Thank you for an informative article, Euan! I note that this is not the first place that I have seen these "bumps" occurring along the downslope of a production curve for a large area. My initial guess (and it is purely a guess) would be that these bumps are driven largely by economics - when oil prices rise small fields that were marginal or even uneconomic to develop become profitable to develop. When the next price plateau is established, another bump can occur because more small fields become profitable to develop. Yet the inevitable direction remains down. Oil prices began to gradually rise from roughly 1999 forward towards about $35 per barrel which may have produced the first bump. The subsequent second price rise to where we are today, hovering around $60 per barrel may be driving the second wave of developments since the 1999 peak. Does that infer that we may need to see another plateau between, say, $80-$90 by about 2010 to drive a third bump of small field development (after 2012)? How far below $60 per barrel can the price of oil fall before the profitability of some of these small fields in the second bump of North Sea development comes into question?

I don't expect you to answer those questions, Euan, but I ask them as seed material for further discussion.

GreyZone - the bumps on the decline curve are caused by "sizeable projects" or clusters of sizeable projects - 50,000+ bpd.  It is possible that stronger oil price prognosis gives companies the confidence to go ahead with these developments.  But in the case of next year's bump project, Buzzard, that would probably have gone ahead at $20 / bbl.  I think the reality is in a very mature province like the UK North Sea, these sizeable projects are few and far between, and so when they are developed, they cause a bump.  As we go done the decline curve towards 500,000 bpd, the size of the bumps may become relatively larger.