Oil production in Venezuela, which has been rocked by a crippling economic crisis, spiralling political turmoil and USA sanctions, meanwhile sank by 59,000 barrels per day.
"In terms of crude-oil quantity, markets may be able to adjust after initial logistical dislocations", said the Paris-based IEA, which advises major economies on energy policy.
But, "with the import of diluents now sanctioned by the USA, and problems in producing its own lighter crudes, PDVSA will have a tough job to make enough on spec barrels available for export", the IEA said.
The oil price has risen sharply on Tuesday.
The U.S. bank expects benchmark Brent crude prices to touch $67.50 per barrel in the second quarter of 2019, up from $63.07 per barrel at 0638 GMT on Wednesday.
The cartel made the pledge a year ago alongside major oil producing countries outside the cartel, including Russian Federation, to safeguard oil prices against a global economic slowdown.
The United States' Energy Information Administration said on Tuesday that they intended for the country's crude production to hit a new record in 2020 - around 13.2 million barrels per day.
"This report is bearish", said Phil Flynn an oil analyst at Price Futures Group in Chicago. The dense crudes are much more hard to refine and tend to contain significant quantities of sulfur and other impurities that are costly to remove. OPEC's share of that cut is 800,000 bpd.
In the meantime, the political rift between Venezuela and the United States continues with the US sanctions against the South American nation giving prices a slight boost.
Refineries are built to handle a certain quality of crude, and those which process so-called heavy crude from Venezuela, Canada or the Middle East can not be easily converted to treat the light shale oil that is now being produced in greater quantities in the United States. But a shortfall of heavy-sour crude can cause complications for many refiners, such as those along the U.S. Gulf Coast, configured to process it.
The Organization of the Petroleum Exporting Countries (OPEC) on Tuesday forecast the world oil demand growth for 2019 at 1.24 million barrels a day, slightly lower than the previous month's assessment of 1.29 million barrels a day.
OPEC members along with allies including Russian Federation agreed in early December to trim production by 1.2 mbd from January 1, in a bid to eliminate a production glut and shore up prices.
Venezuela accounted for 16 percent of OPEC output and 8 percent of world production in 1970 but those percentages had fallen to just 5 percent and 2 percent respectively by 2017 (https://tmsnrt.rs/2E4Pfb9).
The recent developments in the crude oil market have all but eliminated the discount enjoyed by heavy crudes, and in some cases, physical cargoes of some heavy grades have traded at premiums to light crudes.