Silva completed his move from Cruzeiro to Real for a reported fee of around €14 million on Friday.
Spanish giants Real apparently beat off strong competition to land the 21-year-old midfielder, who is expected to be used as an understudy to Germany star Toni Kroos at the Santiago Bernabeu.
But Oliveira has tipped Brazil Under-21 international Silva to shine in Madrid, and challenge for a spot in Ancelotti's first team sooner rather than later.
"He [Lucas] is very happy as one of his dreams has come true. Ancelotti has got a real diamond," Oliveira told AS.
"He is a technical player with good vision, he can make precise 30-40-metre passes and has a strong shot.
"He will push those already in his position.
"He will need to adapt now to a new formation but I am sure he will develop alongside the quality at Real Madrid."
Silva is Real's second new recruit of the January transfer window, after they also signed Norwegian wonderkid Martin Odegaard from from Stromsgodset on Thursday.
