Australia’s offshore regulator the National Offshore Petroleum Safety & Environmental Management Authority (Nopsema) this month slapped a prohibition notice on Noble Drilling’s harsh-environment jack-up Noble Tom Prosser, until problems with its well control system were rectified, threatening to derail progress on Santos’ Spartan-2 appraisal well offshore Australia.

A Nopsema inspector said he was satisfied on “reasonable grounds” that an activity could occur on the rig that would involve an immediate threat to the health or safety of a person.