don't believe the naysayers' hype, there's still plenty there. the project cletus is working on has added another 25 years of working life to that platform, and the field i'm going out to will last a good 30-40 years. and there are new fields discovered all the time, but a lot of them are kept quiet. oil companies tend to keep that news to themselves until it suits them to release it, because it can have a massive effect on their share value. according to some sources (which are completely unverifiable without the benefit of hindsight) we hit peak oil in the UKCS in the last decade or so, but to keep things in perspective, that's due to the exponential increase in worldwide demand rather than an exponential decrease in supply.
anyway, one thing that's possibly skewing the headlines is that the offshore decommissioning industry is now starting to kick off. some platforms are 30-40 years old and they're big fucking deathtraps held together with rust, so good riddance to them. a lot of their purpose will be served by the use of lower cost, unmanned subsea installations. which is the fashion nowadays, you rarely need to build big expensive platforms unless it's a huge find or the raw product needs a lot of processing before export.
getting back to the main point - there is still plenty left, and it's being discovered all the time (e.g. 'my' field was discovered in 2001 and was the biggest find in the UK for 10 years, and now unbelievably supplies 10% of the UK's oil supply

)). some of the smaller discoveries are not financially viable to produce yet due to low pressures or difficult rock formations, so their position is logged and they're capped (cemented over) for future development. as i said before, they are usually kept quiet and the oil companies go back to them later when the technology improves & gets cheaper, at which point they become viable. a lot of this is also political game-playing by the oil companies too - you may remember a story a couple of years ago where BP were complaining about the government removing tax breaks for exploration, which made them say that working in the UK is becoming pointless? the smaller oil companies are gleefully moving in cos they can develop these new discoveries for much less money than the old slow-moving dinosaurs.
it's true to say that the majors like BP, Shell, ChevTex etc. are moving gradually out of the UK, but that's cos they're playing the long game - they're thinking of their worldwide plan for the next 40 years, and are gradually moving to more profitable areas like Africa & Eastern Europe/Asia. there are also vast areas of
'oil sands' in places like Canada still to be fully exploited. the technology doesn't make it very viable yet, but when it does the environmentalists will go fucking APESHIT. think of open cast mining in 'protected' National Parks the size of small countries on an epic scale. total permanent destruction just to get a relatively small amount of hydrocarbons out of the ground. by that point we will be scraping the bottom of the earth's barrel to get those last reserves out of the ground.
\end thesis