Image © BP p.l.c.
I think we can agree that three billion barrels of oil appears to be a fairly large amount. On one hand we are told that oil is in decline, but then we discover more oil fields and the world continues to turn.
But by how much do finds like these really delay the ultimate depletion of oil? How long will the three billion barrels last?
There are a couple of ways of doing this calculation. First is the gross simplification: divide the amount of oil discovered by the amount of oil consumed globally.
According to BP figures, the world used about 85 million barrels per day in 2008. If we assume BP can recover all 3 billion barrels from Tiber (the new oil field discovered), then it would last the world about 35 days.
The BBC article quotes a BP spokesperson, saying that "... only as much as 30% is extracted from the ground in practice". Given that, the number of days' supply falls to about 11.
That is a fairly poor estimate, though, as it does not take into account the fact that oil production from a new well follows a normal distribution (a bell curve). Production increases as infrastructure and access to the well improves, then peaks, and as the well is a finite resource, starts to decline again. This is also known as a Hubbert Peak.
A better way to consider the impact of this new well is to add its bell curve to the bell curves of all the other oil fields globally. The largest oil field is called Ghawar in Saudi Arabia, producing about 5 million barrels per day and estimated total reserves of 75-83 billion barrels.
Ghawar is but one of the giant fields, others include Burgan, Safaniya and Samotlor, all significantly larger than young Tiber. There are also thousands of smaller ones.
Imagine all these bell curves overlapping one another, adding up to make one very large one (with a definite peak). What is the effect of adding a new discovery like Tiber to it?
The problem is that adding one bell curve to many does not change the average of them by very much at all. In fact, given the relative size of this new field compared with the total, I cannot imagine the peak of the total bell curve shifting by more than a couple of days, if that.
Unfortunately an actual number is beyond my resources to find - I'm sure there are hundreds of highly paid analysts working for BP and others trying to find exactly the same thing.
The point is that, though new oil discoveries do happen, they are simply not of the scale or number needed to push the "end of oil" back very far at all. The chances of finding another super-giant like Ghawar are slim now, and searching in harder to reach places (Tiber is the deepest known field, at about 10km deep) increases cost.
I fear that hoping that new discoveries will continue to allow our current oil consumption is folly of the highest order. Most oil fields are now in decline and, though this is contested, it would appear that oil has most definitely "peaked".
Time for something new. Gas, nuclear, or renewables? Or, in fact, all three, as well as recovering oil from less conventional sources like oil sands/shale.
Sources Used
BBC news story
BP oil usage statistics (BP)
Hubbert Peak Theory (Wikipedia)
Ghawar reserves statistics (foreignpolicy.com)
List of oil fields over 1 billion barrels (Wikipedia)
4 comments:
i think you and ed townes should have a big debate to which everybody can spectate. Or a physical fight
Alas I don't know him, Sean!
You are correct that this one discovery does not change things much. However, the hundreds of other discoveries that never make the news, that take place every day, do change the curve. As of this year, the US has more known supplies of natural gas than at any time in the past, thanks to the discoveries you haven't read about. Currently there are at least ten times (estmates go as high as 300 Billion bbls) more oil than this that has been discovered in North Dakota in the past two years or so- so does that change the curve? As US natural gas technology goes worldwide, the reserves of natural gas are likely to expand several times over, leaving us with centuries of natural gas supplies, which in turn can be converted to other forms of hydrocarbons, hydrogen, and all the other material we use petroleum for. There is no shortage of hydrocarbons. The challenge will be how to use them responsibly. The real folly is in assuming that hydrocarbons are history.
Hi Tony, thanks for commenting.
I didn't include natural gas in my "analysis" of the situation. I know that they are frequently found together, but I assumed that natural gas and oil are independent of each other, given their different uses.
I don't expect hydrocarbon fuels (fossil, not bio) to disappear; in fact I expect gas usage to increase along with coal (hopefully fitted with carbon sequestration and storage technology, but probably not).
Oil however, will probably dwindle, unless effort is put into recovering from oil sands. The non newsworthy discoveries are probably so small as to be negligible, by the logic that if this new one is newsworthy yet ultimately unhelpful then non newsworthy ones would be tiny.
Even another Ghawar would probably only give us another couple of years.
I'm unaware of this North Dakota discovery, can you link me to a reference? 300 billion barrels does seem like rather a lot, and yes, easily accessible oil of that magnitude would make a difference. It sounds more like oil sands, though, which are more costly, less efficient and more damaging than drilling into an oil well. I doubt it would all be recoverable either.
Post a Comment