HOUSTON — With international sanctions lifted, the Iranian government called on its oil industry Monday to open the taps on production, a move that could add to a global glut of crude that has sent prices into a tailspin.
Benchmark prices edged further below $30 a barrel as traders considered the prospect of new oil flowing into a global market already oversupplied by 1 million barrels a day, roughly enough to fuel the needs of every driver in a state the size of Pennsylvania or Ohio.
Iranian news organizations quoted Rokneddin Javadi, the deputy oil minister, as saying that Iran was ready to add 500,000 barrels a day to its output. But some oil analysts doubt the Iranians can deliver all the production they promise.
Iranian production is roughly 2.9 million barrels a day, with much of that sold to customers in Asia given quota allowances to continue imports while sanctions over Iran's nuclear program cut off other outlets. Those sanctions were removed over the weekend as Iran rushed to comply with the agreement.
An additional half a million barrels has been considered the most Iran is capable of producing from oil fields that are aging and in desperate need of investment. But the country has vast amounts stored on shore and in sea tankers, which could increase exports for the next few months at least.
Iranian officials promised to increase production even further, to an additional million barrels a day by the end of the year.
"There is some concern the Iranians can pull a rabbit out of the hat and pull out bigger volumes," said Helima Croft, global head of commodity strategy at RBC Capital Markets, a division of Royal Bank of Canada. "It's not coming at a great time for these barrels to be hitting."
But Croft and other international energy specialists are uncertain or skeptical about how much Iran can produce and export in the months ahead. Some say the government is trying to reassure its population, long suffering under the economic sanctions, that relief is on the way by boasting it can produce so much more oil.
The impact of Western sanctions caused Iranian production to drop about 1 million barrels a day in recent years and blocked Iran from importing the latest Western oil field technology and equipment. So while some of Iran's production could be brought back relatively quickly, larger increases may take considerable time until facilities can be upgraded. That is why analysts question the officials' targets.
"New supplies from Iran will be hard pressed to exceed 300,000 to 400,000 barrels a day," said Sadad Ibrahim Al-Husseini, a former Saudi Aramco executive, who monitors oil field output from throughout the region.
The impact of Iran's production plan might have been even larger had it not occurred on the same day that Oman announced that it was preparing to slash its daily output of 1 million barrels by 5 to 10 percent.
On Monday, Brent crude, the international benchmark, settled at $28.54, down 40 cents, while West Texas intermediate settled at $28.94, down 48 cents.
Whatever the eventual impact of additional Iranian barrels on the market, many energy specialists predict low fuel prices will continue throughout the year, benefiting many consumers in countries like the United States and Japan that still import a lot of oil.
The average price of a gallon of regular gasoline in the United States was a stunningly low $1.89 on Monday, a drop of 7 cents in just a week, according to the AAA motor club. Many homeowners who depend on heating oil, especially in the Northeast, will save several hundred dollars this winter.
Iran, in principle, may now sell oil to its former customers in Europe and elsewhere. But in practice, Tehran may face continued restrictions on use of the dollar because of some U.S. sanctions that remain in effect. The dollar is widely used for oil trading.
Although Saudi Arabia and Iran are members of the Organization of the Petroleum Exporting Countries, their geopolitical differences have long made them oil rivals. And those differences have sharpened as low prices have split OPEC and tensions have increased between Saudis and Iranians over sectarian conflicts in places like Yemen and Syria.
An OPEC report released Monday indicated that the group expects low global prices, which have fallen 70 percent since 2014, to force its rival producers, like the United States, to curb production enough to eventually reduce the glut that has driven prices down.
OPEC predicted in its monthly oil report that 2016 would be "the year when the rebalancing process starts."
The price collapse is putting extreme pressure on oil companies to sell assets or combine, as Suncor Energy and Canadian Oil Sands did Monday in a deal worth nearly $3 billion.
OPEC forecast that the United States would have the world's largest output decline this year as capital spending continues to fall, reducing the number of rigs drilling wells. Overall production, including biofuels, in the United States will fall an average of 380,000 barrels a day this year, to an average of about 13.5 million barrels a day, according to OPEC, whose 13 members include the Arab oil states, and Iran, Nigeria and Venezuela.
Many forecasting groups agree with OPEC that production growth outside the organization will fall as companies defer or cancel projects. On Monday, Royal Dutch Shell said it was exiting an estimated $11 billion effort to extract difficult-to-recover natural gas in Abu Dhabi in the United Arab Emirates because "the project does not fit with the company's strategy, particularly in the economic climate prevailing in the energy industry."
The consulting firm Wood Mackenzie has identified 68 large oil and natural gas projects valued at $380 billion in investments that have been deferred worldwide since prices started falling, affecting 2.9 million barrels of daily oil production. RBC Capital Markets has calculated that projects capable of producing 655,000 barrels of oil a day were canceled, delayed or shelved by OPEC countries alone last year, and this year promises more.
But oil prices could remain under pressure for some time, analysts say, because global inventories are still building. The U.S. Energy Department estimates they will grow an average of 700,000 barrels a day this year, and it does not expect a draw on those inventories to begin until the second half of 2017.