The 32-year-old signed a three-year deal with the club last year, but has played a more important role this season at the club.
He said: “I feel proud and ready to play at least two or three more years at this level.
“England is the best of all worlds, where technique, tactics, atmosphere, infrastructure and management combine. It’s like the highest possible level of professional football.
“I thank the heavens every day for letting me taste this amazing life at Chelsea.”
