U.S. light tight oil (LTO) production should be on a downward slope through 2017 before an expected rebound in prices resets growth from 2018 through 2021, the International Energy Agency (IEA) said Monday.

The global glut of crude oil, brought about by the surprising resilience of domestic output, hasn’t dissipated enough for a recovery in prices this year, the global energy watchdog said in its Medium Term Oil Market Report (MTOMR). The annual report was presented on the opening day of IHS CERAWeek in Houston.

Following another year of “relentless stock-building, the date of the rebalancing of the oil market has been pushed back to the early part of 2017,” IEA Executive Director Fatih Birol said. In the short-term, don’t expect a “significant increase in prices.”

IEA’s report boosted West Texas Intermediate prices by 6.2% on Monday to $31.4/bbl.

Today marks the first time since the pioneering days of the industry that the world is in a “truly free oil market,” according to IEA. “In today’s oil world, anybody who can produce oil sells as much as possible for whatever price can be achieved…Today, it is the reality and we must get used to it, unless the producers build on the recent announcement and change their output maximization strategy.”

The Americas will continue to dominate oil growth, particularly LTO through 2021, with the United States remaining the No. 1 source of supply growth, adding 1.3 million b/d over the forecast period. Brazil and Canada follow, with each forecast to produce an additional 800,000 b/d.

“Anybody who believes that we have seen the last of rising LTO production in the United States should think again; by the end of our forecast in 2021, total U.S. liquids production will have increased by a net 1.3 million b/d compared to 2015,” the MTOMR noted.

The resilience of U.S. oil production has lent an “element of surprise,” making it difficult to plot the global oil rebalance.

Meanwhile, crude oil production by OPEC, the Organization of the Petroleum Exporting Countries, rises by only 800,000 b/d by 2021 “as lower oil prices force the reconsideration of development projects in the early period of the forecast.”

IEA researchers expect 2016 to be the third in a row when supply exceeds demand. After underpinning a 60% increase in total domestic supplies in only four years, U.S. LTO production gains finally came to a halt last year and should decline by nearly 600,000 b/d in 2016 and another 200,000 b/d in 2017.

However, as the market rebalances, with a corresponding recovery in prices from $30/bbl, “U.S. LTO production growth resumes in 2018,” the MTOMR said.

It’s not only unconventional oil that’s adding to U.S. supply.

“Combined with continued increases from the Gulf of Mexico — often overlooked in the media focus on LTO — and natural gas liquids, the U.S. regains its spot as the No. 1 source of non-OPEC supply growth in the medium-term,” researchers said.

Oil priced at $30/bbl already has postponed “huge swathes” of investment in capacity projects both in 2015 and 2016, and a sustained price recovery is needed to bring them back into play, Birol said.

“The price of oil will not need to recover to the $100/bbl level we saw from early in 2011 to mid-2014 to allow this to happen. Today, we are in an era where abundant resources of oil can be brought to market at costs lower than thought possible just a few years ago.

“This implies that although oil prices should start to rise gradually, the availability of new supply will place a cap on how far and how fast they can go,” unless there is an unexpected spurt in demand growth or a major geopolitical incident.

Some “certainties” that had guided previous MTOMR outlooks “are now not so certain at all.” It used to be a given that if oil prices were to fall to 12-year lows it would lead to strong demand growth; mass shut-in of so-called high cost oil production; and force the largest group of producing countries to cut output to stabilize oil prices.

However, the energy world has been turned on its head because of the surge in U.S. oil production, IEA said.

“For some time now analysts have tried to understand when the oil market will return to balance,” the MTOMR noted. “A year ago it was widely believed that this would happen by the end of 2015 but that view has proved to be very wide of the mark.”

IEA’s researchers said it is “tempting, but also very dangerous, to declare that we are in a new era of lower oil prices. But at the risk of tempting fate, we must say that today’s oil market conditions do not suggest that prices can recover sharply in the immediate future — unless, of course, there is a major geopolitical event.”