The Finn is Sebastian Vettel's nearest rival in the world championship, having delivered a run of second place finishes as well as victory in the season-opener in Australia.
Boullier has nothing but praise for the job Raikkonen has done.
"I would have to give Kimi 10 out of 10," Boullier told the Lotus website as part of a review of the first half of the campaign.
"He's done a terrific job right from the beginning of the season and his remarkable run of 27 consecutive points finishes speaks for itself.
"No matter what happens he's always there, as we saw in the final few laps at Monaco. He is playing a big part in pushing the team forwards, and of course having such a popular character in the seat has its advantages too."
Boullier believes that Raikkonen's team-mate Romain Grosjean still has room for improvement, but he has faith the Frenchman can deliver what is required of him.
"For Romain it was a more difficult start to the year coming off the back of a tough season in 2012, and it maybe took him a little while to settle down and start performing to the best of his ability," he said.
"With that in mind, it gives me great pleasure to see him learn from those experiences and to really start delivering the kind of results we've always known he is capable of.
"In Germany and Hungary he really put together the complete package over two consecutive weekends, and this should now be his baseline.
"He knows that if he wants to be winning races and fighting for championships then he must deliver this kind of quality drive at every grand prix.
"If he can keep up this level, Romain can be a future contender for titles, I'm sure of it."