The defender put pen to paper before Chelsea's Europa Conference League win against Shamrock Rovers.
"It’s been an up-and-down journey," said Acheampong. "Football is not always plain sailing.
"The downs have helped me get to this point, and at the moment I’m on a high so it’s really good. It means a lot to sign a new contract, especially because I’ve been here so long.
"To continue the journey is a really proud moment for me and my family. The whole time my family are saying how excited they are for me, and I’m happy I can share it with them."
On working with manager Enzo Maresca, Acheampong continued: "Sometimes it can be hard coming from the Academy to the first team, but everyone is so nice. It’s been really good. It’s all about togetherness. If you have that off the pitch, it will translate on the pitch.
"All the Chelsea players are at such a high level and are doing so well. I can see the talent and how good we are. It’s really exciting when I’m over to train here, and that has given me a lot of confidence, and helped me physically and also mentally as well.
"With Enzo, the small details are really important. He’s nice so I can ask him questions one-to-one and he gives me a lot of advice.
"He gives me a lot of confidence. If the manager is backing you, it’s up to you to show him why, and what you can do on the pitch."
The youngster added: "My goal is to be known as a club legend, so just hard work every day, and doing whatever I can to make it."
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