The Colombian forward is wanted by a host of top European teams this winter.
However, Emery wants to build his team around players such as Duran, not cash in on them.
Emery said: “Hopefully, we can be together with Ollie and Jhon here for the next 10 years - or maybe 12 - or 15. It will be fantastic.
“Now, players are extending their careers, and maybe Ollie, with his physical capacity, can play until he is 40 years old. Pepe Reina, he was at Aston Villa, yes? He’s 42 and playing in Italy.
“I’m happy with both strikers, and it’s a privilege for me to train them.
“Every Aston Villa supporter should be proud of how we can have strikers like Ollie Watkins and Jhon Duran.
“One is the reality, and performing always very good, and progressively getting better - that’s Ollie.
“And the other is Jhon who is 21 and we can exploit his potential here. Of course, I don’t know if we are going to keep them here for a long time but hopefully we will.”