Saudi Aramco has signed a deal with India to research oil refining technology, further cementing ties between the world's biggest oil producer and one of its fastest growing customers.

The accord with state-owned Indian Oil Corp (IOC) comes on the heels of a visit by Indian Petroleum Minister Mani Shankar Shankar Aiyar to Saudi Arabia to secure guarantees of oil supplies.
The deal is "a milestone in the steadily developing energy relationship between Saudi Arabia and India," said Abd Allah Al-Saif, senior vice president of exploration and production at Saudi Aramco.
The two promised to cooperate on developing new technologies for making cleaner fuels, improving refining, and controling corrion.
Saudi Arabia is India's top oil supplier, filling two-thirds of its demand.
India is keen to lock in supplies as its economy expands and standards of living rise, pushing up oil demand at a faster pace. Saudi Arabia wants more markets for its heavier grades of crude oil that are harder to refine.
The technology tie-up is part of a series of cross-border energy partnerships in the pipeline.
"India is a very important country for us, and we usually complement such close relationships by going beyond the supply of crude oil and entering into downstream partnerships. We look forward to achieving such a goal with India," Al-Saif said.
India's Hindustan Petroleum Corp is negotiating buying a stake in Aramco's proposed new 20 million tonnes per year (tpy) Yanbu refinery.
Aramco may buy stakes in IOC's proposed nine million tpy Paradip refinery and HPCL's 7.5 million tpy Visakhapatnam refinery.
IOC and Saudi Aramco have discussed the possibility of building joint crude storage facilities in southern India, IOC chairman and managing director M S Ramachandran said.
He held talks with Aramco president and CEO Abdullah Jum'ah during the Saudi official's visit to New Delhi to attend Petrotech-2005, a four-day oil and gas conference.
IOC plans to build storage facilities in the southern Indian cities of Visakhapatnam and Mangalore to store roughly five million tonnes of crude -enough to meet the country's needs for around 15 days.
India currently holds around three weeks of reserves. IOC has previously sought technical help to build and maintain strategic oil reserves. The Indian government has been planning to build and maintain strategic crude reserves since the mid-1990s.