The Finn is hot commodity with reigning world champions Red Bull Racing keen to sign him as Mark Webber's replacement when the Aussie steps down at the end of this season.
Boullier, though, reckons Lotus is a good home for Raikkonen and hopes the 33-year-old will re-sign.
"I'm very optimistic," the team boss told the August edition of the JA on F1 podcast at jamesallenonf1.com.
"There is a lot of discussion in the press, most of it is irrelevant. It is all about making Kimi comfortable enough to stay and happy to stay. Part of it is done.
"He knows the team and the environment. Now it's about building up the right package. He will then take his decision."
Asked whether Raikkonen's on-track performances had exceeded expectations since his return to F1, Boullier said: "Yes, definitely, above all the expectations. I'm very happy to have him at the team and blossom in such a way."
But while Lotus may be hoping to hold onto their Finnish driver, they did lose one key member of staff earlier this season when technical director James Allison left the team. He has subsequently joined Ferrari.
"It was a big shock through the media and also here," Boullier said. "James was a respected man both technically and as a person.
"The technical structure in Enstone is already flat so while the departure of James is a blow, we can recover straight away."
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