 Between 1965 and 1968, three oil refineries were developed close to Teesport, thanks to the Phillips Petroleum's development of the Ekofisk oil field in the North Sea.The first two were jointly developed and operated by Phillips and ICI on the north shore of the River Tees at the North Tees Works, just south of Greatham Creek.After processing this facility fed cyclohexane, benzene, toluene and xylene to ICI's chemical plants at Billingham and Wilton.