TABLE OF CONTENTS Hydrocarbon leaks and subsequent fire and/or explosion are one of the main threats to offshore exploration and production/processing of hydrocarbon oil and gas. The Piper Alpha catastrophe in 1988 is 'proof' of this. A severe fire on the Bombay High production installation in 2005 reaffirmed the severe threat implied by leaks.
It may be illustrative to consider the vast difference between two incidents in the North Sea that started in almost identical ways, within approximately 24 hours, and ended very differently. Both incidents started with a gas leak. The main characteristics of the two events may be summarised as shown below:
Explosion and fire on Brent A on 5 July 1988.
Explosion and escalating fire on Piper A on 6 July 1988.
| Piper A, 6 July 1988 | Brent A, 5 July 1988 | |
|---|---|---|
| Leak source: | Blind flange | Gasket in a flange |
| Ignition source: | Ignition by unknown source | Probably by deluge |
| Explosion overpressure: | Approximately 0.3 bar | Approximately 0.3 0.4 bar |
| Deluge: | Not initiated, fire water supply unavailable | Started (inadvertently) on gas detection |
| Subsequent fire: | Escalating immediately to other areas | Only few minutes fire duration |
| Final consequences: | Total loss | Significant damage to gas processing module |
| Consequences to personnel: | 167 fatalities | 2 injuries |
The main difference according to this simplified summary was the activation of the deluge system, but it is slightly more complicated than this. The Brent A gas leak occurred on the highest level far away from the accommodation area, whereas the Piper A gas...
