II. ENVIRONMENTAL IMPACTS AND RISKS EVALUATION OF OFFSHORE DRILLING
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- The quantities of energy, water and minerals (e.g. bentonite) as well as the chemical
additives used during drilling and the waste treatment processes.
- Emissions to seawater and marine sediments, estimated from the volumes of fluid
circulation losses during the drilling of the well.
- Emissions to air linked to drilling operations on the platform, more particularly the
physical separation of cuttings-fluids by the series of vibrating screens and the vertical
centrifuge.
- Emissions to soils according to the three management scenarios for drilling waste
including their transport offshore and onshore. The simulated cuttings treatment
processes are solidification-stabilization, thermal desorption and centrifugation.
The life cycle inventory of simulated scenarios including the drilling well and the waste
management was based on the reference flows incoming and outgoing which are represented in
the appendix 2.
The life cycle inventory analysis of the offshore drilling system was carried out using the
SIMAPRO7 which is an LCA software developed by PRé Consultant in the Netherlands. It
contains several LCA methods and several databases each containing hundreds of life
cycles of products, processes and other anthropogenic activities (Fig. 19). Thus, the
inventory analysis of well sections and treatment scenarios results in matrices containing more
than 300 emissions and extractions related to the functional unit. The table 5 is an extract from
these matrices showing the incoming flows (water, energy, raw materials) during the drilling and
waste treatment sections; as well as outflows from the system, in particular emissions to water,
soil, sediment and air.
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51
- The quantities of energy, water and minerals (e.g. bentonite) as well as the chemical
additives used during drilling and the waste treatment processes.
- Emissions to seawater and marine sediments, estimated from the volumes of fluid
circulation losses during the drilling of the well.
- Emissions to air linked to drilling operations on the platform, more particularly the
physical separation of cuttings-fluids by the series of vibrating screens and the vertical
centrifuge.
- Emissions to soils according to the three management scenarios for drilling waste
including their transport offshore and onshore. The simulated cuttings treatment
processes are solidification-stabilization, thermal desorption and centrifugation.
The life cycle inventory of simulated scenarios including the drilling well and the waste
management was based on the reference flows incoming and outgoing which are represented in
the appendix 2.
The life cycle inventory analysis of the offshore drilling system was carried out using the
SIMAPRO7 which is an LCA software developed by PRé Consultant in the Netherlands. It
contains several LCA methods and several databases each containing hundreds of life
cycles of products, processes and other anthropogenic activities (Fig. 19). Thus, the
inventory analysis of well sections and treatment scenarios results in matrices containing more
than 300 emissions and extractions related to the functional unit. The table 5 is an extract from
these matrices showing the incoming flows (water, energy, raw materials) during the drilling and
waste treatment sections; as well as outflows from the system, in particular emissions to water,
soil, sediment and air.