e evacuation of the facility. The frequency of TR impairment should be demonstrated to be no more than once in 1000 yrs. It’s a high standard to achieve.
Finally, because of the measures taken in the design and layout of onshore plants, the potential loss of life is much reduced. This is contradicted by offshore installations where the total population is determined to be at risk.
Is Prelude a cause for celebration or concern?
Shell has for many years had considerable expertise and experience in the production, storage and transport of LNG, in many respects world leaders. Society in general has benefited hugely from advances in technology, which are shown in the long term to be to the common good. Such as the North Sea black gold rush of the 70’s. Doing something different, something that has not been done before, is a risky business, and risk takers are needed if mankind is to advance. This FLNG technology is necessary to develop significant sources of isolated gas deposits located under the sea, in many cases in remote locations. So floating LNG is revolutionary, a bold and adventurous move, but is it a step too far? Only time will tell. Will all the design assumptions made by Shell be valid, or are there some critical factors that have been overlooked, or are we simply being expedient as human beings, because FLNG is the only viable economic way to obtain these gas reserves, and these reserves are essential and will benefit many, is it acceptable to close our minds and forget what happened in the past?
Doing something different, we have been here before
When offshore installations were first installed in the North Sea is was the compactness of these facilities, the juxtaposition of many hazardous areas and activities with hundreds of workers constantly present that was the principal concern. What would happen if something went badly wrong? Miles from land the installation would be required to deal with emergencies on its own, and unlike onshore plants, the 200 or more workers on the platform would be all potentially at risk. Big Oil lobbied against this doomsday argument, surely the design of these huge installations, and the plethora of safeguarding systems would restrict the potential of accidents offshore, it did not seem reasonable they argued, that events offshore could escalate such that the installation itself could be destroyed. The then UK labour government set up a committee to look at offshore safety which reported to parliament in 1980. But by that time some 80 installations were up and running. Nothing much was achieved.
Eight years later the world watched in horror as 167 workers died and a huge installation was destroyed. Big oil collectively had assured the British public that the extraction of oil and gas offshore could be done safely, no one could really challenge this although a few tried. But what happened in July 1988 was too awful to contemplate; it just wasn’t supposed to happen. No one foresaw it.
Piper Alpha was destroyed because the heat energy available was unrestricted
The catastrophic consequences of Piper Alpha could not be avoided on that fateful day because the gas stored in the incoming gas pipelines (acting as a storage tank) could not be isolated because there were no Emergency Shutdown Valves (ESDV) in the incoming gas pipeline on Piper, so the gas kept flowing onto the installation. The heat energy released from this ignited gas destroying load bearing structure in minutes, the secondary explosion was caused when the incoming pipeline failed, weakened by the intense heat. Subsequently, following the public inquiry, many measures were taken, including installing ESDV’s and other measures, to reduce the heat energy from an escalating hydrocarbon event. In future, no installation could suffer the fate of Piper Alpha. The industry had the benefit of hindsight. But Prelude turns this safeguarding feature on its head, it casts aside the minimization of heat energy philosophy as if it is no longer important.
Prelude FLNG produces and stores thousands of tonnes of LNG daily
The hull is ess