Exploration is at an all-time low in the North Sea

Thousands of delegates have been gathering in the city for Offshore Europe, a major exhibition and conference.

Concerns have been raised over the lack of exploration which is under way to find new fields.

Efforts to attract young people into the industry are also seen as a priority.

Offshore Europe is held every two years, providing both a shop window and a talking shop for the industry.

Gradual decline

The last event in 2001 attracted 24,500 visitors from 72 countries.

An estimated 100,000 jobs in Scotland are fuelled by North Sea oil, including about 30,000 offshore workers.

However, those numbers are expected to decline gradually over the next 30 years.

Extending the life of the industry is close to the top of executives' must-do lists.

There is as much oil and gas left in the North Sea as has already been extracted Lewis Macdonald Deputy Enterprise Minister

Exploration is at an all-time low, but companies have shown great interest in the licences to drill in new fields.

The average age of a North Sea worker is now 50, which has also made encouraging young people into the industry a priority.

The Offshore Europe event runs from Tuesday until Friday at Aberdeen's Exhibition and Conference Centre.

Deputy Enterprise Minister Lewis Macdonald said companies had "numerous options" for diversification.

"Aberdeen is the energy capital of Europe, and will remain so for many years to come," he said.