TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractIn 1998 Norwegian oil industry, together with the authorities, initiated the "zero discharge" work. As a result of this cooperation, the target for the Norwegian offshore operators is set to achieve "zero harmful discharges" to the marine environment within 2005. The need for a system to quantify and document the potential harm of different discharges became evident as a result of this, and thus, the Environmental Impact Factor (EIF) for produced water discharges was developed in 1999 (presented at the SPE HSE 2000).This management tool, based on environmental risk assessment principles known from the EUs Technical Guideline Document (TGD) [14], has now been fully implemented in all Statoil's fields in the North Sea. The present paper outlines the utilisation of the EIF as a management tool and environmental performance indicator, and gives a number of practical examples of application of the system. The EIF has since 1999 also been developed further to cover discharges from drilling operations. Several pilot studies have been undertaken during this development, and the present paper gives the status of this activity and shows examples from drilling waste risk assessment in the Caspian Sea and the Faroe-Shetland channel.Further development of the EIF based risk management systems also includes linking air emissions and discharges to sea in a total environmental balance approach. The present paper will outline how this is handled in our present risk management system.

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractReduced environmental impact is the goal when choosing produced water treatment technologies. On the Norwegian sector the method used for quantifying this impact is the Environmental Impact Factor, EIF. This method is computerized in a tool that calculates the environmental impact from each of a number of chemical component groups that are present in produced water.Re-injection of produced water is the preferred option, and mostly used when pressure support is required. This paper, however, describes new treatment technologies aimed at produced water being released to sea. The technologies are suitable for different produced water compositions. The components in the produced water that contribute to the environmental impact are mainly: aliphatic hydrocarbons, heavy aromatic compounds (PAH), alkylated phenols and man added production chemicals. At several Statoil operated fields the corrosion inhibitor and H 2 S scavenger are giving a significant contribution.Several new technologies will be described. Statoil has had a leading role and actively participated in the development and qualification of most of these technologies. The results from this work will be presented. The technologies will include the CTour process, Epcon CFU, droplet coalescing technologies as well as new technologies to reduce discharge of production chemicals.The main conclusion is that knowledge is needed about which compounds contribute to the environmental impact of produced water before deciding which technology to use.