RIASSUNTO
Abstract
According to regulations relating to implementation and use of risk analysis in the petroleum activities issued by the Norwegian Petroleum Directorate, it is mandatory for an operator on the Norwegian Continental Shelf to establish acceptance criteria for environmental risk in the activities and carry out environmental risk analysis.
This paper presents a 'new' method for environmental risk analysis developed by the company. The objective has been to assist the company to meet rules and regulations and to assess and describe the environmental risk in a systematic manner. In the environmental risk analysis the most sensitive biological resource in the affected area is used to assess the environmental damage. The analytical method is based on the methodology for quantitative risk analysis related to loss of life. In addition it incorporates the effect of seasonal fluctuations in the environmental risk evaluations.
The paper is describing the function of the main analytical sequences, exemplified through an analysis of environmental risk related to exploration drilling in an environmental sensitive area on the Norwegian Continental Shelf.
Introduction
In December 1990, the Norwegian Petroleum Directorate and the Norwegian Pollution Control Agency issued regulations relating to implementation and use of risk analyses in the petroleum activities. The legal basis for the regulation exists by virtue of the Norwegian Petroleum Act and the Pollution Control Act. The regulation require that the operator defines his environmental acceptance criteria and presents an environmental risk analysis related to his operation. Risk is an expression of the probability and the consequences of an accidental event.
The principle of assessing acceptance criteria is discussed and the company criteria is outlined.
The risk analysis is designed to evaluate the environmental effect, probability and consequences of accidental oil spilt at sea. The analysis is done based on concept design and/or operational concept. The first phase is to define the area affected through oil spill simulations and to assess the sensitive biological communities in the area of influence. The second stage is the analytical part starting with the identification of the dimensioning events followed by probability calculations of the events. The further steps are to evaluate the consequences of the dimensioning event and calculation of the environmental risks which will be compared to the acceptance criteria.
If the calculated risk does not fulfil the acceptance criteria, cost effective proposals for risk reducing measures are established and the analysis is repeated. This will continue until the acceptance criteria is fulfilled resulting in an approved concept.
This paper gives only the frame of the analysis (ref. flow diagram) and any detailed informations is omitted.
Environmental Damage
Environment. The environment is defined as the surrounding marine environment which may be affected by an oil spill, covering open sea areas and coastal areas including shoreline.
The functioning of the marine ecosystem is influenced by physical, chemical as well as biological factors, and these ecological factors are regarded as essential for understanding the various processes in marine ecosystems. The interactions of these factors determine the structure of marine communities as well as how the marine ecosystems are maintained.
Seasonal and geographical variabilities iii the physical-chemical environment affect all marine life, and consequently living organisms exhibit varying capabilities for ecological adaptations to changing conditions of existence.
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