Montara oil spill report

Background

The Montara Development Project is possessed and run by PTTEPAA, a subsidiary of this Thai organization PTT Exploration and manufacturing Public business restricted (PTTEP). The Development is situated in a remote area of the Timor water, more or less 250km north‐west of the west Australian coast, and very nearly 700km from Darwin.

The Montara oil spill occured after a blowout and fire from the Montara wellhead system. The blowout happened regarding the H1 well on August 21, 2009 while the western Atlas jackup drilling rig had been operating over another well at the time. Sixty-nine employees had been properly evacuated from the drilling rig. The leak carried on for 74 days, until an intervention really had been effective on its 5th attempt on third November and dirt ended up being moved into 'kill' the well.

The Thai operator estimated that the circulation of oil might have been between 1000-1500 drums each day during the early phases and declined to 400 barrels a day later on. Overall it's estimated that 30, 000 barrels were spilled (plus presumably a good deal of fuel and/or condensate). The total area over which oil or sheen ended up being observed in the past or another had been around 90, 000 square kilometres.

The Incident

Through the inquiry: at the time the H1 Well had been suspended in March 2009, not just one well control barrier complied with PTTEPAA’s personal Really Construction guidelines (or, notably, with practical oilfield rehearse).

Relevantly, the 9⅝” cemented casing shoe had not been pressure tested according to the company’s Well Construction Standards, despite major dilemmas having been experienced with the cementing task. Particularly, the cement when you look at the casing shoe was expected to have already been affected because it have been substantially over‐displaced by fluid, causing what exactly is generally a ‘wet shoe’. None for this was recognized by senior PTTEPAA personnel at that time, even though the organization’s contemporaneous documents, like the regular Drilling Report (DDR), obviously suggested exactly what had happened. The multiple problems in doing the concrete task – for instance the failure associated with the top and bottom plugs to generate a seal after ‘bumping’, the failure of float valves and an unexpected dash of fluid – must have raised alarm bells. Those issues necessitated a careful evaluation of exactly what took place, the instigation of pressure-testing and, almost certainly, remedial action. No such careful analysis was done. The issues are not complicated or unsolvable, in addition to prospective solutions were popular and not high priced. It was a failure of ‘sensible oilfield training 101’.

As at April 2009 whenever H1 perfectly have been suspended therefore the West Atlas rig had departed from Montara WHP to carry out various other work, not merely one well control barrier inside H1 perfectly was satisfactorily tested and validated, and another barrier which should have been put in was lacking. Put simply, the H1 Well had been suspended without reference to PTTEPAA’s personal Well Construction guidelines or practical oilfield training.