Only 78 oil wells were drilled last year in the UK Continental Shelf (UKCS), a sharp drop from 121 in 2008. This low level of drilling was last seen five years ago in 2004.
Exploration wells almost halved during 2009, while appraisals were down 25 per cent compared to last year.
The Northern North Sea was the worst hit, with activity down 65 per cent, followed by Southern North Sea at 60 per cent, Central North Sea at 47 per cent and the Moray Firth at 26 per cent.
However, drilling activity witnessed a 23 per cent surge in the West of Shetlands and the Atlantic margin. The first wells were also drilled in the East Irish Sea since 2005.
Graham Sadler, managing director of Deloitte's Petroleum Services Group, labelled these figures as a reflection of the tough year the industry faced in terms of rig availability, oil price volatility and other wider issues.
This year, energy companies are expected to remain cautious in spending, waiting for less volatility in commodity prices and more stable operating conditions.