In 2009 the operator of the Montara oil field was responsible for the worst offshore oil spill and fire in Australia's history, which destroyed one drilling rig, severely damaged the Montara wellhead platform and saw oil and gas spill into the ocean for almost 75 days about 690km east of Darwin in 77m of water. 

 

The National Offshore Petroleum Safety and Environmental Management Authority last visited the oil field in early September. During the inspection, NOPSEMA officers noted venting/blow down activities had the potential to cause a "Major Accident Event" which could cause a fire and explosion. 

 

An alarming occurrence took place in late August when pressure on the B annulus on the H3ST1 well reached 247psi, which suggested the migration of gas from the A annulus after gas lift was introduced into the well to bring it into production. 

 

NOPSEMA then requested further documentation from the operator which confirmed that PTTEP attempted to bring the well onto production while there was anomalous pressure in the annulus of "unknown root cause" causing further gas lift into the well and increasing pressure to a dangerous level. 

 

"This is contrary to the PTTEP Well Integrity Management document that requires work to be prioritied towards rectification of well barrier protection," the NOPSEMA inspection report said. 

 

The inspector went on to explain that they were confident the risk could result in injury or death to personnel at the facility during Montara surface wells gas lift activities as a result of fire and an explosion. 

 

PTTEP will not be allowed to recommence operations until NOPSEMA is satisfied the company has a thorough safety management system in place. 

 

Since June this year NOPSEMA had become aware of "a number" of operation issues involving the Montara Venture which included cargo pump room piping and corrosion monitoring issues, compressor operation and performance standard management problems and gas lift operational issues. 

 

In August the company struck an agreement to divest and sell its 100% interest in the Montara field to Singapore-based Jadestone Energy. The sale totals around $195 million, and until the deal closes PTTEP remains the operator of the field. 

 

The company's focus is primarily away from Australia in its home country and Southeast Asian more generally, with some big growth options in Africa and the Middle East. PTTEP posted a net profit for 2017 of US$594 million, up 60% on the year earlier despite taking a $558 million hit on its Mariana tar sands project.

 

Energy News reached out to PTTEP for comment but was unable to obtain one before publication.