Shell will formally cease oil and gas production from the Brent Alpha and Brent Bravo platforms in the UK North Sea on 1 November 2014.
Brent Alpha and Brent Bravo are located 186km (115 miles) east of Lerwick. Both platforms have significantly exceeded their original planned life expectations.
The Brent field was discovered in 1971 and began producing in 1976. The license is jointly owned by Shell UK and Esso Exploration and Production.
The Brent field has produced mainly gas since the mid-1990s. It is 186km (115 miles) east of Lerwick, Scotland, in 142m water depth. It has four platforms: Alpha, Bravo, Charlie and Delta.
Brent Delta reached cessation of production (CoP) on 31 December 2011. Brent Charlie remains in production and will reach CoP in the next few years.
Oil production from the Brent field peaked in 1984 at 500,000 bbl/day, and gas production peaked in 2001 at over 1000 Mscf/day.
A Shell spokesperson, said: “As we reach this significant step, we recognise the major contribution of Alpha and Bravo and the efforts of the many people associated with the platforms over the last forty years in the UK Continental Shelf.
“From a technically innovative installation phase through to a long period of operation and production, these iconic platforms have helped to sustain vital North Sea oil and gas supplies. We will now focus on safely decommissioning these assets.”