Assessing environmental impact of discharge to sea from producing subsea installation with DREAM following life cycle thinking: a preliminary study for the environmental footprint

Abstract

The purpose of this study was to quantify the environmental footprint of discharge to sea from a producing subsea installation and its semi-submersible host platform in the North Sea. Portion of environmental burden that could be allocated to each installation was identified. Having no physical discharge point, specific portion produced water and waste generated from subsea installations have not previously been studied. Main concepts and methodology of the established life cycle assessment was followed through life cycle thinking using real data for best estimation of the posed risk and impact. Dose-response risk and assessment model was implemented as currently the best available tool for impact assessment of the complex mixture the discharge is composed of. All sources of discharge during the production phase were identified and assessed, and DREAM results evaluated the subsea contribution to risk by the discharge. A more comprehensive evaluation of all phases of the life cycle including more impact factors is needed to properly evaluate the total environmental footprint by a subsea installation.