A novel approach to the modelling of the extraction life-cycle of depleting fossil fuel resources has been applied to the case of oil and natural gas production within the UK Continental Shelf. This utilises skewed normal production profiles that yield a better representation than do earlier approaches. Simple methods for extrapolating oil and gas demand in the UK have also been devised. The projected oil and gas balances for the period up to 2010 indicate when oil production will cease to meet indigenous consumption, and the increasing need to import natural gas supplies. These results depend quite heavily on estimates of remaining oil and gas reserves. It will consequently be necessary to revise periodically the present projections as more reliable reserve estimates become available.