Wolfcamp oil field in Texas dwarfs Prudoe Bay discovered in 2016 with over 20 billion barrels.
Also fracking technology allows the recovery of oil from old fields that was previously unrecoverable.
I think the original find at Prudhoe came in over 20 billion. But let's say the Texas shale field was bigger. You still have extraction costs that average in the low to mid $50s. Which is almost double the cost to extract with conventional drilling. So, you replace Prudhoe, but at almost 2x the cost. To keep up with our current growth rate over the next 50 years, you would need 6 to 7 Prudhoes at the old conventional cost.
I'm not saying we can't find oil, I'm saying we have found the cheap, easy to get stuff.