CONCLUSION
71
This study focused on the analysis of the environmental impacts and potential risks related to the
drilling of hydrocarbons for exploration at the level of a drilling perimeter in the coastal waters
of Skikda. It was a question of a drilling simulation of a well according to three scenarios
differentiated by the mode of management of the drilling rejects. The analysis of the offshore
drilling stages as well as the comparison of the environmental performance of the three scenarios
was carried out using the life cycle analysis (LCA) methodology. It turned out that this tool is
relevant for quantifying and comparing the environmental impacts on the marine and terrestrial
ecosystem as well as on humans.
The results showed the major role of drilling fluid losses in the impacts and damage to marine
ecosystems, in particular the toxic risk due to diesel, barite and chemical additives. The
contribution of the latter to marine toxicity (water column and marine sediments) was significant
even in phase 36, where the drilling fluids used are made up of more than 90% water (WaterBased Mud). With regard to the management methods for drilling rejects, stabilizationsolidification treatment had the most significant contribution to terrestrial ecotoxicity because of
emissions to the ground of hydrocarbons and certain metals.
Thus, the results of the LCA can be used to identify areas for improvement and provide some
recommendations:
- Control of formation losses to avoid or at least reduce the toxic risks to which marine species
may be exposed.
- Minimization of the volumes of drilling rejects by separating those generated in the 36" section
(water-based muds) from the oil-based muds generated by the other sections of the well.
- Tracing of chemical additives and replacement with other alternative products to neutralize or
reduce the toxicity of certain metals such as arsenic and barium.
However, the analysis must be further refined by completing the missing data and improving the
quality of the inventory data, especially those of the chemical composition of the fluids, the field
data on the marine hydrodynamics which influences the behavior and the transfer of pollutants.
There is also a need for better knowledge of the biology and population dynamics in the marine
waters and the coastline concerned by the offshore drilling perimeter.
Finally, life cycle analysis can offer a decision-making tool to better ensure and anticipate the
environmental sustainability of this type of drilling by preserving the marine environment and its
resources, especially if its future development is required in Algeria, given the increasingly
variable and uncertain global context.
71
This study focused on the analysis of the environmental impacts and potential risks related to the
drilling of hydrocarbons for exploration at the level of a drilling perimeter in the coastal waters
of Skikda. It was a question of a drilling simulation of a well according to three scenarios
differentiated by the mode of management of the drilling rejects. The analysis of the offshore
drilling stages as well as the comparison of the environmental performance of the three scenarios
was carried out using the life cycle analysis (LCA) methodology. It turned out that this tool is
relevant for quantifying and comparing the environmental impacts on the marine and terrestrial
ecosystem as well as on humans.
The results showed the major role of drilling fluid losses in the impacts and damage to marine
ecosystems, in particular the toxic risk due to diesel, barite and chemical additives. The
contribution of the latter to marine toxicity (water column and marine sediments) was significant
even in phase 36, where the drilling fluids used are made up of more than 90% water (WaterBased Mud). With regard to the management methods for drilling rejects, stabilizationsolidification treatment had the most significant contribution to terrestrial ecotoxicity because of
emissions to the ground of hydrocarbons and certain metals.
Thus, the results of the LCA can be used to identify areas for improvement and provide some
recommendations:
- Control of formation losses to avoid or at least reduce the toxic risks to which marine species
may be exposed.
- Minimization of the volumes of drilling rejects by separating those generated in the 36" section
(water-based muds) from the oil-based muds generated by the other sections of the well.
- Tracing of chemical additives and replacement with other alternative products to neutralize or
reduce the toxicity of certain metals such as arsenic and barium.
However, the analysis must be further refined by completing the missing data and improving the
quality of the inventory data, especially those of the chemical composition of the fluids, the field
data on the marine hydrodynamics which influences the behavior and the transfer of pollutants.
There is also a need for better knowledge of the biology and population dynamics in the marine
waters and the coastline concerned by the offshore drilling perimeter.
Finally, life cycle analysis can offer a decision-making tool to better ensure and anticipate the
environmental sustainability of this type of drilling by preserving the marine environment and its
resources, especially if its future development is required in Algeria, given the increasingly
variable and uncertain global context.