It plans to store petrol and other fuel at the site, which will be distributed to wholesale customers and petrol stations in the Midlands and South East.
Residents and councillors have already raised concerns about large quantities of fuel being stored next door to the Calor gas terminal.
They also fear the centre could lead to hundreds of tankers driving to and from the terminal every week, clogging up Canvey’s already congested roads.
But Mark Salt, spokesman for BP, insisted fuel would only be transported from the terminal by an underground piping network.
He said: “We will store the fuel on Canvey and pipe it to our main distribution centres in Northamptonshire, Hertford-shire, and Staffordshire.
“There will not be any tankers transporting fuel from Canvey.
“BP has signed a multi-million pound contract for the exclusive use of certain fuel storage facilities on Canvey to meet customer demand.
“Work on the new facility is expected to start in the near future and it will be in use within the next three years.”