Conventional crude discoveries plummeted to a record low last year, one of the world's top energy policy advisers said.
And it likely won't get any better any time soon as energy companies gave the green light to the lowest number of new drilling projects in more than 70 years, according to the Paris-based International Energy Agency.
The IEA has warned that insufficient investment could lead to a tightening of global oil supplies. While that might seem like a welcome change in today's oversupplied market, prices could spike sharply higher in the coming years if drillers do not tee up enough new production to satisfy global demand.
Investment levels remain depressed, and exploration spending is poised to fall for a third straight year in 2017, IEA said in a new report.