Rhrosty,
The information I could find shows the Saudi reserves as 265 Billion barrels and the OPEC in total as about four times that.
I suspect that the GBR reserves are unlikely to prove to be anywhere near that.

Foyle, Some more knowledgeable industry experts may well disagree.
But lets assume for a moment that our total reserves of sweet light crude were limited to just 100-150 billion barrels and much larger reserves of NG?
We could and should access it for the simple reason, in use from well head to harvester, it produces 75% less carbon pollution than the highly refined stuff we are importing and using now, understand?
Alternatively and given our economy simply can't support importing an increasingly expensive 85%+ of our needs!
Somebody will decide and allow the shale oil projects to re-emerge.
This product, with all its processing and refining processes, produces 400%+ more carbon pollution, than our traditional sweet light crude.
Simply because our sulphur free sweet light crude can be used almost as is, with just a little filtering, rather than highly energy dependant and carbon creating processing and refining!
The stuff we currently pump into our petrol tanks, has already gone through a doubled refinery process before it hits our shores, and lets not dismiss the transport component from halfway around the world, as insignificant!
Or the ramifications of an increasingly volatile Middle East, or what price we may soon pay at the bowsers, thanks to our patently obtuse reliance on mostly fully imported and highly refined fuel products.
Finally, we will need considerable time and capital, to convert our economy over to a carbon free one.
Where do you suppose that capital is coming from?
Our shale oil reserves perhaps?
And while our total carbon contribution is small? Shale oil has the potential to quadruple it!
Whereas, our own reef resources, in widespread use, have the capacity to quarter it!
Given, for sound economic reasons, we must have one or the other!
Which alternative provides more threat to our remaining and already decimated reef?
Rhrosty.

Foyle, the current problem is the type of vehicles we make and use!
Were we to produce and use carbon fibre vehicles, powered by CNG fired ceramic fuel cells, we would have electric vehicles, with a better range and more power and torque that conventional variants!
Moreover, given ceramic cells don't actually burn fuel, but produce energy in a chemical reaction, virtually the reverse of electrolysis, the emission product is mostly water vapour.
There is therefore, i.e., no real reason to spend a veritable fortune on electrifying rail line tracks, for the purpose of rolling out rapid rail.
Given the combination of on-board CNG and fuel cells, (easy enough on a train) would provide the same power, and given the source, possibly a good deal less total pollution as a bonus.
Making CNG>fuel cell powered carbon fibre vehicles here, would give us the whole wide world as our current market!
Which would be protected for some time by patents, our current lead in moulded carbon fibre production, and simple lead time.
Just this market as our sole province for a time, would allow us to become a virtual manufacturing power house.
As would the widespread introduction of publicly provided, cheaper than coal, thorium power!
As would long overdue, major tax reform and vast simplification, that then in turn, completely removed compliance costs, or current endemic avoidance.
Even so, just the latter two, would see the high tech energy dependant industries of the world beating a path to our door.
And in so doing, cement in place, a far better future for the next generation, than that their parents enjoyed!
Rhrosty.

Many thanks Rhrosty,

When I read << Cogent, credible, thoughtful, informative and well researched article >>, I saved myself the bother of reading it. Your critical assessments have become the hallmark of “Article killer”.