BP expects 500 jobs to be created in Shetland as part of its plans to bring bumper projects onstream west of the islands.

The numbers working at the giant oil and gas processing terminal at Sullom Voe in Shetland are set to double under plans to upgrade the plant to cope with a big increase in production offshore.

BP and partners are working on plans to instal new facilities that will be required to process output from developments west of Shetland like the massive Clair Ridge scheme.

The upgrade of the Sullom Voe terminal will require more than £500 million total investment.

The new facilities planned for Sullom Voe include a huge plant that will be used to "sweeten" the gas produced along with oil at Clair Ridge. This will involve removing hydrogen sulphide from the gas so it can be used to boost oil production from the Magnus field east of Shetland. Without being sweetened the gas would corrode the pipelines.

Peter Miller, VP of BP's North Sea midstream business, which runs assets like Sullom Voe, said the upgrade work will provide a boost to employment in Shetland that will last for years.

"I can see for the next five, seven, eight years, we will have huge numbers of people employed here," Mr Miller told journalists during a visit to the plant.

He said while around 500 workers go through the gates of the terminal daily that number could increase to a thousand a day.

The new jobs will be in areas including construction and engineering. It is expected a camp will be built in Shetland that will be capable of housing 400 people.

BP and partners are also overhauling the sprawling processing and storage facilities at Sullom Voe to ensure the plant can remain operational for years to come.

The facilities on the 1000-acre site are used to separate oil and gas and to store crude before it is shipped to market in tankers.

Built in the 1970s, Sullom Voe had an expected life of around 25 years when the facility received the first shipment of oil from the Ninian field in 1978. The terminal has handled around eight billion barrels of crude to date, about a third of the total produced in the UK North Sea.

With production set to continue on the United Kingdom Continental Shelf much longer than originally thought, there could be demand for the capacity provided by Sullom Voe for decades to come.

While BP has not finalised longer term plans for Sullom Voe, Mr Miller said it is perfectly placed to be the route used to export the production from Clair Ridge and the redeveloped Schiehallion field.

The fields could produce high volumes for 20 years or more.

Mr Miller noted there may be much more oil and gas to be found off Shetland. Advances in technology, including improved seismic imaging and horizontal drilling, are helping companies to get a much better picture of what lies beneath the seabed.

BP employs around 200 staff in areas like process engineering at Sullom Voe, while around 300 staff work for contractors.

The workforce at Sullom Voe includes Shetland residents and people who work on a rotation system, which involves visits to the islands.

Investment is booming in the North Sea where firms are trying to boost output to cash in on strong oil and gas prices. Global demand for energy is expected to be underpinned for years by economic growth in countries such as China.

In February, Oil & Gas UK predicted capital investment in the North Sea will increase to £13 billion this year after surging to £11bn last year.

The industry body said investments totalling almost £100 billion were in companies' plans, covering an undefined period.