"I was also keen to have my future settled before we get into the next season."
Despite being troubled by a serious thumb injury, Rapira still played 21 matches, including the NRL grand final, in 2011, lifting his career total to 123 appearances since his debut in 2006.
New Warriors coach Brian McClennan said it was critical for the club's future to retain the oldest of the Rapira brothers.
"Sam is a prop of the highest quality. He has proved himself to be one of the best in the game over the last few years," he said.
"While he's still young, he has tremendous experience at both Test and NRL level, invaluable for us as we continue to bring younger players into out NRL squad from the Junior Warriors.
Sam's such a solid person, very much a leader and mentor for those boys. He has a huge role to play for us both on the field and off it."