Development

Åsgard is a field in the central part of the Norwegian Sea. The water depth is 240-300 metres. Åsgard was discovered in 1981, and the plan for development and operation (PDO) was approved in 1996. The Åsgard field includes the deposits Smørbukk, Smørbukk Sør and Midgard. The field has been developed with subsea wells tied-back to a production, storage and offloading vessel (FPSO), Åsgard A. The development also includes Åsgard B, a floating, semi-submersible facility for gas and condensate processing. The gas centre is connected to a storage vessel for condensate, Åsgard C. Production started in 1999 and gas export started in 2000. The Åsgard facilities are an important part of the Norwegian Sea infrastructure. The Mikkel and Morvin fields are tied to Åsgard B for processing, and gas from Åsgard B is sent to the Tyrihans field for gas lift. The PDO for a gas compression facility at Midgard was approved in 2012. The Trestakk field is tied-in to Åsgard A.

Reservoir

Åsgard produces gas and considerable amounts of condensate from Jurassic sandstone at depths of as much as 4850 metres. The reservoir quality varies in the different formations, and there are large variations in the reservoir properties between the three deposits. The Smørbukk deposit is in a rotated fault block and contains gas, condensate and oil in the Åre, Tilje, Tofte, Ile and Garn Formations. The Smørbukk Sør deposit contains oil, gas and condensate in the Tilje, Ile and Garn Formations. The Midgard gas deposits are divided into four structural segments with the main reservoir in the Ile and Garn Formations.

Recovery strategy

Smørbukk is produced partly by pressure depletion and partly by injection of excess gas from the field. Smørbukk Sør is produced by pressure support from gas injection. Midgard is produced by pressure depletion.

Transport

Oil and condensate are temporarily stored at Åsgard A, then shipped to land by tankers. The gas is exported through the Åsgard Transport System (ÅTS) to the terminal at Kårstø. The condensate from Åsgard is sold as oil.

Status

Work is ongoing to increase the recovery from the field, with focus on further reduction of pressure on the facilities and identification of new targets for infill drilling. Challenges for Åsgard are avoiding minimum flow in the subsea flowlines and depleted reservoirs that impact the drilling window. Installation of the Åsgard subsea gas compressor (ÅSC) in 2015/2016 has accelerated and prolonged gas production from the field. The ÅSC Phase II development is ongoing. Avoiding minimum flow in the subsea flowlines is a challenge for Åsgard production. Third party tie-ins to Åsgard and identification of new resource potential can prolong the lifetime of the facilities.