Australia's offshore energy regulator has halted Santos' drilling campaign at the Barossa gas field over concerns regarding the safety of drilling equipment. 

The prohibition notice issued by NOPSEMA to Ensco Australia, a contractor that has now been bought out by Valaris, came after inspectors identified issues with the blowout preventer (BOP) system, which was prompted by safety concerns on the Valaris MS-1 platform. 

The inspector reported that continuing drilling operations with the "non-compliant" and "degraded" could lead to a "well blowout, resulting in a potential major accident event with serious or fatal health consequences to workers." 

 

According to the prohibition notice seen by ENB, the inspector found the lower pipe rams on the BOP failed the pressure test required once the BOP had been landed subsea. Additionally it was found that the BOP's Ram functionality in an emergency had been reduced to one set of pipe rams, rather than the minimum requirement of two sets of fully functional and tested pipe rams with locking capability. 

The notice also states that Ensco/Valaris had previously been warned that NOPSEMA considered the BOP to be non-compliant and had failed to take any action. 

Ensco/Valaris has been ordered to secure the BR N1 1 well as soon as possible using the most suitable method, to bring the BOP to surface to repair it and return it to compliance and to implement such controls as necessary to reduce risk at the facility to as low as reasonably practicable (ALARP).

In 2021 the Norwegian offshore safety authority found serious breaches of regulations on another Valaris rig following an investigation of an incident from September 2020, which occurred while the rig was working for Equinor.

A spokesperson for Santos told ENB that the notice was not issued in response to a safety incident and there is no threat to people, property or the environment.

"NOPSEMA ordered repair of a piece of equipment that is part of the blowout prevention system. NOPSEMA's notice followed a routine inspection. Valaris is making the repair and expects to resume drilling later this week. There is no impact to the Barossa schedule. The rig's remaining work is to complete two of six wells, with the four completed wells already sufficient to achieve Barossa's nameplate capacity," said the spokesperson.

Valaris has also been contacted for a response.