Wood Group employees on Shell platforms stopped work for three hours on Thursday.
North Sea oil workers have downed tools for a second time in a series of offshore strikes.
Wood Group employees on seven Shell platforms stopped work for three hours on Thursday.
It follows a 24-hour strike on Tuesday, the first of its kind seen in the North Sea for 28 years.
Members of both the Unite and RMT unions are expected to carry out further three-hour stoppages on Friday, Saturday and Sunday in a dispute over pay.
They are also concerned about the impact of a recent switch to a three-week working cycle.