Development

Oseberg Sør is a field in the northern part of the North Sea, just south of the Oseberg field. The water depth is 100 metres. Oseberg Sør was discovered in 1984, and the plan for development and operation (PDO) was approved in 1997. The field has been developed with an integrated steel facility with accommodation, drilling module and first-stage oil/gas separation. Final processing of oil and gas takes place at the Oseberg Field Centre. The production started in 2000. Subsequently, several deposits on the field have been developed with subsea templates tied-back to the Oseberg Sør facility: the PDO for Oseberg Sør J was approved in 2003, a PDO exemption for the G-Central structure was granted in 2008, and the PDO for the Stjerne deposit was approved in 2011. A PDO for the Oseberg Field Centre low pressure gas production and power from shore to the Oseberg Sør facility was approved in 2022.

Reservoir

Oseberg Sør produces oil and gas from several deposits in sandstone of Jurassic age. The main reservoirs are in the Tarbert and Heather Formations. The reservoirs are at depths of 2200-2800 metres and have moderate quality.

Recovery strategy

The field is mainly produced with water and gas injection. In parts of the field, water alternating gas (WAG) injection is being used. Water for injection is produced from the Utsira Formation. Some of the structures are produced by pressure depletion.

Transport

The oil is transported from the Oseberg Sør facility by pipeline to the Oseberg Field Centre, where it is processed. It is then transported through the Oseberg Transport System (OTS) to the Sture terminal. The gas is transported via the Omega Nord deposit to the Oseberg Field Centre for processing and then to the market through Oseberg Gas Transport (OGT), either to Statpipe or Vesterled.

Status

Further maturation of drilling targets is a focus area, but lack of available well slots is a challenge. Several projects are under evaluation to increase recovery from Oseberg Sør.