SCOTTISH ministers have welcomed new research that suggests new gas and water technologies could add decades to the lifespan of oil reserves in the North Sea, according to researchers.

A team at Edinburgh's Heriot-Watt University says it has made a breakthrough in developing methods to maximise extraction from existing fields.

The university's Centre for Enhanced Oil Recovery has been working on a technique known as low-salinity water injection and is researching which fields would benefit most from it.

Conflicting forecasts over the life of North Sea oilfields raged throughout the referendum debate.

Professor Mehran Sohrabi, the centre's director, believes new technologies could be a game-changer for the industry.

He said: "At least half of the original oil still remains in the North Sea reservoirs but there are great challenges in extracting it using enhanced oil recovery (EOR) techniques.

"Following years of research at the university, we now believe we can overcome these challenges."

Low-salinity water injection works by reducing the salt levels in sea water that is already injected into reservoirs.

A Scottish Government spokeswoman said: "North Sea oil will remain a huge bonus to the Scottish economy for decades to come.

"This announcement is another example of the great ingenuity and huge potential of the oil and gas industry in Scotland. Improvements in enhanced oil recovery in future years will be critical to maximising economy recovery in the North Sea, and technological developments will contribute greatly to the achievement of this aim."