Well, we all know that conventional oil peaked 10 years ago, right? Or it is at least something we usually read on various website or forums, and that we entered the era of expensive oil, which brought shale and oil sands and NGL etc. to replace the depleting cheap ressource we had.
Actually, conventional oil didn't peak in 2005, and didn't deplete. It increased to new heights in 2014:

Probably went even higher recently with the increases from OPEC, Russia, return of Iran. Of course, without unconventional shale and tar sands, global oil production would not be at the levels of today (and thus causing an oil glut). But conventional oil is the biggest contributor... Just by not depleting. But how did this happened after the thought peak conventional oil happened following a peak in discoveries.
Well... Producers simply drilled new wells in fields that were not yet fully developped (or not at all), but yet discovered. Vankor field in Russia is a typical example. It was discovered in 1988 but only began production in 2009 (21 years later), with 300kb/d aimed to increase to 500kb/d at its peak. And this is not a lone example around the world, some of them being fully developped 30 years later.
Small fields, with reserves of a few millions barrels and rates of less than 10kb/d became also economic to develop with high prices, while they were simply dismissed at the time of they discovery. It's not much, but there is a lot of them, so you end up with big numbers in the end.
EOR is another answer, increasing known reserves from oil fields actually producing, thus increasing the rate. But it is not really new technology, as it began to be applied in the 70's.
But the list of options gets lower as time passes. As we develop all known fields, discover not enough new ones and apply EOR wherever it's possible, only depletion can happen. Price doesn't correlate with bigger discoveries. It increases options on what we found.
So, at some point, conventional oil will deplete and we will have to rely only on unconventional to replace and increase production for our needs. It will be interesting to watch if it is possible.