British Transport Police (BTP) joined forces with the RMT union and train operators after concerns increased.
Officers travelled on 350 trains to monitor more than 2,000 workers between Aberdeen, Inverness, Dundee, Glasgow, Edinburgh and Newcastle.
BTP said conduct had "noticeably improved".
Sgt Ashley Forbes said: "It is pleasing that the warnings issued by BTP and the train operators appear, in the main, to have been heeded.
"There will be no complacency and officers will continue to carry out high-visibility patrols at stations and on trains and work with our rail industry partners to tackle the issue.
"We have made it clear that passengers and rail staff, who may also be RMT members, should be able to travel and work without encountering alcohol-fuelled anti-social behaviour, which is often experienced when offshore workers are travelling."
A crackdown on "unsavoury incidents" involving offshore workers travelling on trains to and from the north east of Scotland has been hailed a success.