October 28, 2019January 30, 2020 by Kristin Øye Gjerde

Value creation

by Kristin Øye Gjerde, Norwegian Petroleum Museum

Statfjord is one of the fields on the NCS with the largest production. It yielded four billion barrels of oil equivalent during its first 30 years on stream, twice as much as was thought possible in the original development plan. In addition comes output from the subsea satellite fields.

— Source: Statoil 2012

Converted into cash, Statfjord’s total value creation from 1975 to 2011 was NOK 1 360 billion in 2012 money.

This has benefited the Norwegian government with 756 billion NOK, the licensees with 163 billion NOK, the workforce with 63 billion NOK and the financial institutions and the suppliers of goods and services for development and operation of the field with 378 billion NOK.

Recoverable reserves in the Norwegian share of Statfjord were estimated in 2010 to have originally totalled 3.7 billion barrels of oil (567 million standard cubic metres), 79 billion scm of gas, 20 million tonnes of natural gas liquids and 6.3 million barrels of condensate.

Oil production started on Statfjord in 1979. From the early 1980s production was supported by water alternating gas (WAG) injection. The top level was reached in 1986, and the production stayed on this level until 1994 when it started to decline.

The Statfjord late life project was launched in 2005 to extend the field’s production period and improve recovery of gas and oil. To extract the optimum amount of gas, all water and gas injection ceased in order to reduce reservoir pressure and thereby liberate more gas from the oil.

This approach was intended to increase the field’s recovery factor to 66 per cent for oil and 71 per cent for gas. To achieve that, a total of 60 new wells are being drilled in the late life project.

Only 29 million barrels of oil remained in 2010, together with 15.5 billion scm of gas, 3.3 million tonnes of NGL and 3.1 million barrels of condensate. No final decision has been taken on how long production will continue. (Note! The article was written i 2010. Since then, several life of field extensions on Statfjord have been approved, and the current plan (as of January 2020) allow for production from Statfjord A until 2027 and Statfjord B and C beyond 2035.)