NEW YORK (MarketWatch) — The shale-oil revolution has contributed to a rout in global oil prices. Now, will U.S. shale-oil producers, who have been enjoying boom times in oil, become a victim of their own success?

Not just yet, based on data compiled by the Paris-based International Energy Agency.

The chart above, from the IEA monthly energy report released Tuesday, takes a look at breakeven production costs for several different types of high-cost oil projects, including ultra-deepwater, Canadian oil sands and North American shale (a.k.a., light, tight oil, or LTO).

Specifically, using data from consulting firm Rystad Energy, the IEA maps out how much production from each type of project carries a breakeven price of more than $80 a barrel. The breakeven level is the price at which the net return on an oil project turns positive.

This comes as oil prices extended their rout Tuesday, sending December Brent futures UK:LCOZ4 down $4.18 or 4.6%, hitting the lowest level for the most actively traded futures contract in nearly four years. Nymex West Texas Intermediate crude CLX24, , the U.S. benchmark, plunged more than $4 to end at $81.72 a barrel, the lowest finish since June 2012 and the biggest one-day drop in nearly two years.

According to the IEA analysis, just slightly more than 4% of this year’s U.S. LTO production carried a breakeven price of $80 a barrel or more. That’s less than 200,000 barrels a day. Overall, around 8% of high-cost production worldwide requires Brent crude above $80 a barrel to breakeven, equal to 1.05 million barrels a day or 1.1% of global liquids production, the IEA estimates.

The IEA notes there is a smattering of other more conventional projects around the world that also carry high breakeven costs, sometimes due to big government takes. “All told, roughly 2.6 million barrels a day of world crude oil production comes from projects with a breakeven price in excess of $80 a barrel,” the report said. World oil production was 93.2 million barrels a day in the third quarter.

The IEA cautioned that there is still some uncertainty over what the plunge in oil prices means for the future of shale production. That’s because LTO wells tend to go into decline just months after coming online.

Maintaining, or increasing, production means drilling new wells and producers “will have to examine whether the new wells need higher prices to break even,” the IEA said, noting a “range of speculation whether even $10 a barrel lower prices in the future would significantly affect drilling rates, and hence, growth rates.”

At the same time, analysts have also noted that for many shale producers, a large chunk of production costs — acquiring acreage, contracting wells, etc. — have already been spent. As a result, the more important figure might be “half-cycle” production costs. which analysts at Citi last week pegged at between $37 to $45 a barrel. See: Can Saudis beat North Dakota in an oil price war?

Nevertheless, the carnage in the oil market has understandably translated into heavy selling across the energy sector. The Energy Select Sector SPDR fund XLE, -1.13% is down another 0.6% Tuesday, bringing its decline since the beginning of October to more than 11% and its year-to-date loss to 9%.