An official from the regional government said that the hostages were freed late on Wednesday.
"All remaining hostages have been released tonight after intensive negotiations. No one was hurt, no ransom was paid," said a spokesman for the regional governor.
Earlier armed youths released around 60 Nigerian employees of Shell and its subcontractors taken hostage on Tuesday morning when they seized the Shell flow station on the Nun river in Bayelsa State.
Shell, which has not released the identities of anyone held, said there had been no casualties in the attack but said "the Nun river flow station has been shut, resulting in production loss of some 12,000 barrels of oil per day."
The Anglo-Dutch company, which produces about half the total exports of Nigerian crude oil of 2.6 million barrels a day, is losing about 477,000 barrels a day because of recurrent violence in the region.
Over the past nine months, dozens of wells and oil platforms have been closed and workers evacuated.