By Suhair Darin and Robert Harvey

LONDON, May 13 (Reuters) - Attacks on oil refineries linked to the wars in Iran and Ukraine have disrupted nearly 9 percent of global oil refining capacity in recent months, exacerbating a fuel supply crisis and likely delaying the sector's recovery for several months after the fighting ends.

The war in Iran not only reduced energy supplies by disrupting the movement of oil tankers leaving the Gulf, but also dealt the biggest blow to the refining sector since the COVID-19 pandemic in 2020, after damage to facilities and crude shortages forced downsizing.

"The current shortage in the refined products market will continue... especially given the damage to refineries," Saxo Bank analyst Ole Hansen told Reuters.

Oil prices surged, with Brent crude reaching $126 a barrel in April, its highest level in four years. Prices for other products, such as jet fuel, climbed even faster, hitting a record high in March.

The supply shortage has prompted refiners, traders, and retailers to draw on crude oil and fuel stockpiles to meet demand.

Total Energies CEO Patrick Pouyanné said on April 29 that about 500 million barrels of oil had been drawn from stockpiles, adding that the amount could rise to 1 billion barrels given the time needed to restart facilities and supply oil to Asia.

He said, "Even if the war ends quickly, prices are expected to remain at high levels."

The damage caused by the war is exacerbating the energy crisis.

Daily demand for liquid fuel products, such as gasoline, diesel, jet fuel and fuel oil derived from crude oil, is about 104 million barrels.

Data from IIR, which specializes in global energy market information, shows that the war in Iran has disrupted up to 3.52 million barrels per day of refining capacity as of May 7.

Among the affected refineries is the Ras Tanura refinery, which has a capacity of 550,000 barrels per day and is the largest in Saudi Arabia. Aramco CEO Amin Nasser said on Monday that the refinery had resumed operations, although some units were undergoing maintenance.

Two of Kuwait's three refineries, Mina Al-Ahmadi and Mina Abdullah, were attacked by drones. Both reduced their refining rates, as did the 615,000-barrel-per-day Al-Zour refinery, the largest in Kuwait.

IIR stated that the conflict between Russia and Ukraine also resulted in a loss of 1.42 million barrels per day.

Reuters calculations indicate that Ukrainian drone attacks aimed at disrupting the Russian war machine caused the shutdown of approximately 700,000 barrels per day of Russian crude oil refining capacity between January and May at 16 sites.

Analysts at JPMorgan said that the shortage of crude oil in Asia and Europe has led to a decrease in refining capacity of about 3.8 million barrels per day.

IIR stated that the disruptions related to the two wars amounted to approximately nine percent of the global refining capacity of 100.5 million barrels per day.

* Jet fuel and diesel are the most affected

Analyst Killeen Tam of FHE said, "The decline in refinery operating rates in Asia and Russia has had a significant and disproportionate impact on diesel and gasoil prices."

He added, "We are witnessing a shift in the balance in Asia from a strong regional surplus to a large regional deficit."

Official data showed that oil product inventories in Singapore, the global oil hub, hit their lowest level in more than nine months on May 7.

The International Energy Agency warned that Europe could face a shortage of jet fuel as early as June if Gulf supplies cannot be fully compensated for.

In contrast to this shortage, data from Kpler showed that Nigeria's giant Dangote refinery, with a production capacity of 650,000 barrels per day, nearly doubled its jet fuel exports to Europe in April.

Data from the European Commission indicated that diesel prices at EU gas stations climbed to a record high of 2.11 euros per liter in April, reflecting reduced Gulf supplies and the halt in imports from Russia, Europe’s main supplier, due to the Ukrainian war.

It may take months

George Dex, an analyst at Energy Aspects, said the refining sector began the year with limited spare capacity following the shutdowns it experienced during and after the coronavirus pandemic.

IIR data showed that about 9.69 million barrels per day of production capacity was shut down between 2019 and 2026 due to the coronavirus pandemic, operational problems, weak economic viability and the gradual spread of electric vehicles, which is equivalent to about 10 percent of the current operating capacity.

A return to normal will likely take months.

The International Energy Agency expects refining operations in Gulf refineries to decline to 8.7 million barrels per day this year, a decrease of 900,000 barrels per day compared to 2025.

The agency lowered its forecast for Russian crude oil refining operations in 2026, setting it at 4.8 million barrels per day in the second quarter, compared to about 5.2 million barrels per day earlier this year, due to the Ukrainian attacks.