II. ENVIRONMENTAL IMPACTS AND RISKS EVALUATION OF OFFSHORE DRILLING
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1 - Definition of objectives and scope of study
It is a descriptive step, which mainly includes: (i) the definition of study objectives; (ii) the
definition of the function of the system which informs about the nature of the system, as well as
its role and functionality to which the material and energy flows relate; (iii) the choice of the
functional unit which is a parameter to quantify the system function according to the objectives,
by reporting the energy and material flows of all its processes; (iv) the definition of the limits of
the system.
2- Inventory analysis
It is a set of data collection and calculation procedures, they allow to quantify the flows in and
out of the system along the product life cycle. This analysis begins with a data collection
preparation in which the system subdivides into sub-systems with a schematic diagram of
elementary processes linked by flows. Subsequently, the data are collected from several sources
such as: scientific databases, in situ measurements, bibliographic estimates, scientific journals,
expert advice for each life cycle stage.
3- Impact assessment
Based on the material and energy flows identified, the results of the inventory analysis are
translated into potential impacts, this step allows determining the importance and significance of
the potential impacts of the system studied and it includes three mandatory elements:
1. Selection of impact categories with indicators and characterization models in a manner
consistent with the study objectives.
2. Classification where the results of the inventory analysis are assigned to the
corresponding impact categories.
3. Characterization which allows quantifying the contributions of the different emissions
and extractions of the system’s life cycle to the corresponding impact categories.
4-Interpretation
This step is iterative with the previous three to always ensure that the results obtained are correct
to achieve the objectives of the study. It is also here that an attempt will be made to assess the
robustness of the results, to ensure that the associated uncertainties and variability are well below
that of the differences observed between the environmental performances of the various systems
studied.
_____________________________________________________________________________
48
1 - Definition of objectives and scope of study
It is a descriptive step, which mainly includes: (i) the definition of study objectives; (ii) the
definition of the function of the system which informs about the nature of the system, as well as
its role and functionality to which the material and energy flows relate; (iii) the choice of the
functional unit which is a parameter to quantify the system function according to the objectives,
by reporting the energy and material flows of all its processes; (iv) the definition of the limits of
the system.
2- Inventory analysis
It is a set of data collection and calculation procedures, they allow to quantify the flows in and
out of the system along the product life cycle. This analysis begins with a data collection
preparation in which the system subdivides into sub-systems with a schematic diagram of
elementary processes linked by flows. Subsequently, the data are collected from several sources
such as: scientific databases, in situ measurements, bibliographic estimates, scientific journals,
expert advice for each life cycle stage.
3- Impact assessment
Based on the material and energy flows identified, the results of the inventory analysis are
translated into potential impacts, this step allows determining the importance and significance of
the potential impacts of the system studied and it includes three mandatory elements:
1. Selection of impact categories with indicators and characterization models in a manner
consistent with the study objectives.
2. Classification where the results of the inventory analysis are assigned to the
corresponding impact categories.
3. Characterization which allows quantifying the contributions of the different emissions
and extractions of the system’s life cycle to the corresponding impact categories.
4-Interpretation
This step is iterative with the previous three to always ensure that the results obtained are correct
to achieve the objectives of the study. It is also here that an attempt will be made to assess the
robustness of the results, to ensure that the associated uncertainties and variability are well below
that of the differences observed between the environmental performances of the various systems
studied.