Air emissions related to up-stream petroleum operations include carbon dioxide, nitrogen oxides, sulphur oxides (which are products of combustion), methane, volatile organic components (which are the result of the release of hydrocarbons), and chlorofluoro/bromo carbons (which are used extensively for refrigeration and fire-extinguishing). The emission of some of these substances has a localised effect on the environment, while others have a major contribution to environmental problems of global interest, such as greenhouse effects, acid rain and the depletion of ozone layer. The upstream operations contribute to these harmful air emissions and with proper operational practices this contribution can be minimised.
Hazardous atmospheric emissions from oil and gas production operations is an issue which has not yet received adequate and serious consideration. Although the environmental impact caused by the production and transportation of fossil fuels is much lower than that caused by their consumption, nevertheless the upstream operations must be aimed at reducing these impacts. This is especially so since the public image towards the industry is generally hostile. In the context of a growing concern towards the environmental impacts of all industrial activities, the subject is now becoming considered at the board room levels and attempts are being made to evaluate the contribution of the upstream oil industry to the overall emissions. As far as environmental effects of oil and gas up-stream operations are concerned, the issues involved are air emissions (combustion gases, hydrocarbons and chlorofluoro/bromo carbons), waste streams (oil contamination, heavy metals, naturally occurring radioactive materials and chemicals; and wastes associated with drilling operations such as cuttings, chemicals, etc.), decommissioning and abandonment of production installations, and oil spills and oil contamination from tanker operations.
Some environmental issues such as ‘smog’, ‘acid rain’ and greenhouse effect have become almost synonymous in the public mind with air pollution. Such well publicised, and simple terms have been used to describe a multitude of complex chemical processes and have helped to draw attention to the possible effects of air pollution on the environment. Historically in the period following World War II local sources of pollution were the main concern. In the 1960‘s photochemical smog’s, pointed to the automobile as an important contributor. Later the acid rain debate highlighted the possible long-range effects of pollutants; and now the greenhouse effect and global warming is considered to be the most important environmental issue facing human beings. Some progress has been made around the world in reducing air pollution and its ‘local’ ill effects. However, it is now recognised that the long-range air pollution is more serious than its immediate and local effects, but it is more difficult to tackle.
In this paper the main sources of air emissions related to the up-stream petroleum operations and the ways to minimise these emissions are discussed.
Detailed effects of major air emission products Air emissions related to the upstream oil industry include carbon dioxide (CO2), nitrogen oxides (NOx), sulphur oxides (SOx), methane (CH4), volatile organic compounds (VOC), chlorofluoro/bromo carbons (CFC's), particulates etc. The emission of some of these substances has a more localised effects on the environment (e.g. VOC), while some others (e.g. carbon dioxide) have a major contribution to environmental problems of global interest like the greenhouse effect and acid rain.