Comparative Analysis of Alternative Solutions for Produced WaterManagement in Offshore Environment Based on Life Cycle Assessment andBiodiversity Impact Assessment

摘要

The produced water management represents an important issue for the Oil&Gas industry.This paper illustrates the development and testing of a Life Cycle Assessment-based,phasedmethodology employable to various offshore contexts for the comparative assessment of alternativeproduced water management options(such as injection versus sea discharge),based on their potential effectson the environment.The first phase of the assessment consists in the quantification and the comparison of globalenvironmental pressures resulting from produced water management processes(facilities installation,useof materials,energy consumption,discharges)through the application of a Life Cycle Assessment(LCA),in compliance with ISO 14040 and ISO 14044.The second phase consists in the local impacts assessment.It starts with the definition of biodiversityand ecosystem services values(biodiversity screening)in the Project area using secondary data,such asglobal and local datasets and scientific bibliography,with the objective to relate the sensitive receptorseventually occurring in the area.This phase continues with the Biodiversity Impact Assessment,which isconducted through a matrix approach that evaluates the significance of the impacts on the related receptors.The approach is based on a combination of the following aspects.1.The sensitivity of local biodiversity to the defined impact categories.2.The magnitude of the local impacts.The third and final phase of the process entails a detailed dispersion modelling of the produced waterdischarges into the sea.The discharges into the sea were identified as the most impactful producedmanagement solution in the previous phases.The whole methodology aims at introducing a complete and quantitative assessment to select the mostsustainable design for produced water management,shifting from a broader perspective(LCA considersglobal impact categories),to a local perspective(focused on the natural context of the Project area).