Johan Sverdrup Phase 2

The Johan Sverdrup Phase 2 HVDC project is a significant expansion of the existing power-from-shore system for the Johan Sverdrup oil field in the North Sea. This project increased the field's production capacity and extended power supply to other installations in the Utsira High area.

Project Overview

The Phase 2 development included the construction of a new processing platform with an integrated HVDC converter module. This platform is part of a larger expansion that involved five new subsea systems, 28 new wells, and modifications to the existing riser platform. The HVDC system was designed to transmit power from the Norwegian onshore grid to the offshore installations, reducing CO2 emissions significantly.

Technical Details

The HVDC system for Phase 2 consists of two ±80 kilovolt 100 MW converter stations. One station is located onshore at Haugsneset, near the Kårstø plant on the Norwegian west coast, while the other is integrated into the new processing platform offshore. The system uses Voltage-Sourced Converters (VSC) technology, which allows for efficient long-distance power transmission.

Two high-voltage power cables, each approximately 200 kilometers long, connect the onshore and offshore converter stations. These cables transmit direct current, which is then converted back to alternating current for use on the offshore platforms.

Environmental Impact

By supplying power from shore, the Johan Sverdrup field significantly reduces its carbon footprint. The electrification of the field, including Phase 2, is expected to reduce CO2 emissions by 1.2 million tonnes per year, equivalent to 2.5 percent of Norway's annual emissions. This aligns with Norway's goal of net-zero greenhouse gas emissions from the continental shelf by 2050.

Expanded Power Distribution

The Phase 2 HVDC system not only supplies power to the Johan Sverdrup field but also extends to other installations in the Utsira High area. This includes the Edvard Grieg, Ivar Aasen, and Gina Krog fields, further reducing emissions from these operations.

Project Timeline and Execution

Construction of the Phase 2 HVDC system began in 2019, with commissioning completed in December 2022. The project was delivered on time and within budget, despite challenges posed by the COVID-19 pandemic. The successful implementation of this project demonstrates the feasibility of large-scale electrification in offshore oil and gas operations.

Economic and Operational Benefits

The HVDC system contributes to the overall efficiency and cost-effectiveness of the Johan Sverdrup field. By eliminating the need for gas turbines on the platforms, it reduces operational costs and increases the amount of saleable gas. The stable power supply from shore also enhances the reliability and uptime of the offshore operations.

Interoperability

The Johan Sverdrup project is notable for being the world's first multi-vendor HVDC scheme feeding an islanded offshore AC power system. This demonstrates the interoperability of equipment from different manufacturers in a complex HVDC application. The successful integration of various components from different suppliers showcases the maturity of HVDC technology and sets a precedent for future offshore electrification projects.

Future Implications

The success of the Johan Sverdrup HVDC project demonstrates the technical feasibility and environmental benefits of powering offshore installations from shore, potentially influencing future developments in the North Sea and other offshore regions.