The Reds' 1-0 home win against relegation rivals Millwall on Saturday was countered by wins for fellow bottom-three sides Charlton and Yeovil, but O'Brien believes Barnsley's escapes in recent seasons gives them an advantage.
"We've got the most experience of doing it (surviving) so we definitely can," O'Brien said after his early goal clinched Barnsley their fourth home league win of the season.
"It was a great team performance and it feels good in there," O'Brien told the club's official website.
"All the back four were brilliant. The two centre-halves headed everything.
"I think we have to build on that and take it into each game. It's going to be a scrap into the end of the season and this shows that we're up for it."