Powering Up An Offshore Giant

The Johan Sverdrup offshore field is located 160 km west of Stavanger, Norway. The field will have an estimated production peak of about 660,000 barrels of oil equivalents per day. To compare, today’s production on the Norwegian Continental Shelf is less than 2 million barrels. The first phase of the oil field development consists of four platforms.

For the first phase of the Johan Sverdrup offshore field development, the HVDC-system supplied by ABB has a capacity of 100 megawatts. The power link will operate at +/- 80 kilovolt and is scheduled for operation by year-end 2018.

The decision on whether to opt for AC or DC supply from shore is often dictated by distance. AC cables have a certain capacitance per unit of length. The applied voltage generates so called reactive current due to the capacitance. If the cable is very long, eventually the generated reactive current will equal the rated current of the cable, and at that point no rating is left for useful active current.