The three men and one women killed when a Super Puma plunged into the sea off Shetland were remembered at a conference in Aberdeen.
George Osborne paid tribute to the "brave" workers during a speech to the Offshore Europe 2013 conference.
"Our thoughts are with their families, friends and colleagues at this time," he said.
"The book of condolence here shows the depth of feeling for those who lost their lives and were injured."
Earlier Mr Osborne joined delegates in standing for a minute's silence led by conference chair Malcolm Webb.
There were 14 survivors of the crash on August 23 which took the lives of Duncan Munro, 46, from Bishop Auckland, County Durham; George Allison, 57, from Winchester, Hampshire; Sarah Darnley, 45, from Elgin, Moray and 59-year-old Gary McCrossan, from Inverness.
Super Puma flights were suspended following the accident but resumed after experts ruled there was no evidence to suggest a technical problem was to blame.
The Chancellor will travel to the Montrose oil and gas field later in the day, one of the North Sea's oldest.
Mr Osborne said he recognises the "vital" role the oil and gas industry plays in the UK economy and told workers they are not being taken for granted.
The UK Government is committed to playing its part in delivering investment to secure the industry's future, he said.