Building and testing of a fully qualified subsea system prototype for production of Sulphate free or low salinity water.

Primary Objective was to build and test a full-scale subsea prototype treatment system to demonstrate that the SWIT technology combined with a purpose designed membrane plant will remove selected ions (e.g. SOH2 / Na+, Cl-) from seawater for a duration of two years or more. Secondary Objectives: - Provide confidence to operators that the technology is -ready to go- for a specific field application. - Prove that the treatment system will be capable of producing water that is tailor made for injection into any specified reservoir. - Verify design data from previous phases of testing. Results of the Project: This project resulted in a full-scale subsea prototype treatment system that provides the final stage in confidence to Operators for subsea water treatment technology: - Technology Readiness TRL 4 (as per API 17Q) - Actual dependability data (availability, reliability, recoverability, maintainability) The successful running of the full-scale subsea prototype system proved it available for an actual field application. Brief Description of Pilot Test: The pilot test plant consisted of four basic water treatment modules. Each module required specialist consideration during construction. Supply of these modules was from different locations in Norway. Module assembly was done at mechanical workshop at Tau, Norway. Local content was maximized during the assembly and interfacing stages. Testing was done at a suitable key facility at Tau Norway with access to deep seawater and utilities (power). Testing included: installation procedure verification, treatment system performance data, reliability, availability and maintainability results. The test and project close out were at 15 November 2019. All project objectives were met.

The benefits are significant from many different aspects like reduction of environmental impact and added values for operators and the society at large - some of the principle benefits are: - Reduced carbon footprint save up to 50% on energy usage for water treatment subsea versus topside for a low salinity scenario The technology enables more cost-effective access to water injection for IOR and EOR applications and thus higher overall recovery rates from NCS and also in a global market Enables water injection of water qualities with low sulphate and low salinity also for an unmanned field development. Vastly reduced host requirements due to unmanned philosophy up to 90% of topside deck weight reduction Overall increased utilization of topside facility, more barrels produced Reduced OPEX Consumables, Chemicals & Manpower requirements Reduced HSEQ risk exposure, due to reduced topside activities No topside module integration and associated modification uncertainty