Utilize the input text as a context reference, choose the right relationship between Sinopec and Beijing from the options. Options: product/material produced, manufacturer, distributed by, industry, position held, original broadcaster, owned by, founded by, distribution format, headquarters location, stock exchange, currency, parent organization, chief executive officer, director/manager, owner of, operator, member of, employer, chairperson, platform, subsidiary, legal form, publisher, developer, brand, business division, location of formation, creator.

Inspectors found that security personnel at the Beijing branch of Sinopec Corp were unfamiliar with how to handle an oil tank fire, Xinhua said.

Answer: location_of_formation