BP begins Texas City investigation

Investigations have begun into the explosion at BP’s Texas City refinery in March, which killed 15 people and injured more than 70. BP America has established a team to investigate the remains of the isomerisation unit — the part of the refinery that exploded — and representatives of the US Occupational, Health and Safety Administration and the Chemical Safety Board are also on-site.

The accident occurred when the isomerisation unit was in turnaround — controlled start-up — after a two-week maintenance shut-down. All of the 15 people killed worked for specialist contractors carrying out maintenance to the refinery; it is believed that they were in a nearby trailer discussing the startup of the ultracracker unit, adjacent to the isomerisation plant and also in turnaround.

The trailer and a nearby catalyst warehouse were badly damaged in the explosion and subsequent fire, BP says.

The causes of the accident are still unknown. The isomerisation unit converts a low-octane feed into a higheroctane product for blending into gasoline, and incorporates a raffinate splitter which fractionates a nonaromatic stream into light and heavy components. Shutdowns are scheduled every one to two years, with the current one started in late February to change the catalyst — a task carried out every ten years. ‘It is obvious that a substantial hydrocarbon vapour cloud came into contact with an ignition source,’ BP says.

The investigation team is currently interviewing workers and collecting documentation relating to the restart of the unit, and how the trailers were placed around the various plants nearby. They are also inspecting the site to verify the state of the important valves and components at the time of the explosion. In the next phase of the investigation, the team will look at the electronic records of the real-time operations data from the plant immediately prior to the incident, and will use this, along with other data, to build up a computer model of the incident.

‘At the conclusion of the factfinding phase, we will turn over to government agencies responsible for investigating the incident copies of all the data, documents and other information we have gathered. We have promised them our full cooperation. It is our hope that this information will help them reach their conclusions,’ states John Mogford, BP America group vice-president.

The analysis phase of the investigation is likely to take several weeks, says Mogford. ‘It is easy to jump to conclusions but in an incident like this it is important we systematically understand all of the contributing factors rather than the obvious ones,’ he comments.