Explosion in an Analytical Laboratory
An explosion and fire occurred in a mud logging unit during the final phase of rigging it up. Gas analysers had been calibrated and the flame ionization detection (FID) and total hydrocarbon analyser (THA) modules were left in operation so that they could stabilize. The mud logging personnel were connecting the outside sample points and drains when the explosion and fire occurred.The mud logging unit used FID instrumentation that required hydrogen gas to be piped into the unit to serve as the fuel for the flame within the instrumentation. The piping and hose connections used to supply the hydrogen gas to the unit were neither pressure tested nor checked for leaks; the unit had no gas detection equipment installed to detect either hydrogen or test/sample gas, nor did the hydrogen bottle have any shutdown equipment installed to prevent flow should a leak occur. In addition, the inside connection to the detection modules consisted of polyurethane hose, which was either blown loose or burned off the connector during the initial explosion and fire. This loss of confinement allowed the hydrogen to continue to flow and feed the fire in the mud logging unit.
Event Date
July 22, 1998
Record Quality Indicator
Region / Country
Event Initiating System
Classification of the Physical Effects
Nature of the Consequences
Cause Comments
The direct cause of the leak is unclear, although the lack of regular inspection and of emergency control system paid a roleThe root cause is absence of a risk assessment and of a safety design
Facility Information
Application Type
Application
Specific Application Supply Chain Stage
Components Involved
Flame ionization detector, hydrogen supply line
Location Type
Location description
Unknown
Pre-event Summary
SOME EXPLANATORY INFO:Mud logging = creation of a detailed record of a borehole by examining the cuttings of rock brought to the surface by the circulating drilling medium.FID = A flame ionization detector is a scientific instrument that measures analyses in a gas stream.
Consequences
Number of Injured Persons
1
Currency
Lessons Learned
Lessons Learned
The investigation issued the following requests:1. Lessees, operators, and contractors shall consider equipping compressed hydrogen and other flammable gas bottles or generators that supply gas to mud logging units with automatic shut-off systems.2. Lessees, operators, and contractors shall consider equipping mud logging units that use FID instruments with a gas detection system that provides an audible alarm and shuts in the gas supply when the ambient air reaches the lower explosive limit.3. Lessees, operators, and contractors shall consider equipping FID instrument systems with automatic shut-off systems to shut down both the gas supply and the instrument itself should a flame failure occur.4. Lessees, operators, and contractors shall consider equipping mud logging units with a positive purge system that sounds an audible alarm and shuts down the unit when the purge pressure falls below a minimum level.5. Lessees, operators, and contractors shall review the piping supplying combustible gases to mud logging units to ensure that the piping is constructed of appropriate material.6. Lessees, operators, and contractors shall check the piping supplying combustible gases to mud logging units to ensure that there are no leaks after installation of the piping.
Event Nature
Emergency Action
Unknown
Detonation
No
Deflagration
No
High Pressure Explosion
No
High Voltage Explosion
No
Source Category
References
References
OCS BBS Website on Outer Continental Shelf tracking critical information on the Gulf of Mexico:
Available at https://ocsbbs.com/SafetyAlerts/Item/176
(accessed June 2020)
Alert report by the U.S. Department of the InteriorMinerals Management ServiceGulf of Mexico OCS Region.
available at https://www.bsee.gov/sites/bsee.gov/files/safety-alerts/safety/safety-a…
(accessed June 2020)