Of course oil is limited, but I suggest there is more out there than you might expect. Consider: Half the oil wells in the world are in the US. I doubt that half the oil is / was in the US. But it is easier to develop wells here because of our property rights laws. In many countries you don't own the mineral rights under your property. The government owns the rights. So who has the incentive to explore and develop? If you find a seepage, your incentive is to keep quiet so they don't come in and make a mess on your place.
In 1972, in the book "The Limits to Growth" the "experts" predicted we would be out of oil by the 1990's, & the peak oilers claimed an earlier date. But predictions of the end of oil coming soon have been going on since the 1920's and they were always wrong. The peak oil prediction came true only for the US, not the world, in about the 1970's because the US banned offshore drilling as a result of the Santa Barbara disaster and that was an artificial peak due to politics, not related to technology or actual reserves.
Also, 70% of the earth's surface is under the ocean. Mostly we have only explored around the edges. There's a lot more area that can be explored and developed as technology evolves.
In the US now, horizontal drilling, not fracking, is behind the boom. Fracking has been going on a long time. Horizontal drilling combined with fracking will get going some time in the future in other countries & they will become bigger producers than they are now. It's expensive and a price of around $100 per barrel is needed to keep it profitable. Same with tar sands, but those costs are coming down. Because of these costs, don't expect the price of gas to drop much.
It's the doom & gloom folks who get the headlines. Who predicted in 1990 that we would have an oil boom in the US by now? Hardly anybody. But plenty predicted the end of oil. And even as recently as 2005, did anyone predicting an oil boom get the headlines? Just about zero. Always be a skeptic when it comes to predictions, always. Especially the farther out they predict the more likely they are to be wrong.
Remember how Yogi Berra might have put it: "Don't trust predictions, especially about the future".