in produced water last year was less than half of the recommended limit set by the OSPAR Commission.
Industry takes every step to prevent accidental and chemical releases and last year saw the smallest mass on record of accidental oil released to the marine environment. With 82 million tonnes of oil equivalent produced in 2015, accidental oil releases represented less than 0.00002% of total oil production.
While there was a slight rise in the mass of chemicals released last year, almost half was the result of three incidents. The overall mass of chemicals accidentally released between 2010 and 2015 is down 65 per cent.
Carbon dioxide emissions from offshore oil and gas production contributed just over 3 per cent of the UK's total CO2 emissions in 2015 – the same level as the previous year.
The report does show a continuation of a rise in waste materials being returned to shore from offshore. However, part of last year's rise was due to the downturn, as much of the waste came from sludges, liquids and tank washings from mobile drilling rigs being taken off hire.
Mick Borwell, Health, Safety and Environment Policy Director with Oil & Gas UK, said: “The Environment Report comes at a challenging time for the UK oil and gas which is working extremely hard to navigate through the downturn, while maintaining environment and safety standards.
“Despite the UK Continental Shelf being a mature basin with technically challenging production, the overall trend for the last 15 years is downwards for discharges, emissions and accidental releases. Put simply, we are using the same amount of chemicals and emitting less CO2 in the production of more oil and gas.
“Industry is committed to minimising the effect on the natural environment and all operators have an environmental management system which is designed to minimise environmental effect.”
An infographic illustrating the report is also available.