Audit, tax and advisory firm KPMG International said that all the national oil companies' directors that it had surveyed said that "a lack of skilled personnel was the biggest threat to their businesses going forward".

The poll, titled ‘Key Issues for Rising National Oil Companies' surveyed executives from the world's leading State-owned oil companies, which controlled 72% of the global oil reserves.

"The rapid growth of the national oil company sector has outstripped the availability of employees in many parts of the world, and it is now a real risk to the future of some of these companies as they, and their contractors, struggle to meet demand and deal with the issues created by a workforce approaching retirement age," said KPMG UK head of oil and gas unit Anthony Lobo.

Some of the world's biggest exporters of oil and gas are now State-owned, including Saudi Aramco, Gazprom and the National Iranian Oil Company, said KPMG.

In an emailed statement, the company added that previous industry layoffs and recruitment freezes at times of low oil prices made the sector unattractive to graduates and, in some areas, the petroleum industry was seen as an "industry of the past".

DECLINING RESERVES

Meanwhile, the smaller national oil companies were more worried about declining domestic reserves and political risk than skills, stated KPMG.

It said that three-quarters of these companies had indicated that declining domestic reserves was the biggest threat to their business, and just under two-thirds cited political risk as their biggest hurdle.

"This report finds an interesting dichotomy between the largest and smaller national oil companies and their concerns," said Lobo.

"It is interesting to note their mutual concern regarding political instability and the risks associated with it, a factor that could affect all companies, large or small."

Lobo added that the growing power of service companies would play a significant role in the future of the industry.