As long as the economic incentives are there, that will continue until eventually, there will be no place left to drill we have not.
Improvement in efficiency just means that more marginal resources become exploitable, but that does not 'make' more oil, it just makes some available which would not have been otherwise.
That comes at a cost, and economic factors apply, but at some point, even the most efficient extraction methods will have extracted all that can be removed from the reservoir.
As for reason to think that eventually we will not be able to keep up with the depletion of known reservoirs by discovering new ones?
Yep I do have reason to believe this. I have been working in the industry for 26 years, and recognize that oilfields we have come to take for granted since the '50s either have depleted or are beginning to decline.
There is a reason OPEC, especially Saudi Arabia, cannot drop the price of oil to the point exploration is less lucrative--they no longer have the excess production capacity to control the price that well, especially in the face of increasing global demand. They can create a shortage, but not a glut.
You note increased understanding as one of the keys to avoiding an eventual shortage, but that only comes with experience. Apparently, you are unfamilliar with the industry, which is notorious for boom and bust cycles which have kept tremendous numbers of people scurrying for the security of a steadier employment market. THere are a few of us die-hards who stick it through, but far, far more who do not. Especially in times like these, experienced personnel are at a premium.
Once someone is ensconced in a secure position, home every night, with only a 40 hour workweek, they probably are not coming back to the oil patch, especially if they still feel the sting of the layoffs that came with the last bust cycle.
Last, there are only a finite number of hydrogen and carbon atoms to string into useful chains, and I doubt that natural processes are outstripping our ability to break those molecules up.
Note, I am not addressing when, per se, this 'peak' will occur, only that it will, and the greater the demand for petroleum, the sooner it will happen.
The visible universe is finite. That isn't saying a blessed thing.
"we are drilling the ones where we have not drilled before."
Duh. But in fact, we don't drill even in places where we know there are gobs of oil. Exhibit A, Alaska. Exhibit B, offshore restrictions. Exhibit C, half of Siberia, where capital market inefficiencies prevent sensible exploitation.
"that will continue until eventually, there will be no place left to drill"
Does not follow. It may continue indefinitely, we may drill in new and within old fields (to different depths, with different tech, etc) indefinitely, and we may find more oil in both, indefinitely. We don't know any such thing.
"that does not 'make' more oil, it just makes some available which would not have been otherwise."
A distinction without a difference. And as for making more oil, we have no idea how fast oil is being made, today. We know it is, because there is oil there and it did not pop into existence out of nothing. If it took millions of years to make it biotically, then it still might be being made faster than we are using it, because we do not know whether we are using more than a millioneth of it a year.
Geological processes continue. Biomatter subsides today, is compressed under rock today. There is a rate in as well as a rate out, and since we do not know the rate in, we do not know whether there is net depletion. If natural gas forms abiotically as well, the rate in might be far higher than anybody suspects, because the processes involved may take times much shorter than millions of years.
"oilfields we have come to take for granted since the '50s either have depleted or are beginning to decline."
Um, duh, but the conclusion does not follow. It is well know that individual wells produce the most oil as soon as they are drilled, and trail off thereafter. Every individual site is a declining stream, but it does not follow that their sum is a declining stream when the number of them is not fixed. And in fact, the overall stream has never declined. It has increased continually as long as oil has been used.
As for Saudi Arabia's capacity, they have the oil to swamp present demand and drive the price as low as they please. They might not have that many wells operating, but they could readily drill them. But they don't want to, and why would they? They produce oil at a cost of a few dollars a barrel. They can afford to build as many more wells as they like, with oil at $50. But instead they limit their additions of capacity to what they expect they will actually use to meet present and slightly higher near future demand. It is not in their interest to extract oil faster than the world wants it.
And there is at present no shortage of oil in the world. On the surface I mean, not under it. US and world stocks have built continually throughout the present price spike, which is security related not oil fundamentals related. At these prices, supply exceeds demand. Why would they add gobs more capacity, therefore? Everyone who wants oil at $50 has it.
They might want to discourage development elsewhere. And they have marginally increased production and added capacity for that reason. But as minor shifts at the margin. Fundamentally, they are perfectly happy to sell oil for $50 a barrel. The only concern they might have over it is that $50 oil might call forth so much capacity that is drives oil to $30, hardly a sign of inability to produce.
Meanwhile, all this has been focused narrowly on oil, which is certainly the most economic chemical fuel available. We have hundreds of years worth of coal, without even looking for more. We have gobs of less useful forms that become economical only at higher prices (tar sands, shale, etc). While coal is more economical for electricity generation now, it can also be synthetically converted to liquids - Germany ran WW II on the stuff. Beyond those, we can grow alcohols etc.
Energy simply is not scarce nor practically speaking limited (on scales humans use etc), and all the attempts to convince people it is are impositions on general scientific ignorance, with hardly more thought behind it than "it is finite" - as though anything isn't.