Premier Oil's Solan field, west of Shetland, was shut-in over concerns about safety on the what was designed to be normally unmanned facility.
The Solan oilfield came onstream in April this year. The to be normally unmanned facility sees oil production stored in a subsea oil storage tank before being offloaded.
According to a notice posted by the UK's Health and Safety Executive (HSE), Aker Solutions was issued with an enforcement notice on 9 September, and asked to comply by 31 October.
The notice said that the firm was unable to demonstrate the scheme for ensuring Safety and Environmental Critical Elements (SECEs) on the Solan installation were suitable.
Aker Solutions, acting as duty holder, decided to shut down oil production on 1 September. It resumed on 4 September, the issues resolved and the notice complied with, according to the HSE.