Improved oil recovery with special emphasis on offshore conditions

The remaining oil reserves in the UKCS and Norwegian North Sea are some 18¹ billion barrels. Figure 1 shows a plot of expected recovery factors from 40 UK and Norwegian North Sea fields. The recovery factors have been arranged in ascending order and plotted versus the cumulative percentage of the total initial oil in place from the 40 fields. It can be seen from Figure 1 that the median recovery factor is 42%. The original oil in place in the North Sea is probably in the range of 70 to 120 billion barrels. This gives a residual oil volume of 40 to 70 billion barrels. We conservatively assume that reserves growth of 5% of oil in place can be attributed to improved reservoir management techniques with a further 5% growth through the application of EOR. This amounts to an Improved Oil Recovery (lOR) target of between 7 and 12 billion barrels from the currently discovered North Sea oilfields. In addition we estimate that there remain some 15 billion barrels of oil yet to be discovered, lOR will also expand this resource. There is tremendous target resource for additional reserves to be generated though lOR technology.