THE continued strength of the Aberdeen economy, as the oil money kept pumping ashore, was a seemingly reliable constant as the rest of Scotland was buffeted by the economic turbulence of the last few years.

If you wanted to find where hotel revenues were rising fastest, where luxury car sales were soaring or even the best performing John Lewis outlet in the UK you cast your glance towards the north-east corner of the country.

But Wood Mackenzie's annual review of the oil and gas industry should be compulsory reading for those, whether in Holyrood or the granite city, who take its ongoing prosperity for granted.

Investment levels in the UK oil and gas industry are at record levels. But the consultancy's cautious view on its longer term prospects will be a surprise to many.

The North Sea industry is being squeezed between the costs of pursuing increasingly difficult projects, such as those mooted for the deep waters west of Shetland, on one side, and the rising cost of equipment and staff on the other.

Most worrying of all, recent exploration work is throwing up few opportunities to be exploited over the longer term. This highlights the importance of continued improvements in technology, of sensible consistent tax policy and intelligent husbandry of the remaining oil and gas reserves for the North Sea industry's long-term future.

Meanwhile, Aberdeen's oil companies will no doubt continue doing what they have been doing for some years: offering expertise built up over decades in the North Sea to customers across the globe.