The 31-year-old, who played in Geelong's 2007, '09 and '11 flags, will officially join the Bombers as a delisted free agent on November 1.
Chapman is expected to sign a two-year incentive-based deal, and he is confident that his new club has the talent to push deep into September in 2014.
"That was probably one of the criteria I did have," he told Gillette Trade Radio on Thursday afternoon.
"If I've got one or two years left, I wanted to go to a team who are not far off and who are a good chance of making it (to the Grand Final).
"In round 18 Essendon were playing Hawthorn for top spot, so they can definitely play.
"I'm very thankful that I'm going to the Bombers, because I do believe we're a big chance next year."
Chapman, who played 251 games for the Cats over 14 seasons, had medicals at both Essendon and Carlton in recent weeks.
But having committed to the red and black, he is preparing to be reunited with former coach Mark Thompson.
"When we had our meeting (with Essendon), they actually didn't have a coach," Chapman explained.
"I asked who the coach was going to be, and they weren't quite sure.
"A couple of days after that Bomber came out and said he would take the job, so that was a bonus.
"Obviously me and Bomber have worked together for a long time, and we have a good relationship, and hopefully that will continue."
Essendon recruiting manager Adrian Dodoro has confirmed that Chapman will be snapped up next week.
"We didn't do it during the free agency period because there were some issues there with his medical, and we obviously had to negotiate his contract.
"There were a couple of little things we needed to sort out, and we've done that, so hopefully on the first [of November] that'll go through.
"We're really looking forward to getting him to the club. I think he'll be fantastic for our younger players, and everyone's really excited about having him."
An ASADA investigation is still hanging over Essendon, but Chapman "hasn't asked any questions to do with any of that.
"It's a bit above my head really. I don't really know where it's at or anything like that."
Instead, Chapman is already training to ensure he is ready to hit the ground running when Essendon begins its pre-season in early November.
He expects to have a half-forward/midfield role next year, similar to at Geelong, and he admits it will be strange if he gets to line up against his former club.
"It's not what I thought I'd be doing; I thought I'd be a Cat for life," Chapman said.
"But now I've been given another opportunity by the Bombers, and I thank them for that.
"Going to a new club will be scary and exciting, and I look forward to meeting the guys and hopefully achieving something pretty special next year."
Twitter: @AFL_AdamMcNicol
