1998 Pitkin, Louisiana catastrophic vessel failure


		AcuSafe Home Page -> October Newsletter
		CSB Releases Report at Sonat Exploration Company's (now El Paso Production Company) Near Pitkin, LA

On September 21, 2000, the Chemical Safety and Hazard Investigation Board (CSB) released its report of the fatal March 4, 1998 catastrophic vessel failure and fire at Sonat Exploration Company's (now El Paso Production Company) Temple 22-1 Common Point Separation Facility near Pitkin, Louisiana.

On the day of the incident, one of the two separation trains was to be put in operation and production was to be initiated from a new well, known as the Temple 24-1 well. This well was located approximately two miles from the facility and was connected to the facility by a pipeline. Facility supervisors intended to purge the pipeline by opening the 24-1 well and using well fluid to displace air out of the pipeline and through a storage tank roof hatch, located at the end of the production train. Purging is a common practice in petroleum production and processing and entails the removal of air from systems that will subsequently contain flammable hydrocarbons. This purging process was initiated and then conducted for approximately 60 minutes, until 6:15 p.m., at which point a separation vessel failed catastrophically, releasing flammable gas that ignited. Gas from the ruptured vessel produced a large fireball, which damaged nearby piping and released and ignited additional flammable materials. Four workers, who were in the vicinity of the vessel when it failed, died instantly due to massive trauma. The separator, four personal vehicles, and a backhoe were destroyed, and there was damage to oil and water storage tanks. Two other workers who were present at the facility at the time of the incident both survived without injury.

One item that is significant about the plant is that it is not subject to Federal Process Safety Management regulations because the facility is an oil and gas production facility. It would be subject only to the general duty clause of the Clean Air Act and OSHA enabling act.

Among the key findings in the CSB report were:

Mechanical and Design Failure

The separation vessel that failed lacked an inlet valve and could not be isolated from an adjacent bypass line containing high-pressure purge gases.
Block valves at the separator and bypass line were closed so the high-pressure purge gases could not be vented and instead accumulated in the separator.
The separator was rated only for atmospheric pressure, but was exposed to pressures as high as 800 psig at the time of the incident.
The separator was not equipped with pressure relief devices. ANSI/API Specification 12J-1992 includes a recommended practice that "all separators, regardless of size or pressure, shall be provided with pressure protective devices...."
The facility was designed and built without effective engineering design reviews or hazard analyses.

Human Factors Issues

Workers at the facility were not provided with written operating procedures addressing the alignment of valves during purging operations.
The CSB could not conclusively determine the timing of the closure of the two bypass line block valves or establish any reason for this action.

The CSB attributed the incident to two root causes and one contributing cause:

Root Causes

Sonat management did not use a formal engineering design review process or require effective hazard analyses in the course of designing and building the facility.
Sonat engineering specifications did not ensure that equipment that could potentially be exposed to high-pressure hazards was adequately protected by pressure-relief devices.

Contributing Cause

Sonat management did not provide workers with written operating procedures for the start-up and operation of the facility.

For more information, the CSB has a page summarizing their activities with respect to this investigation. A copy of the final report is also available at AcuSafe.