Saudi Aramco has promised to supply the fully allocated volumes of crude oil to three Indian refiners in October despite the drone attacks on its oil processing facilities but has asked at least one refiner — Indian Oil Corporation (IOC) — to accept a partial grade switch.

The IOC is the only state-owned refiner that can process the Arab heavy crude which has a higher sulphur content at some of its nine refineries.

Aramco informed the IOC —India’s largest oil refiner with a 32 per cent market share —that it would give it some volumes of Arab heavy instead of the lighter Arab mix oil.

Arab Mix is a combination of Arab light and heavy crudes.

Reports suggest that PetroChina has also been informed that some of its September-loading light crude cargoes will be swapped to heavier grades with no delays or change in volumes.

The IOC, which recorded a refinery throughput of 72 million tonnes in the financial year 2019, has been changing its crude mix over time in order to boost profitability. Fifty per cent of the crude oil it uses in its refineries constitutes high sulphur crudes. Heavier crudes are cheaper and refiners are, therefore, able to raise operating margins which boosts profits.

The two other state-owned refiners — Bharat Petroleum Corp Ltd and Mangalore Refinery and Petrochemicals Ltd — will get the Arab light crudes in the same quantities that have been contracted.

The switch to the heavier crude became necessary as Aramco’s Abqaiq processing plant was one of the facilities hit on the weekend. It processes crude from the Ghawar, Shaybah and Khurais fields that produce Arab light or Arab extra light.

The BPCL’s head of refineries, R. Ramachandran, told Reuters that his company would get full volumes from Aramco for September and October without any change in the crude grade.

Two refiners, in China and Taiwan, also said Saudi Aramco had told them that there was no change to the loading schedule in September and October. “Saudi has confirmed (to us) that our refinery will fully get its requested loading in September and October. We have not been asked to switch or delay,” a source said.

Saudi Aramco informed PetroChina on Tuesday that some of its loadings of light crude oil for October will be delayed by up to about 10 days, though it will still supply the same grades and volumes of light crude oil requested for October nominations.

In the Asia market, refineries in Japan, South Korea, India and Thailand are main buyers of Saudi's Arab Light and Arab Extra Light.